gbt 9222-2008

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ICS 27.060.30

J 98

NATIONAL STANDARD

OF THE PEOPLE'S REPUBLIC OF CHINA

华民共和国国家标准

GB/T 9222-2008

Replace GB/T 9222-1988

Strength calculation of pressure parts for watertube

boilers

水管锅炉受压元件强度计算

Issued on January 31, 2008 Implemented on July 1, 2008

Jointly issued by the General Administration of Quality Supervision,

Inspection and Quarantine of the People’s Republic of

China and the Standardization Administration of thePeople's Republic of China

7/25/2019 GBT 9222-2008


Contents

Foreword...........................................................................................................................................1

1. Scope.............................................................................................................................................6

2 Normative reference.......................................................................................................................6

3 Terms and definitions.....................................................................................................................7

4 General provisions .........................................................................................................................8

5 Material, permissible stress and design temperature......................................................................8

6 Boiler barrel body ........................................................................................................................22

7 Cylindrical header tank body .......................................................................................................40

8 Pipe and conduit in range of boiler ..............................................................................................48

9 Convex head.................................................................................................................................58

10 Flat-end cover and cover board..................................................................................................68

11 Reinforcement of pore................................................................................................................80

12 Odd component..........................................................................................................................93

13 Proof method for determining maximum permissible design pressure of component.............115

Appendix A (Normative appendix) Calculation for boiler barrel's low cycle fatigue life.............124

Appendix B (Informative appendix) Elementary permissible stress of overseas material under

different design temperature J ][ ................................................................................................139

Appendix C (Informative appendix) Approximate calculation for W bending resistance section

factor of open pore weaken cross section .....................................................................................144

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GB/T 9222-2008

Foreword

This standard replaces GB/T 9222 - 1988 "Strength calculation of pressure parts for

watertube boilers". There have been some significant changes in this standard over

GB/T 9222 - 1988 in the following aspects:

Add foreword.

Add scope.

Add normative reference.

Add terms and definitions.

Add general provisions.

Add or adjust elementary permissible stress for parts of usual materials of

domestic boilers (table 1 of 1.3.1 in edition 1988; table 1 and 2 of 5.3.1 in this

edition).

Add elementary permissible stress for parts of usual materials of overseas boilers

(Appendix B of this edition).

Modify scope and value of compensation factor of elementary permissible stressfor boiler barrel body and end socket (Note 2 of Table 2 in edition 1988; Note of

Table 3 of this edition).

Modify selection method of calculating wall temperature (1.4.2 of edition 1988;

5.4.2 of this edition).

Modify definition for thickness of boiler barrel body (2.2.1 of edition 1988; 6.2.1

of this edition).

Extend application scope ofL

in computing formula for boiler barrel body's

theory thickness, permissible minimum attenuation coefficient and maximum

permissible design pressure (2.2.4 of edition 1988; 6.2.4 of this edition).

Modify value-taking method of supplementary pressure designed for boiler outlet

(2.3.1 of edition 1988; 6.3 of this edition).

Add calculation method for equivalent diameter of ladder pore of faulty fusion

through welding (6.4.9 of this edition).

Modify computing formula for additional thickness of boiler barrel body (2.5.1 of

edition 1988; 6.5.1 of this edition).

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Modify rules for selecting processing reduction of boiler barrel body and

additional thickness of thickness lower deviation negative value (2.5.3 of edition

1988; 6.5.3 and 6.5.4 of this edition).

Modify controlling value of difference between maximum inside diameter and

minimum inside diameter of same cross section in parts of high pressure boiler barrel body 2.10.1 of edition 1988;6.10.1 of this edition).

Modify provisions about expanded joint pore on boiler barrel body; centralize

position of down pipe pore and other welded pipe pore (2.10.2, 2.10.3 of edition

1988; 6.10.2, 6.10.3 of this edition).

Modify computing formula for minimum nominal thickness of pipe head of boiler

barrel whose rated pressure is larger than 2.5 MPa; Cancel limit to minimum

nominal thickness of pipe head of boiler barrel whose rated pressure is not larger

than 2.5 MPa(2.10.4 of edition 1988; 6.10.4 of this edition).

Modify definition for thickness of header tank body (3.2.1 of edition 1988; 7.2.1

of this edition).

Modify computing formula for additional thickness of header tank body (3.5.1,

3.5.5 of edition 1988; 7.5.1, 7.6.1 of this edition).

Modify computing formula for technology reduction amount of header tank body

and thickness lower deviation negative addition thickness(3.5.3, 3.5.4 of edition

1988; 7.5.3, 7.6.3 of this edition).

Modify maximum permissible thickness of non-insulation header tank andanti-scorching tank body (table 12 of 3.6.2 in edition 1988; table 12 of 7.7.2 in

this edition).

Modify division method and roundness value of maximum permissible roundness

for cross section of circular arc header tank (table 13 of 3.9.1 in edition 1988;

table 13 of 7.10.1 in this edition).

Modify definition for thickness of pipe (conduit) and computing formula of

thickness (4.2.1 of edition 1988; 8.2.1 of this edition).

Modify computing formula for design calculation addition thickness of pipe(conduit) (4.5.1, 4.5.3, 4.5.4, 4.5.5 of edition 1988; 8.5.1, 8.5.3, 8.5.4 of this

edition).

Modify computing formula for check calculation effective thickness of pipe

(conduit) Add definition for check calculation addition thickness of pipe (conduit)

(4.2.2, 4.5.6 of edition 1988; 8.2.2, 8.6 of this edition).

Modify definition for convex head thickness (5.2.1 of edition 1988; 9.2.1 of this

edition).

Modify conditions convex head structure shall satisfy (5.2.3 of edition 1988;9.2.3 of this edition).

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Modify applicable conditions for computing formula of convex head (5.2.3 of


Modify computing formula for convex head addition thickness; add definition for

addition thickness of convex head check calculation;

Modify reduction value of end socket's stamping technology; make sure

value-taking method for reduction value of convex head's stamping technology

(5.2.8 of edition 1988; 9.2.8 of this edition)

Modify conditions shall satisfy for convex head nominal thickness (5.2.9 of


Modify provisions for minimum thickness control of convex head (5.2.10 of


Delete the provision about "newly manufactured end socket is requested not to be

oblate (5.2.13 of edition 1988).

Add requirements radial minimum residual thickness shall satisfy at kerfs part of

convex head's manhole sealing surface (9.3 of this edition).

Modify definition for flat-end cover thickness (6.2.1 of edition 1988; 10.2.1 of

this edition).

Delete no. 5 structural shape in table 18 of primary standard, add a

full-penetration structural shape; modify provisions about rated pressure and size

applicable to no. 6 structural shape in table 18 of primary standard (6.2.3 of


Modify definition and computing formula for cover board thickness (6.3.1 of


Add structural shape of cover board and its structural property factor K; modify

value-taking method for calculating dimension (6.3.4 of edition 1988; 10.3.4 of

this edition).

Add method to determine maximum allowable pressure of hydraulic test for

cover board (10.3.8 of this edition).

Add structural style that can be treated as reinforcing structure (7.3 of edition

1988; 11.3 of this edition).

Definition and computing formula for 0 , 10 of computation of reinforcement

for modify pore (7.4.4 of edition 1988; 11.4.4 of this edition).

Add application scope and condition for pore and bridge reinforcement (7.5.3 of


Modify definition and computing formula for thickness of welding trifurcatedconnector (4.2.1 of edition 1988; 12.2.1 of this edition).

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Adjust application of computing formula for theory thickness, maximum

permissible design pressure of welding trifurcated connector's main pipe and

branch pipe (8.2.3 of edition 1988; 12.2.3 of this edition).

Revise attenuation coefficient of some welding trifurcated connectorr (8.2.6 of


Cancel primary standard 8.2.11.

Modify open pore provision for welding trifurcated connector and determine

principles of attenuation coefficient (8.2.12 of edition 1988; 12.2.11 of this

edition).

Modify taking principle for hydrostatic test pressure of welding trifurcated

connector (8.2.13 of edition 1988; 12.2.12 of this edition).

Modify open pore provision for hammering trifurcated connector and determine

principles of attenuation coefficient (8.3.5 of edition 1988; 12.3.5 of this edition).

Add calculation method for hot extrusion trifurcated connector (12.4 of this

edition).

Add application scope for calculation of equal-diameter Y-tube (12.5.1 of this

edition).

Add finite element stress analysis and calculation to determine method of

component's maximum permissible design pressure (13.6 of this edition).

Cancel appendix A and appendix C of primary standard.

Appendix B of primary standard is changed to appendix C, appendix D of

primary standard is changed to appendix A.

Appendix A of this standard is normative; appendix B and appendix C are

informative.

This standard was proposed and is under the jurisdiction of China Standardization

Committee on Boilers and Pressure Vessels.

This standard is revised by subcommittee on boiler (SC 1) of China Standardization

Committee on Boilers and Pressure Vessels.

This standard is drafted by Shanghai Generating Set Package Design Research

Institute.

Organizations and staff drafting this standard (sequence is arranged according to

chapters and articles):

Shanghai Generating Set Package Design Research Institute: Li Liren, Zhang Rui,

Zhang Qingjiang, Wu Xiangpeng, Sheng Jianguo, Chen Wei, Yang Wenhu;

Wuhan boiler Co.,Ltd: Xiao Huifang, Tao Shengzhi; Cui Jinxian;

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Dongfang Boiler Group Co., Ltd: Lin Hongshu, Zhang Yuyin, Shen Qiyan, Li

Houyi, Zhai Yaozhong;

Harbin Boiler Company Limited: Liang Jianping, Cao Leisheng;

WuXi Huaguang Boiler Co., Ltd.: Yao Meichu;

Shanghai Boiler Works Co., Ltd.: Feng Jingyuan, Xu Qin, Wu Rusong, Jiang

Shenglong, Shi Yingquan;

National Engineering Research Center for generating set: Zhao Weimin;

Shanghai Industrial Boiler Research Institute: Yu Dezu, Tian Yaoxin;

Thermal Power Research Institute of State Power Corporation: Liang Changqian,

Liu Shutao;

Hangzhou Boiler Group Co., Ltd.: Jin Ping;

Sichuan Boiler Works: Li Lin;

Shanghai Si Fang Boiler Works: Guan Xuefang;

Jinan Boiler Group Company, Ltd: Zhang Qiangjun.

Specially invited expert advisors drafting this standard are: Li Zhiguang, Liu Furen,

Huang Naizhi, Chen Jirong, Xiao Zhonghua, Wu Rusong.

Issuance of all previous editions replaced by this standard:

DZ 173-1962 "Tentative specifications for strength calculation of pressure partsfor watertube boilers”

JB 2194-1977 “Strength calculation of pressure parts for watertube boilers”

GB/T 9222-1988 “Strength calculation of pressure parts for watertube boilers”.

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Strength calculation of pressure parts for watertube boilers

1 Scope

This standard specifies strength calculation method, structure, material requirements

and material permissible stress of pressure parts for watertube boiler; and also offers

verification method for determining maximum permissible gauge pressure of parts.

This standard is applicable to pressure parts, whose rated pressure shall be no less

than 0.10 MPa1), of fixed type water pipe steam boiler and fixed type water pipe hot

water boiler hot-water boiler, such as: boiler barrel body, header tank body, pipes,

pipes in range of boiler, convex head, flat-end cover, cover board and abnormal parts.

2 Normative references

The following documents contain provisions which, through reference in this standard,

constitute provisions of this standard. For dated reference, subsequent amendments to

(excluding corrigenda contents), or revisions of, any of these publications do not

apply. however, all concerned sides make terms according to this standard are

encouraged to research whether latest edition of these documents are available. For

undated references, the latest edition of the normative document referred to applies.

GB 713 steel plates for boilers (GB 713-1997, neq ISO 5832-4; 1996)

GB 3087 Seamless steel tubes for low and medium-pressure boiler(GB

3087-1999, neq ISO 9329-1; 1989)

GB/T 3274 Hot-rolled heavy plates and steel strips for carbon structure steel and

low-alloy structure steel

GB 5310 Seamless steel tubes and pipes for high-pressure boiler

GB/T 8163 Seamless steel tubes for liquid service (GB/T 8163-1999, neq ISO

559; 1991)

JB/T 6734 Strength calculation method for boiler fillet weld

Technical Supervision Regulation for Safety of Steam Boilers (issued by former

Department of Labor in 1996)

Technical Supervision Regulation for Safety of Hot-water Boiler (issued by

former Department of Labor in 1997)

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3 Terms and definitions

The following terms and definition are applicable to this standard.

3.1 Operating pressure

It refers to maximum pressure that pressure parts can bear up under normal working

condition.

3.2 Rated pressure

It refers to boiler name plate pressure or guaranteed outlet steam pressure when steam

boiler keeps long-term continuous operation under specified feed pressure and load

range.

3.3 Design pressure

It refers to pressure to ensure thickness of pressure parts.

3.4 Hydrostatic test pressure

It refers to pressure that pressure parts bear up under technical hydraulic test.

3.5 Design temperature

It refers to metallic wall temperature of pressure parts used to make sure elementary

permissible stress of steel products.

3.6 Corrosion allowance thickness

It refers to required additional thickness for reduction due to corrosion during

designed serviceable life for pressure parts.

3.7 Minus tolerance of thickness

It refers to minus tolerance of thickness

3.8 Processing thinning of thickness

It refers to thinning of thickness during manufacturing process of press pieces.

3.9 Theory thickness

Thickness of pressure parts required when theory computing formula is ensured.

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3.10 Minimum required thickness for production

Sum of theory thickness and corrosion allowance thickness

3.11 Design calculated thickness

It refers to thickness which is sum of minimum required thickness for production,

minus tolerance of thickness and processing thickness reduction value.

3.12 Nominal thickness

It is called "thickness" for short, refers to thickness selected after rounding design

calculated thickness to a certain standard specification of material, namely marked

thickness in drawing.

3.13 Effective thicknesses

It refers to thickness subtracting sum of corrosion allowance thickness, processing

thinning of thickness and minus tolerance of thickness from nominal thickness.

3.14 Component size

Except appointed especially, it refers to marked size of displayed drawing.

4 General provisions

Design, manufacture, installation, application, repair and reconstruction of pressure

parts for boiler calculated according to this standard shall meet " Technical

Supervision Regulation for Safety of Steam Boilers ", " Technical Supervision

Regulation for Safety of Hot-water Boiler "and related technical requirements and

standards for boiler-making.

For boiler whose parameter undulates greatly like peak-regulation load unit, it is also

required to conduct fatigue strength check (check for fatigue strength of boiler barrelshall be calculated according to appendix A).

5 Material, permissible stress and design temperature

Signification and unit of signs used in this chapter are as follows

5.1 Signs

b - Tensile strength when material is 20℃, MPa;

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s - Yield point or specified non-proportion elongation stress when material is 20℃

( 0.2 ), MPa;

t

s - Yield point or specified non-proportion elongation stress when material under

design temperature( t

0.2 ), MPa,

t

D - Long-time strength of material under design temperature for 105h, MPa;

5

- Extensibility when material is 20℃ and scale distance of sample is five times of

diameter, %;

][ - Permissible stress, MPa;

J][ - Elementary permissible stress, MPa;

bn - Safety factor corresponds to tensile strength;

sn - Safety factor corresponds to yield point or specified non-proportion elongation

stress;

Dn - Safety factor corresponds to long-time strength for 105h

- Compensation factor of elementary permissible stress;

bit - Design wall temperature℃;

Jt - Media rated mean temperature,℃;

bt - Media saturation temperature corresponds to design pressure (it refers to

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extracted water temperature of outlet for hot-water boiler),℃;

X - System for degree of media mixing;

t - Temperature deviation,℃

;

- Boiler barrel body, header tank body and ratio of outside diameter and inside

diameter of pipe

- Nominal thickness, mm;

- Heat transfer system of steel products, )m/(kW ℃ ;

maxq - Maximum heat flux density, 2m/kW ;

2 - Heat-transfer coefficient of internal wall to media, )m/(kW 2 ℃ ;

J - Flow equalization coefficient.

5.2 Material

5.2.1 Material of pressure parts for watertube boiler shall comply with GB 713, GB

3087, GB/T 3274, GB 5310, GB/T 8163 and provisions of related material purchases

standard of boiler industry. material unlisted in table 1 and table 2 of this standard

shall comply with relevant regulations of " Technical Supervision Regulation for

Safety of Steam Boilers "or" Technical Supervision Regulation for Safety of hot-water

boiler".

5.2.2 Plates used for manufacturing pressure parts of boiler shall possess favorable

plasticity, and their extensibility 5 shall be no less than 18%.

5.3 Permissible stress

5.3.1 it is required to calculate permissible stress according to formula (1):

][][ (1)

Elementary permissible stress shall be calculated according to the following formula

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and take minimum value:

b

bJ][

n

σ

≤ (2)

s

t

sJ][

n

σ

≤ (3)

D

t

DJ][

n

σ

≤ (4)

During calculation, b and t

s Shall be minimum guarantee value of steel products

(plates and tubular products) or statistic lower limit value of lots of test result;

t

D Shall be mean value of 105h long-time strength for of lots of test results for steel

products.

Value-taking of safety factor:

Elementary permissible stress ][ of usual boiler steel products in domestic shall

take values listed in Table 1 and Table 2.

5.3.2 If material not listed in table 1 and table 2 can comply with relevant regulations

in 5.2, its elementary permissible stress ][ shall be calculated according to formula

(2)~( 4), And take minimum value. During calculation, b , t

s and t

D shall take

minimum guarantee value of relevant steel grade: Sampling test for steel products

only can be used when there is no guarantee value, minimum value of b and t

s

as well as mean value of t

D for h105 got through the test shall be multiplied by

0.90 to be value for calculation. Sampling and test shall be conducted according to

relevant standard.

5.3.3 Service temperature of boiler low-carbon steel, low-carbon manganese steel and

low-carbon manganese vanadium steel is below 350℃; that of other low-alloy

refractory steel is below 400℃; and their elementary permissible stress only required

to be calculated according to formula (2) and (3), and it is unnecessary to consider

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formula (4).

5.3.4 If using overseas boiler steel products listed in appendix B and comply with

relevant regulations in 5.2, the elementary permissible stress can be selected

according to table B.1.

5.3.5 ][ between adjacent design temperature values in the table of elementary

permissible stress can be determined with arithmetic interpolation method; but it is

required to reject numbers follow the decimal point.

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Table 1 Elementary permissible stress of usual boiler tube under different design tem

steel grade and

number of

standard

10

GB 3087,

GB/T 8163

20

GB 3087,

GB/T 8163

20G

GB

5310

20MnG

GB

5310

25MnG

GB

5310

15MoG

GB

5310

20MoG

GB

5310

15Cr MoG

GB

5310

12Cr2MoG

GB

5310

12Cr1MoVG

GB

5310

12Cr2Mo

WVTiB

GB 5310

s 195 225 215 240 275 270 220 225 280 255 345

b 335 410 400 415 485 450 415 440 450 "0 540

20 124 145 148 153 180 167 147 150 167 163 200

250 104 125 125 132 151 116 125 148 124 156 168

260 101 123 123 131 150 115 124 147 124 155 168

270 98 120 120 130 148 114 123 146 124 154 168

280 96 118 118 128 147 112 123 145 124 153 168

290 93 115 115 127 145 112 122 144 124 152 168

300 91 113 113 125 144 111 121 143 124 151 168

310 89 111 111 124 142 110 121 141 124 149 168

320 87 109 109 123 140 109 120 140 124 148 168

330 85 106 106 121 138 108 119 138 124 146 168

340 83 102 102 ]20 137 ]07 118 136 124 144 167 350 80 100 100 115 135 106 118 135 124 143 167

360 78 97 97 112 130 106 117 132 124 141 167

Design

temperatur

e

bit /℃

370 76 95 95 108 127 105 116 132 124 140 166

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380 75 92 92 102 113 105 115 131 123 138 166

390 73 89 89 95 110 104 114 129 123 137 165

400 70 87 87 89 101 104 113 128 123 135 165

410 68 83 83 84 94 103 112 127 123 133 164

420 66 78 78 78 87 102 110 126 122 132 163

Table 1 (continue)

Steel grade and

number of

standard

10

GB

3087

,

GB/

T8163

20

GB

3087

,

GB/

T8163

20

G

GB

53

10

20M

nG

GB

5310

25M

nG

GB

5310

15M

oG

GB

5310

20M

oG

GB

5310

15CrM

oG

GB

5310

12Cr2

MoG

GB

5310

12Cr1M

oVG

GB 5310

12Cr2MoW

VTiB

GB 5310

12Cr3M

SiTiB

GB 531

s 195 225 21

5

240 275 270 220 225 280 255 345 440

b 335 410 40

0

415 485 450 415 440 450 470 540 610

430 61 75 75 73 8l 102 109 125 122 131 162 187

440 55 66 66 68 74 101 108 124 12l 130 161 186

Design

wall

temperatur

e

bit /℃ 450 49 57 57 62 67 100 107 123 116 128 160 185

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460 45 50 50 56 61 99 104 122 110 126 159 184

470 40 43 43 49 54 99 100 120 103 125 158 182

480 37 38 38 42 48 94 95 119 95 124 156 181

490 83 84 112 88 121 155 ]79

500 68 70 96 81 118 153 177

510 55 57 82 74 110 148 145

520 43 48 69 68 98 124 120

530 59 61 86 106 100

540 49 54 77 90 86

550 41 48 71 84 79

560 33 42 65 79 72

570 37 57 74 66

580 32 50 69 59

590 64 53

600 56 47

610

620

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630

640

650

660 670

680

Note 1: Data in parentheses is allowable stress values of steel pipe whose thickness is larger than 75 mm.

Note 2: Data below thick line is calculated according to long-time strength; temperature relevant to the data refers to temperature

has controlling influence to elementary permissible stress.

Note 3: Elementary permissible stress of steel casting shall take 0.70 times of relevant values listed in table 1.

Note 4: Value-taking for elementary permissible stress of wrought steel: it is allowed to use value of relevant steel grade in the table

allowed to use 0.90 times of value of relevant steel grade in the table when steel ingot is used to forge.

Table 2 elementary permissible stress of usual boiler plate under different design tem

Steel grade and

number of

standard

Q235

GB

3274

20g

GB 713

16 Mng

GB 713

19Mng

GB 713

22Mn

GB

713

Thickness of

steel plate/mm ≤60

>60

≤100≤36

>36

≤60

>60

≤100

>100

≤150≤60

>60

≤100

>100

≤150

s 235 225 205 305 285 265 245 335 315 295 27

b 375 400 390 470 470 440 440 510 490 480 51

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20 137 148 144 174 174 163 163 189 181 178 18

250 113 125 103 147 140 133 120 163 153 143 44

260 111 123 102 144 137 131 118 161 151 141 14

270 108 120 101 141 135 128 116 158 148 138 14280 105 118 99 139 132 125 114 155 145 135 14

290 103 115 98 136 129 123 112 153 143 133 14

300 101 113 97 133 127 120 110 150 140 130 14

310 111 96 132 125 119 109 147 137 127 14

320 109 95 131 124 117 107 145 135 125 14

330 106 94 129 123 116 106 142 132 122 14

340 102 93 128 121 115 105 139 129 119 14

350 100 92 127 120 113 103 137 127 117 14

360 97 91 125 119 112 102 133 123 114 13370 95 90 124 117 111 101 129 120 111 13

380 92 89 122 116 109 99 125 117 109 12

390 89 88 120 115 108 98 121 113 106 11

400 87 85 117 113 107 97 117 110 103 10

410 83 77

420 78 69

430 75 62

440 66 55

design

temper

ature

bit /℃

450 57 49

Note 1: Data under thick line shall be calculated as long-time strength t

D , temperature corresponds to this data refers to te

steel grade has controlling influence to elementary permissible stress.

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Note 2: Value-taking for elementary permissible stress of wrought steel: It is allowed to use value of relevant steel grade in th

forge; it is allowed to use 0.90 times of value of relevant steel grade in the table when steel ingot is used to forge.

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5.3.6 Compensation factor shall be taken in accordance with component structural

feature and working conditions according to Table 3.

5.4 Design wall temperature

5.4.1 design temperature shall be maximum value of arithmetic mean value of inside

and outside wall temperature for pressure parts.

When determine design temperature, undulation in allowed band of steam-gas

temperature at boiler outlet shall be excluded from consideration.

When design temperature of pressure parts is below 250℃, it shall take 250℃.

5.4.2 Design wall temperature of pressure parts can be selected according to table 4~6

or calculated according to formulae in 5.4.3.

Table 3 Compensation factor of elementary permissible stress

Component type Working conditions

Non- heating (out of flue or insulated) 1.00

Heating (smoke temperature is no larger than 600℃)

or boiler barrel whose radiant heat flux permeating

pipe bundle is not large, as well as wall surfaces ofits barrel body are free from intensive wash of fume

0.95

Boiler barrel and

header tank body

Heating (smoke temperature is larger than 600℃) 0.90

Pipe (including pipe

head) and conduit of

boiler scope

1.00

Convex head 1.00

Flat-end cover Refer to table 17

Cover board 1.00

Non- heating (out of flue or insulated) 1.00

Heating (smoke temperature is no larger than 600℃) 0.95

Odd component

Heating (smoke temperature is larger than 600℃) 0.90

Note: For boiler barrel and end socket whose rated pressure is no less than 16.7 MPa, value

shall take 0.95

Table 4 Design wall temperature of boiler barrel bit

Unit is degree centigrade

Working conditions Computing formula

Non- heating Out of flueJ bi t t

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Insulated In flue

In hearth10J bi t t

40J bi t t

Radiant heat flux permeating pipe bundle is not large and wallsurfaces of barrel body are free from intensive wash of fume

20J bi t t

Non-heat-insulated In convection pass where smoke

temperature is less than 600℃

In convection pass where smoke

temperature is 600℃~900℃

In convection pass or hearth where smoke

temperature above 900℃

30J bi t t

50J bi t t

90J bi t t

Note 1: For heated boiler barrel, computing formula offered by this table refers to heating

condition of water space.

Note 2: When media is saturation temperature, bJ t t .

Table 5 Design wall temperature of header tank and anti-scorching tank bit


Content media Working conditions Computing formula

Out of flue (without heating)J bi t t

In flue, taking heat-insulated measures to prevent directaction of radiation and burning

10J bi t t

In convection pass where smoke temperature is less than

600℃, non-heat-insulated30J bi t t

In convection pass where smoke temperature is

800℃~900℃, non-heat-insulated50J bi t t

Water or steam-water

mixture

In hearth, non-heat-insulated110J bi t t

Out of flue (without heating)bt t bi

Saturated steam

In flue, taking heat-insulated measures to prevent direct

action of radiation and burning25 b bi t t


600℃, non-heat-insulated40 b bi t t

Saturated steam


600℃~900℃, non-heat-insulated60 b bi t t

Steam-gas Out of flue (without heating)t X t t J bi

In flue, taking heat-insulated measures to prevent direct

action of radiation and combustion productt X t t 25

J bi

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600℃, non-heat-insulatedt X t t 40J bi


600℃~900℃, non-heat-insulatedt X t t 60J bi

Note: For heated steam-water mixture header tank and anti-scorching tank body, computing formulae showed inthis table refer to condition without free water surface.

5.4.3 Determine design temperature with computing formula:

Boiler barrel:

11000

max

2

max b bi

qqt t (6)

Header tank:

t X qq

t t

11000

max

2

maxJ bi

(7)

Pipe:

t qqt t

)11000

J( max

2

maxJ bi

(8)

Table 6 Design wall temperature of pipe and conduit bit


Component Condition Computing formula

Rated pressure of boiler is no larger than 13.7 MPa

and maxq is no larger than 2m/kW407

60 b bi t t Boiling

tube

Other conditions Formula (8)

Coal

economizer

Convection-type coal economizer30J bi t t

Rayonnant coal economizer60J bi t t

All conditions Formula (8)

Convection type superheater50J bi t t

Superheater

No heat

calculation

document Rayonnant or semi rayonnant

(screen type) superheater

100J bi t t

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Conduit Out of flue (without heating)J bi t t

5.4.4 t X qt t 、、、、 max bJ and J in table 4 ~ table 6 and formula (6)~formula (8) It is

required to take values determined in boiler heat calculation and hydrodynamic force

calculation, thereinto:

Temperature deviation t , It must no less than 10℃ at any moment;

Coefficient of media mixing degree X, it usually is 0.50 for header tank; It is

permissible to take 0 when media enters from header tank tip; For non- heating

steam-gas header tank, even if perfect mixing, it is required to take ℃10t X ;

Coefficient of heat conductivity Shall be taken according to relevant handbooks.

6 Boiler barrel body

6.1 Signs


L - Theory thickness of boiler barrel body, mm;

min - Minimum required thickness for production of boiler barrel body, mm;

s - Design calculated thickness of boiler barrel body, mm;

- Nominal thickness of boiler barrel body, mm;

y - Effective thickness of boiler barrel body, mm;

l - Nominal thickness of pipe head, mm;

C - Consider reduction due to corrosion, processing reduction and additional thickness

of minus tolerance of steel plate thickness, mm;

1C - Consider additional thickness of reduction due to corrosion, mm;

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2C - Consider additional thickness of processing reduction, mm;


n D - Inside diameter of boiler barrel body, mm;

wd - Outside diameter of pipe head, mm;

L - Figure out ratio of outside diameter and inside diameter according to theory

thickness of boiler barrel body;

- Figure out ratio of outside diameter and inside diameter according to effective

thickness of boiler barrel body;

p - Design pressure, MPa;

][ p - Maximum permissible design pressure of check calculation, MPa;

p g - Operating pressure, MPa;

e p - Rated pressure of boiler, MPa;

a p - Design supplementary pressure, MPa;

z p - Supplementary pressure of media flow resistance, MPa;

sz p - Liquid column static pressure that computing element suffers, MPa;

sw p - Hydrostatic test pressure, MPa;

][ sw p - Maximum allowable pressure of hydraulic test, MPa;

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][ - Permissible stress of boiler barrel body material, MPa;

]][ - Permissible stress of pipe head material, MPa;

s - Yield point or specified non-proportion elongation stress when material is

20℃( 2.0 ), MPa;

- Attenuation coefficient of longitudinal pore bridge;

- Attenuation coefficient of transverse pore bridge;

- Attenuation coefficient of oblique pore bridge;

d - Equivalent attenuation coefficient of oblique pore bridge;

h - Attenuation coefficient of welded seam;

min - Minimum attenuation coefficient;

][ - Permissible minimum attenuation coefficient;

J - Attenuation coefficient of check position;

SW - Minimum attenuation coefficient during hydraulic test;

K - Reduction coefficient for oblique pore bridge;

os - Minimum pitch between two adjacent pores without regard for hole-by-hole

influence, mm;

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s - Pitch between two adjacent longitudinal (axial) pores, mm;

s - Pitch between two adjacent transverse (hoop stress) pores, mm;

s - Pitch between two adjacent pores along oblique direction, mm;

d - Initial pore diameter, size of elliptical pore at direction of relevant pitch; inside

diameter and rated pressure of push-in type integral welding pipe head shall be

no larger than inside diameter of push-in type double fillet welding pipe head

(pore circle) on non- heating boiler barrel of 2.5 MPa, mm;

a - Arc length between two pores at direction of barrel body's mean diameter circle

when calculate attenuation coefficient of oblique pore bridge, mm;

b - Distance between two pores at barrel body's axial direction when calculateattenuation coefficient of oblique pore bridge, mm;

n - Ratio of distance b between two pores at barrel body's axial direction to arc length

between two pores at direction of barrel body's mean diameter circle;

- Angle of pore centerline deflects radial direction of barrel body, (°);

dd - Equivalent diameter of pore, mm;

pd - Diametric mean value of two adjacent pores, mm;

w - Skin bending stress of checking profile, MPa;

M - Bending moment of checking profile, kN·mm;

W - Bending resistance section factor of checking profile mm3.

6.2 Computing formula

6.2.1 it is required to calculate theory thickness of boiler barrel body according to

formula (9):

p

pD

-)(2 min

nL

(9)

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Minimum required thickness for production of boiler barrel body shall be calculated

according to formula(10):

1min C L (10)

It is required to calculate design calculated thickness of boiler barrel body according

to formula (11):

C L s (11)

Nominal thickness of boiler barrel body shall satisfy:

s ≥

6.2.2 Permissible minimum attenuation coefficient of boiler barrel body shall be

calculated according to formula(12):

y

yn

]2[

)(][

D p (12)

y calculate according to (13):

y (13)

y value also can be taken by using actual minimum thickness of barrel body to

subtract reduction value due to corrosion.

6.2.3 During check calculation, maximum permissible design pressure of boiler barrel

body shall be calculated according to formula (14):

yn

y][2][

D p (14)

Effective thickness in formula (14) shall be calculated according to formula (13), at

that time, minJ ; y Can be taken by using actual minimum thickness of J to

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subtract reduction value due to corrosion, then, )/()( ynyJ D in formula (14)

shall adopt minimum value. Furthermore, maximum permissible design pressure of

boiler barrel body calculated with formula (14) shall satisfy requirements of open pore

reinforcement in chapter 11.

6.26.4 Scope of application of formula (9), (12) and (14) is 30.1L≤ , L Value shall

be calculated according to formula (15):

n

LL 21

D

(15)

6.3 Design pressure and operating pressure

It is required to calculate 'design pressure of boiler barrel body according to formula

(16):

ag p p p (16)

operating pressure g shall be calculated according to formula (17):

szzeg p p p p (17)

z Take pressure drop between computing element and boiler exit during maximum

discharge.

When liquid column static pressure that boiler barrel body beard is no larger than 3%

of )( zae p p p 3%, it is required to take 0sz p .

Design supplementary pressure a p can be calculated according to the following

provisions:

a) MPa03.0a p ; MPa8.0e≤ p when

b) when MPa9.5MPa8.0 e≤≤ p , ca 04.0 p ;

c) when MPa9.5e＞ p , ea 50.0 p p .

6.4 Attenuation coefficient

6.4.1 Minimum attenuation coefficient in formula (9) min Shall take minimum value

among attenuation coefficient of longitudinal seam h , Attenuation coefficient of

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longitudinal pore bridge , Two times of attenuation coefficient of transverse pore

bridge '2 , and equivalent attenuation coefficient of oblique pore bridge d . If pore

bridge locates at welded seam, it shall be used according to relevant regulations of6.10.2 and 6.10.3.

6.4.2 For welded seam certificated according to boiler-making technical requirements,

Its attenuation coefficient of welded seam h can be taken according to table 7.

Table 7 Attenuation coefficient of welded seam h

Welding method Type of welded seamh

Both sides welded groove-butt weld 1.00

One side welded groove-butt weld underlay with argon arc

welding

0.90

One side welding groove-butt weld underlay without argon

arc welding

0.75

Manual arc welding

One side welded groove-butt weld which has backing

board or gasket at root of welded seam

0.80

Both sides welded groove-butt weld 1.00

One side welded groove-butt weld 0.85

Automatic welding

under fluxing agent

layer One side welding plain butt weld 0.80

Electroslag welding 1.00

Note: Under the condition of that elementary permissible stress is determined as long-time

strength, for welding in table 80.0h , h shall take 0.80.

6.4.3 Diameter of two adjacent holes shall be no larger than maximum permissible

diameter of non reinforced opening determined according to 11.2.3, and pitch between

two holes (longitudinal, transverse or oblique) is less than value calculated according

to formula (18), it is required to calculate attenuation coefficient of pore bridge

according to 6.4.5 ~ 6.4.13.

)(2 n p0 Dd s (18)

pd of the formula can be calculated according to formula (24).

6.4.4 If diameter of single-hole or diameter of a hole in two adjacent holes is larger

than maximum permissible diameter of non reinforced opening determined in 11.2.3,

it is required to treat according to relevant regulations of chapter 11.

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64.5 Hole-bridge attenuation coefficient of longitudinal two adjacent holes (figure 1)

of equal diameter shall be calculated according to formula (19):

s

d s - (19)

6.4.6 Hole-bridge attenuation coefficient of transverse two adjacent holes (figure 2) of

equal diameter shall be calculated according to formula (20):

s

d s

Transverse pitch s in this formula shall take Arc length on barrel body mean

diameter circle.

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6.4.7 Hole-bridge attenuation coefficient of oblique two adjacent holes (figure 3) of

equal diameter shall be calculated according to formula (21):

K d (21)

In this formula, reduction coefficient K for oblique pore bridge shall be calculated

according to formula (22):

22 )n1/(75.01

1

K (22)

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Attenuation coefficient of oblique pore bridge shall be calculated according to

formula (23):

s

d s

(23)

Where: 21 na s .

When n≥2.4, it is allowable to take K =1, then d .

When 1d＞ , take 00.1d .

d Also can be directly selected according to alignment chart (figure 4), where

)2/()( 21 ad d N , Broken-line in the figure is connection of minimum value of

each curve.

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6.4.8 If diameter of two adjacent holes are different, when calculate pore bridge

attenuation coefficient Diameter d in formula (19), (20) and (23) shall adopt mean

value of diameters of two adjacent holes pd , and pd shall be calculated according to

formula (24):

2

21 p

d d d

(24)

21 ,d d in this formula are diameters of two adjacent holes (or equivalent pore

diameter).

6.4.9 Open pore with recess (figure 5), When calculate pore bridge attenuation

coefficient, Diameter d in formula (19), (20) and (23) shall adopt equivalent diameter

dd ; and equivalent diameter can be calculated according to formula (25):

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)( 111d d d h

d d

(25)

For other echelon form pores with faulty fusion welding besides figure 5, their

equivalent diameter is equal to the value using longitudinal section area of echelon

form pore (except part filling with weld metal) divided by nominal thickness of barrel

body.

6.4.10 For non-radial hole on cross section of barrel body (figure 6), when calculate

pore bridge attenuation coefficient, Diameter d in formula (19), (20) and (23) shall

adopt equivalent diameter dd ; and equivalent diameter dd can be determined

according to following principles:

Longitudinal pore bridge:

d d d

Transverse pore bridge:

cosd

d d

Oblique pore bridge:

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22

2

dcos

1

n

nd d (26)

Whereα

shall be no larger than 45°.

Non- radial hole shall be formed through mechanical processing or shape cutting.

6.4.11 For elliptical hole, pore diameter d shall be determined according to size of this

hole along the direction of relevant pitch when calculate pore bridge attenuation

coefficient.

6.4.12 for push-in type integral welding pipe head or push-in type double fillet weld

pipe head (or hole circle) on non- heating boiler barrel whose rated pressure is no

larger than 2.5 MPa, when permissible stress of pipe head (or hole circle) material

1

][ is less than permissible stress of barrel body material ][ , d in attenuation

coefficient calculation shall take sum of inside diameter of pipe head (or hole circle)

and ])]/[]([[12 11 － .

6.4.13 Hole bridge attenuation coefficient can be improved by dint of strengthening

action of excess thickness of welded construction's pipe head; refer to 11.5.2 ~ 11.5.4

for reinforcement method.

6.5 Additional thickness

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6.5.1 Additional thickness of boiler barrel body C can be calculated according to

formula (27):

321 C C C C (27)

6.5.2 It is required to consider that additional thickness of reduction due to corrosion

1C usually take 0.5 mm. If mm20＞ , there is no need to consider. but if corrosion

is severe, it is required to determine 1C value according to practical situation.

6.5.3 Consider additional thickness of processing reduction 2C And take value

according to practical situation of each manufacturer. When plate thickness is nolarger than 100 mm, it is allowed to select according to table 8 in general.

Table 8 Reduction value due to rolling technology

Unit is millimeter

Rolling technology Reduction value

)MPa8.9(4 c≥ p Hot rolling

)MPa8.9(4 e＜ p

Hot sizing 1Cold rolling

Cold sizing 0

6.5.4 Consider additional thickness of steel products' minus tolerance of thickness C,

when mm20≤ , Take minus tolerance of steel products' standard nominal

thickness; when mm20＞ , There is no need to consider that, If steel products'

minus tolerance of thickness exceeds 0.5 mm, It is required to add the excess value to

additional thickness.

6.6 Limit to thickness

6.6.1 Nominal thickness of boiler barrel body is required to be no less than 6 mm in

any case; when connect with expanded joint pipe, nominal thickness of boiler barrel

body shall be no less than 12 mm.

6.6.2 Non-heat-insulated boiler barrel body that rated pressure of boiler is no largerthan 2.5 MPa is allowed to be put into flue or hearth where smoke temperature is no

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less than 600℃, and its thickness shall be no larger than specified value in table 9.

Table 9 Maximum permissible thickness of non-heat-insulated boiler barrel body

Unit is millimeter

Working conditions Maximum permissible thickness

In flue or hearth where smoke temperature is larger than

900℃

26

In flue where smoke temperature is 600℃~900℃ 30

6.7 Hydraulic test

Hydrostatic test pressure of boiler barrel body sw p Shall be taken according to

relevant boiler-making technical requirements based on satisfying requirement of

formula (28):

][ swsw p p ≤ (28)

Maximum allowable pressure of hydrostatic test shall be calculated according toformula (29):

ssw2

2

sw

145.0] p[

(29)

Where,

ny /21 D .

sw shall take the minimum one of attenuation coefficient of longitudinal seam of

boiler barrel body h , Attenuation coefficient of longitudinal pore bridge , Two

times of attenuation coefficient of transverse pore bridge '2 And equivalent

attenuation coefficient of oblique pore bridge d .

When determine maximum allowable pressure of boiler barrel for hydrostatic test, it is

required to consider maximum allowable pressure of boiler barrel's end socket for

hydrostatic test (refer to 9.2.11).

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6.8 Check for bending stress

6.8.1 When spacing between supporting points of boiler barrel body is larger than 10

m or '2 is not larger than minimum or d , It is required to conduct check for

bending stress causes by gravity load.

6.8.2 Maximum bending stress of checking profile of boiler barrel body shall be

calculated according to formula (30):

hW

M

0001w (30)

Bending moment of checking profile M shall be treated as freely supported beam. If

there is no relatively large partial load, load on beam can be considered as equispaced

load. Load that may cause bending moment shall include: metal weight of boiler

barrel and conjoint component, water weight when boiler barrel and conjoint

component are full filled with water as well as weight of insulant etc.

When calculate bending resistance section factor W of checking profile, it is required

to consider reduction of cross section due to open pore. refer to appendix C for

proximate calculation method for W.

Attenuation coefficient of ring welded seam h , It shall be only taken into

consideration when there is ring welded seam on checking profile. h shall be taken

according to table 7.

If maximum bending moment and minimum bending resistance section factor of

barrel body are not on the same cross section, it is required to respectively calculate

according to several cross sections where danger may occur so as to find out

maximum bending stress of whole barrel body.

6.8.3 Maximum bending stress got through 6.8.2 shall satisfy the following condition:

y

yn

w4

)(][

x

D p －≤ (31)

Attenuation coefficient x Is attenuation coefficient of transverse pore bridge or

attenuation coefficient of ring welded seam on location of maximum bending stress

on checked profile; If transverse pore bridge and ring welded seam overlaps, it is

required to deal with according to 6.10.2 and 6.10.3; If there is no hole-bridge or

welded seam weakens at this location, then 1 x .

6.9 Calculation for boiler barrel body of equal pitch diameter but unequal

thickness

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Strength of thin wall and thick-wall shall be respectively calculated according to

formula (9) ~ (31). In upsaid formula, nD shall respectively use n R2

and n R 2.

(Figure7).

Maximum allowable pressure of hydraulic test shall take smaller value of calculatedvalue according to formula (29).

6.10 Structural requirement

6.10.1 Difference between maximum and minimum inside diameter of same cross

section of boiler barrel body shall be no larger than specified value of table 10.

Table 10 Difference between maximum and minimum inside diameter of same

cross section of boiler barrel body

Unit is millimeter

Condition MPa8.3c≤

p

MPa8.3e＞

p

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mm0001n≤ D

m5001mm0001 n≤≤ D

mm5001n＞ D

10.1L＜ 10.1L≥

Hot rolling 6 7 9

Cold rolling 4 6 8

nD007.0 nD010.0

6.10.2 For expanded joint pore, pore bridge attenuation coefficient , and

shall be no less than 0.30. Expanded joint pore shall satisfy Requirements of

"Technical Supervision Regulation for Safety of Steam Boilers". When expanded joint

pore locates at ring seam, attenuation coefficient of this location shall take arithmetic

product of pore bridge attenuation coefficient and attenuation coefficient of welded

seam.

6.10.3 pores centralize on down pipe should not be made in welded seam. other

welding pores should not be made in welded seam, it is required to satisfy

requirements of "Technical Supervision Regulation for Safety of Steam Boilers" if it

can't be avoided. Then attenuation coefficient of the location shall take arithmetic

product of pore bridge attenuation coefficient and attenuation coefficient of welded

seam.

6.10.4 Nominal thickness of pipe head (except pipes used to connect heating surface)

)2

1 Shall be no less than mm2.3015.0 w d for boiler whose rated steam pressure

larger than 2.5 MPa.

6.10.5 Transition zone for boiler barrel body of unequal thickness shall satisfy

requirements of figure 8, Among which pitch of gradient should not exceed 1:4, and it

is forbidden to open pores at region of a to bb .

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Figure 8 Requirements for Transition Interval

2) If pipe head is spiral, thickness shall be taken from root of spiral burr.

7 Cylindrical header tank body

7.1 Signs


L - Theory thickness of header tank body, mm;

min - Minimum required thickness for production of straight header tank body, mm;

s - Design calculated thickness of header tank body, mm;

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- Nominal thickness of header tank body, mm;

y - Effective thickness of header tank body, mm;

C - Design calculation shall consider reduction due to corrosion, processing reduction

and additional thickness of minus tolerance of steel pipe thickness, mm;

C - Check calculation shall consider reduction due to corrosion, processing

reduction and additional thickness of minus tolerance of steel pipe thickness, mm;

1C - Design calculation and check calculation shall consider additional thickness of

reduction due to corrosion, mm;

2C - Design calculation shall consider additional thickness of processing reduction,

mm;

2C - Check calculation shall consider additional thickness of processing reduction,

mm;

3C - Design calculation shall consider additional thickness of minus tolerance of

steel pipe thickness, mm;

3C - Check calculation shall consider additional thickness of minus tolerance of steel

pipe thickness, mm;

W D - Outside diameter of header tank body, mm;

L - Ratio of outside diameter and inside diameter worked out according to theory

thickness of header tank body;

- Ratio of outside diameter and inside diameter worked out according to effective

thickness of header tank body;


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][ sw p - Maximum allowable pressure of hydrostatic test, MPa;



J - Attenuation coefficient of check position;

min - Minimum attenuation coefficient;


R - Semidiameter of central line of circular arc header tank, mm;

w - Additional bending stress of checking profile MPa;

m - Percentage of steel pipe minus tolerance of thickness and nominal thickness;

n - Ratio between semidiameter of circular arc header tank's central line R and outside

diameter of header tank body w D .


7.2.1 Theory thickness of header tank body shall be calculated according to formula

(32):

p

pD

][2 min

wL (32)

Minimum required thickness for production of straight header tank body shall be


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2Lmin C (33)

Design calculated thickness of header tank body shall be calculated according to

formula (34):

CL (34)

Nominal thickness of header tank body shall satisfy:

s≥

7.2.2 Permissible minimum attenuation coefficient of header tank body shall becalculated according to formula (35):

y

yw

][2

)][

－（ D p

(35)

y Shall be calculated according to formula (36):

Cy (36)

7.2.3 During check calculation, maximum permissible design pressure of header tank

body shall be calculated according to formula (37):

yw

yJ ][2

][

D p (37)

Effective thickness y in formula (37)Shall be calculated according to formula (36),

then minJ ; y of straight header tank body can be taken by subtracting

reduction value due to corrosion from actual minimum thickness at each J , then,

)/()( ywyJ D in formula (37) shall use minimum value. Furthermore, maximum

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permissible design pressure of header tank body calculated with formula (37) shall

satisfy requirements of open pore reinforcement in chapter 11.

7.2.4 Scope of application of formula (32),(35) and (37) are as follows:

For header tank body of water, steam-water mixture or saturated steam: 50.1L≤

For header tank body of steam-gas: 00.2L≤

L value shall be calculated according to formula (38):

Lw

wL

2

D

D (38)


Design pressure and operating pressure of header tank body shall be calculated

according to provisions of 6.3.

For header tank body of reheat steam, design pressure p shall take 1.15 times of media

operating pressure in reheat steam header tank when it is rated pressure.


Attenuation coefficient of header tank body shall be determined according to 6.4.

7.5 Additional thicknesses during design calculation

7.5.1 Additional thickness C of header tank body can be calculated according to

formula (39):

321 CCCC (39)

7.5.2 Considering that additional thickness of reduction due to corrosion 1C usually

take 0.5 mm, During design operating period of header tank, if reduction due to

corrosion exceeds 0.5 mm, then it is required to take actual reduction value.

7.5.3 for straight header tank body made of steel pipe, if considering the additional

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thickness of processing reduction, 02 C ; if considering 3C additional thickness for

minus tolerance of steel pipe thickness, it is required to calculate with formula (40):

)(100

1L3 C m

mC (40)

For arcs header tank body made from steel pipe, considering the additional thickness

of processing reduction 2C and considering additional thickness for minus tolerance

of steel pipe thickness 3C shall be respectively calculated according to formula (41)

and formula (42):

1)1)(2-(4

L2

nn

C

(41)

)(100

21L3 C C m

mC

(42)

7.6 Additional thickness during check calculation

7.6.1 Additional thickness of header tank body 'C shall be calculated according to

formula (43):

321 ''' C C C C (43)

7.6.2 Considering additional thickness of reduction due to corrosion 1C shall be

selected according to provision 7.5.2 .

7.6.3 For straight header tank body made from steel pipe, 0'2 C when considering

additional thickness of processing reduction; Considering additional thickness for

minus tolerance of steel pipe thickness 3'C , it is required to calculate with formula

(44):

100

'3m

C (44)

For arc header tank body made from steel pipe, it is required to determine according

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to formula (44) if considering additional thickness for minus tolerance of steel pipe

thickness 3C . It is required to determine according to formula (45) if Considering

additional thickness of processing reduction 2'C :

)14(2

'C－C－' 312

nn

C

(45)


7.7.1 for boiler whose rated pressure is larger than 2.5 MPa, thickness of

non-heat-insulated header tank body shall be no larger than specified value in table

11.

Table 11 Maximum permissible thickness for non-heat-insulated header tank

body

Unit is millimeter

Working conditions Maximum permissible wall thickness

In flue or hearth where smoketemperature is larger than 900℃

In flue where smoke temperature is

600℃~900℃

30

45

3) For arc header tank body whose 5.3/ w＞ D R , Except that maximum permissible

degree of roundness for cross section is required to satisfy requirements in table 13,

the rest shall be treated as straight header tank.

7.7.2 For boiler whose rated pressure is no larger than 2.5 MPa, thickness of

non-heat-insulated header tank and anti-scorching tank body shall be no larger than

specified value in table 12.

Table 12 Maximum permissible thickness for non-heat-insulated header tank and

anti-scorching tank body

unit is millimeter

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Working conditions Maximum permissible wall thickness

In flue or hearth where smoke temperature is

larger than 900℃

In flue where smoke temperature is

600℃~900℃

15

20

7.8 Hydraulic test

Hydrostatic test pressure sw p of header tank body shall be taken according to

relevant boiler-making technical requirements based on satisfying requirement of

formula (28):

][ swsw p p ≤

][ sw p shall be determined according to formula (29), in the formula during the

calculation shall be calculated according to formula (46):

yw

w

2

D D (46)

When determine maximum allowable pressure of hydrostatic test for header tank, it is

required to consider maximum allowable pressure of hydrostatic test for end socket,

flat-end cover or cover board of header tank. (refer to 9.2.11, 10.2.6 and 10.3.8).

7.9 Check for bending stress

For header tank with larger gravity load, it is required to conduct check calculation for bending stress according to formula (47):

)(4

)2(][

ywyx

2

yw

w

D

D p≤ (47)

Values w and x shall be dealt with according to provisions of 6.8.2 and 6.8.3.

7.10 Structural requirement

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7.10.1 roundness of cross section of arc header tank made from steel pipe should be

larger than specified value in table 13.

Table 13 Maximum permissible roundness of cross section of arc header tank

Expressed with %

Bending radius

Rww 0.45.2 D R D ≤≤ w0.4 D R＞

roundness

100w

minwmaxw

D

D D

10 5

Note: maxw D and minw D Respectively is the maximum and minimum outside diameter of the

same cross section.

7.10.2 Refer to 6.10.2 and 6.10.3. for requirements of attenuation coefficient and pore

position

7.10.3 Nominal thickness of pipe head (except pipes used to connect heating surface)

shall be dealt according to 6.10.4.

8 Pipe and conduit in range of boiler

8.1 Signs


L - Theory thickness of straight pipe or straight conduit, mm;

Lw - Theory thickness for outside of angle branch, mm;

min - Minimum required thickness of straight pipe or straight conduit production,

mm;

minw - Minimum required thickness for outside of angle branch production, mm;

s - Design calculated thickness of straight pipe or straight conduit, mm;

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sw - Design calculated thickness of angle branch, mm;

- Nominal thickness of pipe or conduit, mm;

y - Effective thickness of straight pipe or straight conduit, mm;

wy - Effective thickness of outside of angle branch, mm;

C - Design calculation shall consider reduction due to corrosion, processing reduction

and additional thickness of minus tolerance of steel pipe or steel plate thickness, mm;

C - Check calculation shall consider reduction due to corrosion, processing reductionand additional thickness of minus tolerance of steel pipe or steel plate thickness. mm;



2C - Design calculation shall consider additional thickness of processing reduction,

mm;

2C - Check calculation shall consider additional thickness of processing reduction,

mm;

3C - Design calculation shall consider additional thickness of minus tolerance of

steel pipe or steel plate thickness, mm;

3C - Check calculation shall consider additional thickness of minus tolerance of steel

pipe or steel plate thickness, mm;

w D - Outside diameter of pipe or conduit, mm;

L - Ratio of outside diameter and inside diameter calculated according to theory

thickness of pipe or conduit;

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[ p] - Maximum permissible design pressure for check calculation of straight pipe or

straight conduit, MPa;

w p][ - Maximum permissible design pressure of check calculation for angle branch,

MPa;



R - Semidiameter of angle branch's central line, mm;

maxq - Maximum heat flux density, 2kW/m ;

- Coefficient of heat conductivity of steel products )m/(kW ℃ ;

z - Additional axial stress of checking profile MPa;

w - Additional bending stress of checking profile, MPa;

- Additional distorting stress of checking profile, MPa;

F - Additional axial force, kN;

M - Bending moment of checking profile mmkN ;

n M - Twisting moment of checking profile mmkN ;

A - Area of pipe's effective cross section, 2mm ;

W - Effective bending resistance section factor of checking profile,3

mm ;

m - Percentage of steel pipe minus tolerance of thickness and nominal thickness

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K - Angle branch's shape factor;

a - Angle branch's technological coefficient;

b - Reduction rate of actual manufacturing process for angle branch's outsidethickness;

1 A - Coefficient.


8.2.1 Theory thickness of straight pipe or straight conduit shall be calculated


p

pDw

][2 h

L (48)

Angle branch is bended from steel pipe; theory thickness of angle branch outside shall


LwL K (49)

Where, angle branch's shape factor K shall be calculated according to formula (50):

w

w

24

4

D R

D R K

(50)

Thickness of casting angle branch and welding angle branch compressed with steel

plate shall be calculated as straight pipe

Minimum required thickness of straight pipe or straight conduit production shall be


1Lmin C (51)

Angle branch is bended from steel pipe; minimum required thickness of angle branch

production outside shall be calculated according to formula (52):

1wLmin C w (52)

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52

Design thickness of straight pipe or straight conduit shall be calculated according to

formula (53):

C s L (53)

Angle branch is bended from steel pipe; design thickness of angle branch shall be


C w sw L

(54)

Nominal thickness of straight pipe or straight conduit shall satisfy:

s≥

Angle branch is bended from steel pipe; nominal thickness of angle branch shall

satisfy:

ws≥

Welding angle branch )5.3/( ＞w D R compressed with steel plate, But additional

thickness C shall be respectively calculated according to formula (60) and (61): .

8.2.2 During check calculation, maximum permissible design pressure of straight pipe

or straight conduit shall be calculated according to formula (55):

yw

yh ][2][

D p (55)

y shall be calculated according to formula (56):

Cy － (56)

y value can be taken by using actual minimum thickness to subtract reduction value

due to corrosion.

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53

Maximum permissible design pressure of angle branch shall be calculated according

to formula (57):

yw

ywh

wwK

][2][

D p (57)

wy shall be calculated according to formula (58):

C wy (58)

Maximum permissible design pressure of pipe or conduit with angle branch shall

smaller value between formula (55) and formula (57).

8.2.3 formulae (48), (49),(55) and (57) are applicable in range of 00.2L≤ , L

value shall be calculated according to formula (38).


Design pressure and operating pressure of pipe or conduit shall be calculated

according to provisions of 6.3.

For pipe or conduit of reheat steam, design pressure shall take 1.15 times of media

operating pressure in pipe or conduit when it is rated pressure.


Attenuation coefficient of welded seam h ; it shall take 1.00 for seamless steel tube;

it shall be taken according to table 7 for welding angle branch compressed with steel

plate.

8.5 Additional thickness during design calculation

8.5.1 Additional thickness C of straight pipe or straight conduit shall be calculated

according to formula (59);

31 C C C (59)

Angle branch bended with steel pipe and welding angle branch compressed with steel

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54

plate )5.3/( ＞w D R , Additional thickness C of angle branch can be calculated


321 C C C C (60)

Additional thickness C of casting angle branch shall be calculated according to

formula (61):

2L1 AC (61)

1

A in the formula shall be calculated according to formula (62):

2)/(4

11

w D R

A (62)

8.5.2 Consider additional thickness of reduction due to corrosion 1C shall be

selected according to provisions of 7.5.2.

8.5.3 Angle branch bended with steel pipe ,Considering additional thickness of

processing reduction 2C shall be calculated according to formula (63):

)(100

1wL2 C a

aC

(63)

a in the formula shall be calculated according to formula (64):

R Da w25 (64)

When b - actual processing reduction rate of angle branch outside is larger than

calculated value a, a value shall take actual processing reduction rate of angle branch

outside thickness.

Welding angle branch compressed with steel plate )5.3/( ＞w D R , 2C Take actual

processing reduction value during compressing steel plate.

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8.5.4 Straight pipe or straight conduit, consider additional thickness of minus

tolerance of steel pipe thickness 3C shall be calculated according to formula (65);

)(100

1L3 C m

mC (65)

Angle branch bended with steel pipe , Consider additional thickness of minus

tolerance of steel pipe thickness 3C shall be calculated according to formula (66):

)(100

21wL3 C C m

mC

(66)

Welding angle branch compressed with steel plate )5.3/( ＞w D R , Consider additional

thickness of reduction due to corrosion 3C Can be determined in accordance with

provisions of 6.5.4, and also can take actual thickness variation of steel plate.

8.6 Additional thickness during check calculation

8.6.1 Additional thickness of straight pipe or straight conduit 'C shall be calculated


31 C C C (67)

Angle branch bended with steel pipe and welding angle branch compressed with steel

plate )5.3/( ＞w D R , Additional thickness of bend 'C shall be calculated according to

formula (68):

1

1

1

2

A

AC

(68)

Additional thickness of casting angle branch C’ shall be calculated according to

formula (69):

1

1

1

2'

A

AC

(69)

1 A in the formula shall be determined according to formula (62).

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56

8.6.2 Consider additional thickness of reduction due to corrosion 1C Shall be selected

according to provisions of 7.5.2.

8.6.3 Angle branch bended with steel pipe , considering additional thickness of processing reduction 2'C Shall be calculated according to formula (70):

)(100

32 C a

C (70)

A In the formula shall be used according to 8.5.3.

8.6.4 Consider additional thickness of minus tolerance of steel pipe thickness3

C Shall


100

3

mC (71)

3'C value can also take actual minus tolerance of steel pipe thickness.

8.6.5 Welding angle branch compressed with steel plate )5.3/( ＞w D R , Consider

additional thickness of processing reduction 2'C Take actual processing reduction

value during compressing steel plate. Consider additional thickness of reduction due

to corrosion 3'C Shall take actual minus tolerance of steel plate thickness.


For heating wall pipe of high heat flux density ( 2m/kW580 and higher), nominal

thickness4) determined according to 8.2.1 shall satisfy following conditions:

)10/(15

maxw

w

q D

D

≤ (72)

4) For internal ribbed tube and external ribbed tube, their thickness shall be measured

at root of spiral burr.

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8.8 Hydraulic test

Hydrostatic test pressure of pipe or conduit shall be taken according to relevant

boiler-making technical requirements.

8.9 stress check caused by gravity load

Subsidiary stress (axial stress, bending stress and distorting stress) of pipe wall caused

by gravity load in pipe or conduit can be checked according to formula (73):

)(4

)2(][4

2

22

ywh y

yw

w z D

D p

≤ (73)

Where:

Additional axial stress z Shall be calculated according to formula (74):

h

0001

A

F z (74)

Additional bending stress w Shall be calculated according to formula (75):

h

0001

W

M w (75)

Additional distorting stress Shall be calculated according to formula (76):

h

n500

W

M

(76)

Attenuation coefficient of ring welded seam h shall be only taken into

consideration when there is ring welded seam on checking profile, the value shall be

selected according to table 7.

z , w and in formula (73)Shall be values affect same cross sectio; if respective

maximum value of the three are not at the same cross section, then it is required to

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respectively check cross section that danger may occur.

8.10 Structural requirements

8.10.1 Angle branch roundness of heating wall pipe shall not be larger than valuesspecified in table 14

Table 14 Maximum permissible roundness of angle branch of heating wall pipe

Represent with%

Curvature radius of angle

branch's central line R ww D5.24D.1 ＜＜ R w5.2 D R≥

Roundness

100

w

wminwmax

D

D D

12 10

Note: maxw D and minw D Respectively is the maximum and minimum outside diameter of the

same cross section.

8.10.2 For non- heating conduit, when outside diameter mm76w＞ D , Angle branch

roundness shall not be larger than values specified in table 13; when outside diameter

mm76w≤ D , Angle branch roundness shall not be larger than values specified in

table 14.

8.11 Calculation for pipe bearing up external pressure

Thickness of pipe bearing up external pressure and pipe's outside

diameter mm200w≤ D , shall be calculated according to 8.2.1. Design pressure shall

take maximum external pressure, Compensation factor of elementary permissible

stress shall be 0.70 times of values listed in table 3.

8.12 Check for pipe system heat stress

Pipe system heat stress shall be checked if necessary.

9 Convex head

9.1 Signs

Signification and unit of signs used in this chapter are as follows;

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L - Theory thickness of end socket, mm;

zL - Theory thickness of end socket's straight section, mm;

min - Minimum required thickness for end socket production, mm;

s - Design calculated thickness of end socket, mm;

- Nominal thickness of end socket, mm;

0 - Theory thickness for cylinder section of hot spinning end socket with

unimpaired strength, mm;

y - Effective thickness of end socket, mm;

y' - Effective thickness for cylinder section of hot spinning end socket, mm;

- Ratio of outside diameter and inside diameter worked out according to effective

thickness of end socket;

C - Reduction due to corrosion, processing reduction and additional thickness of

minus tolerance of steel plate thickness considered during design calculation, mm;

'C - Reduction due to corrosion, processing reduction and additional thickness of

minus tolerance of steel plate thickness considered during check calculation, mm;



2C - Additional thickness of processing reduction considered during design

calculation, mm;

2C - Additional thickness of processing reduction considered during check

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60

calculation, mm;

3C - Additional thickness of reduction due to corrosion considered during design

calculation and check calculation, mm;

n D - Inside diameter of end socket, mm;

w D - Outside diameter of cylinder section of hot spinning end socket, mm;

nh - Inside height of end socket, mm;






s - Yield point or specified non-proportion elongation stress when material is at

20℃( 0.2 ), MPa;

- Attenuation coefficient of end socket;


sw - Attenuation coefficient of end socket during hydraulic test;

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61

Y - Shape factor;

d - Diameter of hole, long axis size of elliptical hole, mm.


9.2.1 Theory thickness of ellipsoidal end socket( figure 9) and spherical end socket

(figure 10) shall be calculated according to formula (77):

p

Y pD

－][2

nL

(77)

Note: Figure 9 and 10 only display some types of ellipsoidal end socket and

roundness end socket structure.

Minimum required thickness of end socket production shall be calculated according to

formula (78):

1Lmin C (78)

Design calculated thickness of end socket shall be calculated according to formula

(79):

CLs (79)

Nominal thickness of end socket shall satisfy:

s ≥

9.2.2 During check calculation, maximum permissible design pressure of end socketshall be calculated according to formula (80):

yn

y

YD

][2][

p (80)

At the same time, ][ p Shall not exceed maximum allowable pressure of end socket's

straight section determined according to formula (14).

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y Shall be calculated according to formula (81):

C y (81)

y value also can be taken by using actual minimum thickness to subtract reduction

value due to corrosion.

9.2.3 Formula (77) and (80) are effective when satisfy the following conditions:

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63

6.015.02.0nn

L

n

n ≤；≤；≥ D

d

D D

h

9.2.4 Design pressure of convex head p Shall take design pressure of conjoint body.

9.2.5 Shape factor Y Shall be calculated according to formula (82):

2

n

n

22

6

1Y

h

D (82)

9.2.6 Attenuation coefficient of end socket Shall be selected according to table 15.

Table 15 Attenuation coefficient of end socket

Structural shape of end socket

No holes, without splicing weld seam 1.00

No holes, with splicing weld seamh (refer to table 7)

With holes, without splicing weld seamn/1 Dd

With holes and splicing weld seam, Butdistance between hole center and weld edge is

larger than mm12)(0.5 d

Take less one between h and )/1( n Dd

With holes and splicing weld seam And

distance between hole center and weld edge is

less than or equal to mm12)(0.5 d

)/1( nh Dd

9.2.7 Design temperature of end socket bit shall be determined according to 5.4.

9.2.8 During design calculation, C - additional thickness of end socket can be


321 C C C C (83)

During check calculation, additional thickness of end socket C can be calculated


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321 C C C C (84)

In formula (83) and (84), 1C can be dealt with according to provisions of 6.5.2 if

consider additional thickness of reduction due to corrosion; if consider additional

thickness of processing reduction, 2C and 2C shall be determined according to

Specific processing condition of each boiler maker. In general, 2C and 2C -

reduction value of stamping technology can be selected according to table 16;

3C Shall be dealt with according to provisions of 6.5.4. If consider additional

thickness of reduction due to corrosion

Table 16 Reduction value of stamping technology

Unit is millimeter

Computing formula for reduction value

Ellipsoidal or spherical section Straight sectionStructural style

2C 2C 2C 2C

Ellipsoidal end

socket )35.0/2.0( nn ≤≤ Dh )(10.0 1L C )(09.0 3C 0 0

Deep ellipsoidal or spherical

end socket

)5.0/35.0( nn ≤≤ Dh

)(15.0 1L C )(13.0 3C 0 0

9.2.9 Besides satisfying requirements of 9.2.1, nominal thickness of end socket shall

also satisfy formula (85):

31zL C C ≥ (85)

Where, zL Shall be calculated according to formula (9) , in which min Shall take

attenuation coefficient of end socket's splicing weld h ; If there is no splicing weld.

then 00.1min , additional thickness 1C and 3C shall be respectively determined

according to 6.5.2 and 6.5.4..

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9.2.10 when n D - inside diameter of end socket is larger than 1 000 mm, nominal

thickness of end socket shall be no less than 6 mm; when n D - inside diameter of

end socket is larger than 1 000 mm, nominal thickness of end socket shall be no lessthan 4 mm.

9.2.11 Hydrostatic test pressure of end socket can be selected according to relevant

boiler-making technical requirements, but also satisfy:

][ swsw p p ≤ (86)

Maximum allowable pressure of hydrostatic test shall be calculated according to

formula (87):

s swY

p

)1()2(

)1(9.0][

33

3

sw

(87)

Where,

n y D/21 .

At the same time, hydrostatic test pressure of end socket sw p shall not exceed

maximum allowable pressure of end socket's straight section determined according to formula

(29).

9.2.12 Hot spinning convex head can be calculated according to provisions of this

chapter; But top of end socket must be excavated with processing pore after spinning

and minimum hole diameter shall no less than 80 mm; If 5.0'/ y0 ＜ for header

tank body, And rated pressure is no larger than 2.5 MPa, then it is allowed to ease

limit of n Dd / in 9.2.3 to be no larger than 0.8.

9.3 Requirements of opening pore

Opening pore in convex head shall satisfy the following conditions:

a) When there are other pores in end socket besides central pore, if pore diameter is

larger than 30 mm, then projection distance L between any two pore edges shall not

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66

be less than 3/)( 31 L L ; If pore diameter is no larger than 38 mm, Then projection

distance between any two pore edges L shall not be less than 2 L (figure 11).

b) for ellipsoidal end socket whose 35.0/ nn ≤ Dh , Projection distance from pore

edge to external wall edge of end socket shall not be less than n1.0 D (figure 11).

For deep ellipsoidal end socket and dome head whose 35.0/ nn ＞ Dh Arc length from

pore edge to connection of end socket and straight section shall be no less than

Ln D (figure 12).

c) Besides satisfying the aforesaid condition, pore locates near manhole for edge

turnup is also required to keep the distance between point of curvature of open pore

edge andPore edge turnup(or distance between welds of welding ring) no less

than (figure13).

d) Turn lateral opening shall not be excavated in welded joints.

e) When there is sealing surface kerf used for enclosing manhole as displayed in

figure 12, minimum remaining thickness of radial direction at kerf location shall not

less than min - minimum required thickness of end socket production.

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68

10 Flat-end cover and cover board

10.1 Signs


s - Design thickness of flat-end cover or cover board, mm;

1 - Nominal thickness of flat-end cover or cover board, mm;

2 - Minimum thickness at ring groove of flat-end cover, mm;

3 - Thickness of ring location at bolt fastening position of cover board or at sealing

surface, mm;

- Thickness of straight section of flat-end cover; thickness of header tank body at

location connects with flat-end cover, mm;

n D - Inside diameter of header tank body at location connects with flat-end cover,

mm;

c D - Calculation dimension of cover board, mm;

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a - Major semi-axis of elliptic cover board (nominal size), mm;

b - Minor semi-axis of elliptic cover board (nominal size), mm;

d - Open pore diameter of flat-end cover, mm;





s - Yield point or specified non-proportion elongation stress when material is at

20℃( 2.0 ), MPa;

- Compensation factor of elementary permissible stress;

K - Structural property coefficient;

i K - Height of welding angle (i=1, 2), mm;

h - Width of root faces, mm;

Y - Shape factor of cover board;

r - Semidiameter of transition circular arc of flat-end cover's reentrant angle, mm;

l - Length of flat-end cover's straight section, mm.

10.2 Flat-end cover

10.2.1 design thickness of flat-end cover shall be calculated according to formula (88)

][ns

p KD (88)

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Nominal thickness of flat-end cover shall satisfy:

s1 ≥

10.2.2 During check calculation, maximum permissible design pressure of flat-end

cover shall be calculated according to formula (89):

][][

2

n

1

KD p (89)

At the same time, ][ p Shall not exceed maximum allowable pressure of flat-end

cover's straight section determined according to formula (37).

10.2.3 Structural property coefficient K shall be selected according to table 17.

semidiameter of circular arc of flat-end cover's reentrant angle r, length pf straight

section l shall comply with requirements specified in table 17.

10.2.4 Design pressure of flat-end cover shall take design pressure of conjoint

body.

10.2.5 Design temperature of flat-end cover bit is specified in 5.4. Compensation

factor of elementary permissible stress shall be selected according to table 17.

10.2.6 Maximum allowable pressure of flat-end cover shall be calculated according to

formula (90):

s

2

n

1sw 9.0][

KD

p (90)

When determine maximum allowable pressure of hydrostatic test for flat-end cover, it

is also required to consider maximum allowable pressure of hydrostatic test for

flat-end cover's straight section (refer to 7.8).

10.2.7 Ratio of diameter of flat-end cover's center hole or long axis dimension and

inside diameter of header tank cylinder (location connects with flat-end cover) shall

be no larger than 0.8; Distance between edges of any two pore on flat-end cover shall

not less than diameter of smaller bore; Distance from pore edge to external rim of

flat-end cover shall not less than; and pore can't be excavated at circular arc section.

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10.2.8 Thickness of flat-end cover's straight section shall not be less than minimum

required thickness for production determined according to 7.2.1 when attenuation

coefficient

Table 17 Structural property coefficient of flat-end cover and compensationfactor .

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K

No. Flat-end cover type Structural requirement Without

pores

With

pores≥l

1

3

2≥r

≥l 0.40

0.45 1.0

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2

1.5≥r

12 0.8 ≥ 0.40 0.45

3 3≥r

≥l 0.40 0.45

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Table 17 (continue)

K

No. Flat-end cover type Structural requirement Without

pores

With

pores

2≥l

1

3

1≥r

And

mm5≥r

12 0.8 ≥

0.40 0.45 0.90

2 mm)5.01( ≤h 0.60 0.75 0.85

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0.60 0.75 0.85

3

≥1k

≥2k

mm)5.01( ≤h

0.40 0.40 1.05

When aIs used for hydraulic test, it is allowable to keep closed or only open a small.

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10.3 Cover board

10.3.1 Design thickness of cover board shall be calculated according to formula (91):

][

p KYDc s (91)

Nominal thickness of cover board shall satisfy:

s ≥1

10.3.2 During check calculation, maximum permissible design pressure of cover board shall be calculated according to formula (92):

][3.3][

2

1

cYD p (92)

10.3.3 Shape factor Y shall be selected according to table 18.

Table 18 Shape factor Y

b/a 1.00 0.75 0.50

Y 1.00 1.15 1.30

Note: Y value of adjacent b/a in the table can be determined with arithmetic interpolation method,

and third digit behind decimal point shall be rounded.

10.3.4 Structural property coefficient K and design dimension shall be selected

according to provisions.

a) Add stop plate between flanges (figure 14), c K D50.0 ， Take dimension of

central line on flange sealed surface.

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b) Cover board of raised-face flange type (figure15), c K D55.0 ， Take dimension

of flange bolt's central line.

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c) Cover board of plain-straight-face flange type (figure16), c K D45.0 ， Take

dimension of flange bolt's central line.

d) Cover board for internal pressure pore (figure17), 55.0 K , Round cover

board c D Shall take dimension of central line of pore ring's sealing contact surface;

elliptic cover board c D Take dimension of central line on sealing contact surface of

pore ring minor axis

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10.3.5 Design pressure of cover board p shall take design pressure of conjoint

component.

10.3.6 Design temperature of cover board bit Shall be determined according to 5.4.

10.3.7 Thickness of joint of cover board 3 shall satisfy:

13 8.0 ≥

10.3.8 Maximum allowable pressure of cover board shall be calculated according to

formula (93):

s

c

sw KYD

p

2

19.0][

(93)

When determine maximum allowable pressure of hydrostatic test for cover board, it is

required to consider maximum allowable pressure of hydrostatic test for connective

pressure parts.

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11 Reinforcement of pore

Provisions of this chapter are only applicable to radial open pore whose 8.0/ ＜n Dd ,

and mm600＜d . If pores are elliptical, these provisions are only applicable to open

pore whose ratio of long axis and minor axis is no larger than 2, and then d is

dimension of elliptical hole's long axis.

11.1 Signs


w D - Outside diameter of header tank body, mm;

n D - Inside diameter of boiler barrel body or header tank body, mm;

wd - Outside diameter of welded pipe's joint or pipe, mm;

nd - Inside diameter of welded pipe's joint or pipe, mm;

d - Diameter of pore in boiler barrel body or header tank body, Inside diameter of

push-in type integral welding pipe head, push-in type double fillet weld pipe head (or

pore ring), dimension of elliptical hole on longitudinal section of barrel body, mm;

][d - Maximum permissible diameter of non reinforced pore, mm;

d

d ][ - Maximum permissible equivalent diameter during pore-bridge computation of

reinforcement, mm;

0 - Theory thickness of boiler barrel body or header tank body with unimpaired

strength, mm;

y - Effective thickness of boiler barrel body or header tank body, mm;

- Nominal thickness of boiler barrel body or header tank body, mm;

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10 - Theory thickness of reinforcing pipe head, mm;

y1 - Effective thickness of reinforcing pipe head, mm;

1 - Nominal thickness of reinforcing pipe head, " pipe head thickness" for short,

mm;

2 - Thickness of reinforcing pad plate, mm;

- Effective thickness of reinforcing pipe head, mm:

1 - Dimension of reinforcing pipe head protending out internal wall of boiler barrel

body and header tank body, mm;

b - Effective reinforcing width of boiler barrel body or header tank body, mm;

- Design pressure, MPa;

][ - Permissible thickness of boiler barrel body or header tank body, MPa;

c 1][ - Permissible stress of pipe head, MPa;

2][ - Permissible stress of backing board, MPa;

w - Before reinforcing, longitudinal, double transverse or oblique equivalent

attenuation coefficient of reinforced pore bridge, which is calculated according to pore

diameter;


s - Pitch between two adjacent holes in longitudinal (axial) direction, mm;

s - Pitch between two adjacent holes in transverse direction mm;

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s - Pitch between two adjacent holes along oblique direction, mm;

A - Area reinforcement required on longitudinal section, 2mm ;

1 A - Weld area that has reinforcing action in longitudinal section 2mm ;

2 A - Pipe head area that has reinforcing action in longitudinal section 2mm ;

3 A - Backing board area that has reinforcing action in longitudinal section, 2mm ;

4

A - Area of boiler barrel body or header tank body that has reinforcing action in

longitudinal section, 2mm ;

e - Height of weld leg of welding pipe head in longitudinal section, mm;

K - Reduction coefficient for oblique pore bridge;

k - —Coefficient.

11.2 Non reinforced pore and its maximum permissible diameter

11.2.1 Expanded joint pore, screw hole and other non- welded pores are all

non-reinforced opening; If welding type of connection between pipe head and boiler

barrel body or header tank body don't comply with reinforcement structural shape

specified in 11.3, or can't satisfy requirements of 11.4.4 although complying with 11.3,

pores under such condition will be considered as non reinforced pore.

11.2.2 for push-in type integral welding pipe head, push-in type double fillet weld

pipe head (or pore ring), when1

][ - permissible stress of pipe head (or hole circle)

material is less than ][ - permissible stress of barrel body material, d in

computation of reinforcement in this chapter shall take sum of inside diameter of pipe

head (or hole circle) and ])/[]([-[12 11 .

11.2.3 For non reinforced pore on boiler barrel body or header tank body, its

maximum permissible diameter shall not exceed value ][d determined according to

figure 18 and figure 19.

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83

for boiler barrel body, y in figure shall be calculated according to (13), Coefficient

k shall be calculated according to formula (94):

y

n

p pDk

)][2( (94)

For header tank body, figure n D shall be calculated r wn D D 2 , y shall be

calculated according to formula (36):, system k can be calculated according to

formula (95):

y

yw

p

D pk

)][2(

)2(

(95)

When 23

n mm10130＞ y D , select through the formula 23

n mm10130 y D ; once

it is found that mm200][ ＞d , take mm200][ d .

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Figure 18 Maximum Permissible Diameter of Non-reinforced Pore

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Figure 19 Maximum Permissible Diameter of Non-reinforced Pore

11.3 Reinforcement of pore

Structural shapes displayed in figure 20 shall be treated as reinforcement structure,

among which, a), b) and c) Structural shape are only applicable to boiler whose rated

pressure is no larger than 2.5 MPa. At the same time, structural shape a) is only

applicable to non- heating boiler barrel body and its computation method of

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reinforcement shall be treated as d) type integral welded construction.

11.4 Reinforcement calculation of pore

11.4.1 Reinforcement is required to conduct according to 11.4.2~11.4.4 for

single-hole whose open-pore diameter is larger than maximum permissible diameter

of non reinforced pore as determined according to 11.2.3, or for two adjacent pores

whose open-pore diameter is larger than maximum permissible diameter of non

reinforced pore as determined according to 11.2.3 and pitch is no less than value

determined according to formula (18).

11.4.2 When coefficient of boiler barrel body or header tank body 40.0＞k , It is

required to use reinforcement structure specified in 11.3 if open-pore diameter of boiler barrel body or header tank body exceeds maximum permissible diameter of non

reinforced pore determined according to 11.2.3. When coefficient 40.0k , there is no

need to conduct reinforcement.

11.4.3 Effective range of open pore reinforcement is displayed in range of ABCD in

figure of table 19.

Effective reinforcement height shall be selected according to following provisions:

When 19.0/1 ≤nd , take the minimum value of 15.2 h and 5.2h ;

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When 19.0/1 ＞nd , take 11)( nd h ;

Width of effective reinforcement shall take: nd b 2 ;

If pore is elliptical,, then nd Is dimension on longitudinal section.

11.4.4 Open pore reinforcement shall satisfy following conditions:

A A A A A 4321 (96)

And 2/3 area of reinforcement required shall dispersed over at a range of 1/4 porediameter beside pore.

When use reinforcement structure listed in table 19, calculation method for each area

in formula (96) are as showed in table. 100 、 in table shall be calculated according

to the following formula:

For boiler barrel body:

p

pDn

][20

(97)

For header tank body:

p

D p yw

][2

)2(0

(98)

For pipe head:

p

d p yw

1

1

01][2

)2(

(99)

For elliptical hole, wd Refers to long axis dimension.

y shall be calculated according to formula (36), y1 shall be calculated according

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to formula (56).

When permissible stress of reinforcing component steel products is larger than that of

reinforced component steel products, calculation shall be conduct according to

permissible stress of reinforced component steel products.

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Table 19 Reinforcement area of pore and calculation

type b) and c) in figure20 d) and e) in figure20 f) and g

Reinforcement

scope

A

01

1][

][12

ynd 0

11

][

][12

ynd

0 nd

1 A 22e )(2 22 ee 或 2

e

2 A

][

][]2)(2[ 1

11101

y y hh

][

][]2)(2[ 1

11101

y y hh (2 1 yh

3 A

][

][)2(0.8 2

12

nd b

0 0

4 A

)(][

][12- 0

11

y ynd )(

][

][12- 0

11

y ynd

( ynd

Note: for structural shapes f) and g) in figure20, when open-pore diameter d is different from nd - inside diameter of pipe he

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11.5 Computation of reinforcement for pore-bridge

Calculation of this this section is applicable to pore bridge that pitch of two adjacent

pores is less than value determined with formula (18); and diameter of these two poresare less than maximum permissible diameter of non reinforced pore determined

according to 11.2.3.

11.5.1 For pore bridge that pitch of two adjacent pores is less than value determined

according to formula (18), If diameter of one of the two pores is larger than maximum

permissible diameter of non reinforced pore determined according to 11.2.3,

Reinforcement shall be conducted according to 11.4.2 to 11.4.4 under the condition of

satisfying requirements of a) and b) in 11.5.2. If s - pitch of two pores is less than sum

of their diameters, width of effective reinforcement in 11.4.3 shall

take 11)(2 d d sb ， Is diameter of small pore. After reinforcement, this pore shall be

treated as imperforate in this pore bridge. if diameter of the two pores is larger than

maximum permissible diameter of non reinforced pore determined in 11.2.3, it is

required to deal with the situation according to relevant regulations of chapter 13.

11.5.2 When longitudinal, transverse or oblique pore bridge on boiler barrel body or

header tank body are reinforced with pipe so as to improve attenuation coefficient of

pore bridge, following requirements shall be satisfied firstly:

a) adopt welding structures showed in d), e), f), g) of figure20

b) Permissible minimum attenuation coefficient shall comply with formula(100):

w3

4][ ＜ (100)

11.5.3 When conduct computation of reinforcement for longitudinal, transverse or

oblique pore bridge on boiler barrel body or header tank body, maximum permissible

equivalent diameter d][d shall be calculated according to the following formula:

For longitudinal pore bridge:

sd ])[1(][ d (101)

For transverse pore bridge:

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'2

][1][ d sd

(102)

For oblique pore bridge:

s K

d

][1][ d

(103)

Permissible minimum attenuation coefficient ][ can be calculated according to

formula (12) or (35), Reduction coefficient for oblique pore bridge K shall be

calculated according to formula (22).

11.5.4 Pipe head used for reinforcing pore bridge (figure21) shall satisfy the following

conditions:

a) For pore bridge whose adjacent pipe head are same in structure and size:

yd

0

21 ][

d

A A A ≥ (104)

Where, 1 A A、 and 2 A shall be calculated according to formula in table 19.

b) For pore bridge whose adjacent pipe head are different in structure and size:

yd

0

2121 ][2

d

A A A A A A ≥ (105)

Where, 21 A A A 、、 and 21 A A、 A 、 shall be respectively calculated according to

formulae which used to calculate 21 A A A 、、 in table 19.

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11.6 Check calculation for weld strength

It is allowable to conduct recomputation for fillet weld strength of reinforcing

component, boiler barrel body or header tank body. weld calculated height of

reinforcing component shall take height of weld leg.

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12 Odd components

12.1 Signs


L - Calculated welding trifurcated connector, main pipe of hammering trifurcated

connector, transition zone and equal-diameter Y-tube, mm;

1L - Theory thickness of welding trifurcated connector and hammering trifurcated

connector branch pipe, mm;

min - Minimum required thickness for production of calculated welding trifurcated

connector, main pipe of hammering trifurcated connector, transition zone and

equal-diameter Y-tube; , mm;

1min - Minimum required thickness for production of welding trifurcated connector

and branch pipe of hammering trifurcated connector, mm;

b - Minimum required thickness for production of branch pipe of hot-extrusion

trifurcated connector, mm;

c - Minimum required thickness for production of top of main pipe's cylinder part

of hot extrusion straight type trifurcated connector, or that of top of main pipe's

cylinder part before narrowing-mouth of drum type trifurcated connector, mm;

r

- Minimum required thickness for production of bottom of main pipe's cylinder

part of hot extrusion straight type trifurcated connector, mm;

r1 - Minimum required thickness for production of bottom of main pipe's cylinder

part behind narrowing-mouth of hot aftertrusion drum type trifurcated connector, mm;

r2 - Minimum required thickness for production of top of main pipe's cylinder part

before narrowing-mouth of hot extrusion drum type trifurcated connector, mm;

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t - Minimum required thickness for production of bottom of main pipe's cylinder

part before narrowing-mouth of hot extrusion drum type trifurcated connector, mm;

s - Design calculated thickness of main pipe of welding trifurcated connector, mm;

1s - Design calculated thickness of branch pipe of welding trifurcated connector,

mm;

- Nominal thickness of main pipe of welding trifurcated connector, mm;

l

- Nominal thickness of branch pipe of welding trifurcated connector, mm;

y - Effective thickness of calculated welding trifurcated connector, main pipe of

hammering trifurcated connector, transition zone of hot extrusion trifurcated

connector and equal-diameter Y-tube; , mm;

1y - Effective thickness of welding trifurcated connector and branch pipe of

hammering trifurcated connector, mm;


minus tolerance of steel pipe thickness considered during design calculation. mm;


minus tolerance of steel pipe thickness considered during check calculation, mm;


w D - Outside diameter of trifurcated connector main pipe and equal-diameter Y-tube,

mm;

n D - Inside diameter of trifurcated connector main pipe and equal-diameter Y-tube,

mm;

p D - Mean diameter of trifurcated connector main pipe, mm;

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wd - Outside diameter of trifurcated connector branch pipe, mm;

nd - Inside diameter of trifurcated connector branch pipe, mm;

maxnd - Maximum inside diameter of branch pipe under the condition of hot extrusion

trifurcated connector can satisfy strength requirement of transition zone, mm;

pd - Mean diameter of welding trifurcated connector and hammering trifurcated

connector branch pipe, mm;

h - Minimum altitude of hot extrusion trifurcated connector branch pipe(Refer tofigure. 25, 26), mm;

R - Maximum knuckle radius of hot extrusion trifurcated connector shoulder(Refer to

figure. 27, 28), mm;

L - Minimum length of open pore limited by hot extrusion trifurcated connector main

pipe(Refer to figure 29, 30), mm;

1 L - minimum half length of open pore limited by hot extrusion trifurcated connector

main pipe (Refer to figure. 25, 26), mm;

2 L - Distance from external rim of connector's welded seam to external rim of

welding trifurcated connector's welded seam(Or to truncation intersection of

hammering trifurcated connector's internal wall), mm;

- Ratio of outside diameter and inside diameter calculated according to effective

thickness of trifurcated connector main pipe and equal-diameter Y-tube. ;

L - Ratio of outside diameter and inside diameter calculated according to theory

thickness of trifurcated connector main pipe and equal-diameter Y-tube. ;



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r - Attenuation coefficient;

- Central angle of open pore limited by hot extrusion trifurcated connector branch

pipe(Refer to figure31), (°);

X , Y - Coefficient;

Bd - Diameter of reinforcement rib, mm;

B - Thickness of reinforcement plate, mm;

Bh - Height of reinforcement plate, mm.

12.2 Seamless steel tube welding trifurcated connector

12.2.1 Theory thickness of welding trifurcated connector can be calculated according

to the following formula:

For main pipe:

p

D p

y

w L

][2

(106)

For branch pipe:

w

w L L

D

d 1 (107)

Minimum required thickness for production of welding trifurcated connector can be

calculated according to the following formula

For main pipe:

1min C L (108)

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For branch pipe:

11min1 C L (109)

Design calculated thickness of welding trifurcated connector can be calculated

according to the following formula:

For main pipe:

C L s (110)

For branch pipe:

C L s 11 (111)

Nominal thickness of welding trifurcated connector shall satisfy:

For main pipe:

s ≥

For branch pipe:

s11 ≥

12.2.2 During check calculation, maximum permissible design pressure of welding

trifurcated connector shall be calculated according to formula (112):

yw

y y

D p

][2][ (112)

Effective thickness y shall be calculated according to formulae (113):

C y (113)

y value also can be taken by using actual minimum thickness to subtract reduction

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value due to corrosion.

12.2.3 Formula (106), (107) and (112) are applicable to the scope of

0.8/mm813 nnw ≥、≤ Dd D

12.2.4 Take design pressure of conjoint component as design pressure of welding

trifurcated connector ( ).

12.2.5 Design wall temperature bit of welding trifurcated connector shall be

determined according to 5.4.

12.2.6 figure 22 are structural shape of single reinforcement, butterfly reinforcingwelding trifurcated connector. If welding trifurcated connector of thickness

reinforcement is used, it is required to use connector of e), f) and g) type in figure20.

attenuation coefficient y shall be determined according to table 20, value in

table shall be calculated according to formula (46), value L shall be calculated

according to formula (38).

Figure 22 Single Reinforcement and Butterfly Reinforcement Type of Welding Trifurcated

Connector

Table 20 Attenuation coefficient y of welding trifurcated connector

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bit w D、、 L Reinforcement

typey

a10.105.1 ＜≤ butterfly 0.90

butterfly 0.90Single

reinforcement0.90

Temperature that is less than long-time

strength of steel products but may have

controlling influence to elementary

permissible stress

≤10.1 and

50.1≤ L Thickness

calculate according to

formula (114)

10.105.1 ＜≤ butterflycalculate according to

formula (114)

25.110.1 ＜≤ and

mm813mm273 ≤＜ w D

Butterfly or

single

reinforcement

calculate according to

formula (114)

25.110.1 ＜≤ and

mm273≤w D

Butterfly or

single

reinforcement

0.70

＜25.1 and 00.2≤ L Thicknesscalculate according to

formula (114)

Temperature that is no less than long-time

strength of steel products but may have

controlling influence to elementary

permissible stress

＜25.1 and 05.1≤ L

Butterfly or

single

reinforcement

0.70

a For welding trifurcated connector of boiler seamless steel tube whose rated pressure is no larger than 2.5 MPa, When

outside diameter of main pipe, it is allowed to adopt thickness reinforcement type; and the attenuation coefficient shall

take 2/3 of calculated value of calculation (114).

12.2.7 Attenuation coefficient of trifurcated connector can be calculated according to

formula (114):

)]2/(11[20.1

1

2y

Y Y X

(114)

Where:

)/( p p

2

n d Dd X ;

)/()(05.4 y p

2

y

3

1

3

y D yY .

12.2.8 Additional thickness of welding trifurcated connector C C 、 can be calculated

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100

according to those specified in 7.5 and 7.6.

12.2.9 Material of reinforcement component of welding trifurcated connector shall be

same as that of main pipe and its dimension shall satisfy values required in table 21.

12.2.10 For non-heat-insulated welding trifurcated connector, its maximum

permissible thickness shall comply with those specified in 7.7.

12.2.11 As displayed in figure 23, pore shall be avoided in area of ABCD trifurcated

connector. Pores must be distributed in range of arc length l if it is necessary to open

pore, and their diameter shall not be larger than 1/4 of w D and also in the limit of 60

mm. At the same time, 2 L - distance from external rim of connector's welded seam

to external rim of welding trifurcated connector's welded seam shall be no less than20 mm. For pore bridge, when determine theory thickness and maximum permissible

design pressure of trifurcated connector with formula (106) and (112), y shall use

y got according to 12.2.6 and take minimum value of min - Minimum pore bridge

attenuation coefficient got by referring to those specified in 6.4.

12.2.12 Hydrostatic test pressure of welding trifurcated connector shall be taken

according to relevant boiler-making technical requirements but shall not exceed value


Table 21 Dimension requirement of reinforcement component

Unit is millimeter

Size of reinforcement componentReinforcement type

20≤ 20＞

Butterfly

6B

B

h

120B

B

h

Single reinforcement 5.1B d

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12.3 Hammering trifurcated connector

12.3.1 computing formulae for minimum required thickness for production of

hammering trifurcated connection, maximum permissible design pressure and ,

L , Design pressure, design temperature, maximum permissible thickness of

non-heat-insulated hammering trifurcated connector and hydrostatic test pressure shall

be dealt with according to provisions about welding trifurcated connector.

12.3.2 Hammering trifurcated connector shall adopt thickness reinforcement and its

attenuation coefficient y shall be calculated according to formula (114).

12.3.3 When design temperature bit is less than temperature at which long-time

strength of steel products may have controlling influence to elementary permissible

stress, these aforesaid provisions of hammering trifurcated connector are applicable to

the condition that ≤10.1 and 50.1L≤ ; when design temperature bit is less

than temperature at which long-time strength of steel products may have controlling

influence to elementary permissible stress, they are applicable to the condition that

＜52.1 and 00.2L≤ .

12.3.4 Structural requirements of hammering trifurcated connector are showed in

figure 24 and radius of rounded angle in the figure can take smaller one of the

following values:

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a) 10 mm;

b) 1/4 of thickness of thicker part at turning.

12.3.5 Hammering trifurcated connector showed in figure 24 shall avoid open pore,Pores must be distributed in range of arc length l if it is necessary to open pore, and

their diameter shall not be larger than 1/4 of wD , And in the limit of 60 mm, 2L -

distance from external rim of connector's weld to internal wall truncation intersection

of trifurcated connector shall be no less than 20 mm. For pore bridge, it is required to

deal with according to 12.2.11.

12.4 Hot extrusion trifurcated connector

This strength calculation method for hot extrusion trifurcated connector is onlyapplicable to straight type trifurcated connector and drum type trifurcated connector

that made from seamless steel tube through hot extrusion molding with sets of moulds.

Straight type trifurcated connector refers to trifurcated connector whose diameter of

branch pipe is no larger than diameter of main pipe; and mainstream passage of

trifurcated connector shows in straight lines as showed in figure 25.

Drum type trifurcated connector refers to trifurcated connector whose diameter of

branch pipe is larger than diameter of main pipe; and it is got through necking down

of equal-diameter straight type trifurcated connector; the section necking down shall

transit smoothly; mainstream passage of trifurcated connector shows in drum shape as

showed in figure 26.

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12.4.1 Minimum required thickness for production of cylinder at pipe end of main

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pipe and branch pipe of hot extrusion trifurcated connector shall be calculated

according to formula (33).

12.4.2 p - design pressure of hot extrusion trifurcated connector shall take design

pressure of conjoint component, design temperature bit shall be determined

according to 5.4.

12.4.3 Thickness calculation for transition zone of hot extrusion trifurcated connector

(refer to area ABCD in figure 27, 28).

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a) Trifurcated connector that mm660w ≤ D , theory thickness shall be calculated


2][9.1

3.1 w

p

pD L

(115)

Minimum required thickness for production shall be calculated according to formula

(116):

1min C L (116)

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b) For trifurcated connector mm660w＞ D , Theory thickness can be calculated


10][2

3.1 w

p

pD L

(117)

Minimum required thickness for production shall be calculated according to formula

(118):

1min C L (118)

12.4.4 During check calculation, maximum permissible design pressure of hotextrusion trifurcated connector shall be calculated according to the following formula:

a) for trifurcated connector that mm660w ≤ D :

)2(1.3

)2]([9.1[][

yw

y

D p (119)

b) for trifurcated connector that mm660w＞ D :

)10(1.3

)10]([2][

yw

y

D (120)

y value shall be taken by subtracting reduction value due to corrosion from actual

minimum thickness in transition zone.

At the same time, maximum permissible design pressure of hot extrusion trifurcated

connector worked out with formula (119) or (120) shall not exceed that of cylinder

section of main pipe and branch pipe calculated according to formula (37).

12.4.5 Determination for other size of straight type trifurcated connector

r shall take 1L8.0 C And larger value of thickness calculated according to

formula (33);

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c shall take larger value of r and min ;

b shall take )( maxnw d d And larger value of thickness calculated according to

formula (33);

nmaxd shall be calculated according to formula (121) or (122);

Refer to table 22 for provisions about 1 L L Rh 、、、 of straight type trifurcated

connector.

12.4.6 Determination for other size of drum type trifurcated connector:

t shall take 1L8.0 C And larger value of thickness calculated according to

formula (33);

c shall take larger value of r and min ;

r1 shall be calculated according to formula (33), when twr1w 5.00.5 d D ＞ ,

r1 shall be increased so as to Prevent that available metal being cut;

r2 shall be calculated according to formula (33), when

cw2r w 5.00.5 d D ＞ , it is required to increase r2 , so as to prevent that available

metal being cut;

Calculation method for bnmax 、d is same to that of straight type trifurcated

connector; refer to table 23 for 1 L L Rh 、、、 of drum type trifurcated connector.

12.4.7 maxnd - maximum inside diameter of branch pipe under the condition of hot

extrusion trifurcated connector whose mm660w ≤ D can satisfy strength

requirement of transition zone(refer to figure 27) shall be calculated according to

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formula (121):

22

minwnmax )(22 R R Rd d (121)

12.4.8 maxnd - maximum inside diameter of branch pipe under the condition of hot

extrusion trifurcated connector whose mm660w＞ D can satisfy strength

requirement of transition zone (refer to figure 28) shall be calculated according to

formula (122):

minwnmax 2 d d (122)

12.4.9 For drum type trifurcated connector, w D in 12.4.3, 12.4.4, 12.4.7 and 12.4.8,

Shall take outside diameter before trifurcated connector necking down, namely

outside diameter of branch pipe of drum type trifurcated connector wd .

12.4.10 Additional thickness of reduction due to corrosion - 1C shall be determined

according to provisions of 7.5.2. in order to guarantee minimum required thickness of

hot extrusion trifurcated connector required in 12.4.3, 12.4.5 and 12.4.6, thickness of

seamless steel tube before extrusion must be determined according to material and

technology condition

Table 22 specified value for 1,,, L L Rh straight type trifurcated connector

Unit is millimeter

Nominal size of

trifurcated

connector

h R 1 L L

254×254×203

273×273×219203 46 381

254×254×254

273×273×273216 51 381

305×305×203 229 51 432

305×305×254 241 62 432

305×305×305

324×324×273324×324×324

254 61 432

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356×356×254 257 61 457

356×356×305 270 72 457

356×356×324

356×356×356279 67 457

406×406×305 295 67 457406×406×356 305 71 483

406×406×406 305 76 483

457×457×356 330 71 546

457×457×406 330 75 546

457×457×457 343 86 546

508×508×457 368 84 597

509×508×508 381 95 597

559×559×508 406 92 660

559×559×559 419 105 660

610×610×559 432 102 718

610×610×610 457 114 718

660×660×660 495 124 762

711×711×711 520 133 762

762×762×762 559 143 832

813×813×813 597 152 876

864×864×864 635 162 933

914×914×914 673 171 965

Table 23 specified value of 1 L L Rh 、、、 of drum type trifurcated connector

Unit is millimeter

Nominal size of

trifurcated

connector

h R L 1 L

203×203×254 216 51 330 381

254×254×305

273×273×324254 61 330 432

254×254×356 279 67 413 457

305×305×356324×324×356

279 67 305 457

305×305×406 305 76 362 483

325×325×377

324×324×406

356×356×406

305 76 362 483

356×356×457 343 86 462 540

356×356×508 381 95 529 597

356×356×559 419 105 716 743

356×356×610 457 114 716 743

406×406×457 343 86 360 540

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406×406×508 381 95 451 597

406×406×559 419 105 652 679

406×406×610 457 114 652 718

457×457×508 381 95 406 597

457×457×559 419 105 581 660457×457×610

450×450×635457 114 581 718

508×508×559 419 105 502 660

508×508×610 457 114 502 718

508×508×660 495 124 591 762

508×508×711 521 133 591 762

559×559×610 457 114 461 762

559×559×660 495 124 591 762

559×559×711 521 133 591 762

610×610×660 495 124 505 762

610×610×711 521 133 505 762

660×660×711 521 133 402 762

12.4.11 For non-heat-insulated hot extrusion trifurcated connector, its maximum

permissible thickness shall comply with those specified in 7.7.

12.4.12 Open pore limit of hot extrusion trifurcated connector

Straight type trifurcated connector and drum type trifurcated connector arerespectively divided into several areas as showed in figure 29 and figure 30. As

showed in figure 31, central angle which corresponding to width of B, F, E area

are related to outside diameter of trifurcated connector's branch pipe; refer to table 24

for relation between outside diameter of branch pipe and angle . height of area E Is

arc length distance in range of 20° above horizontal center line and 10° below

horizontal center line.

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Table 24 relation between outside diameter of branch pipe and angle

Outside diameter

of branch

pipe/mm

outside

diameter

of branch

pipe/mm

203, 219 27° 508 40°

254, 273 32° 559 39°

305, 324 36° 610 38°356, 377 41° 660, 711 37°

406 43° 762, 813 36°

457 41° 864, 914 35°

Adopt this method, area A accepts open pore for straight type trifurcated connector;

Open pore is permissible for drum type trifurcated connector and exit trifurcated

connector; Entrance trifurcated connector only can be open at location where inside

diameter is constant. Area C and E shall not open pore. Area B and F are inadvisable

to open pore, Under avoidless condition, it is allowable to open pores along axial

direction of branch pipe at area F of every kind of trifurcated connector and area B of

entrance trifurcated connector. It is forbidden to open pore at entrance trifurcated

connector and area D of radiation reheater's export trifurcated connector; it is allowed

to open pore at other trifurcated connector. Refer to 6.4 to calculate attenuation

coefficient of open pore.

open-pore diameter of trifurcated connector area shall not be larger than 1/4 of w D ,

And in the limit of 60 mm

12.4.13 Hydrostatic test pressure of hot extrusion trifurcated connector shall be taken

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according to relevant boiler-making technical requirements but shall not exceed value


12.5 Equal-diameter Y-tube

12.5.1 Calculation method of this section is only applicable to equal-diameter Y-tube

that 00.205.1mm，108 Lw ≤≤≤ D .

12.5.2 Minimum required thickness for production, maximum permissible design

pressure, design pressure, design temperature, additional thickness and hydrostatic

test pressure of equal-diameter Y-tube (figure 32) shall be dealt with as those specified

for welding trifurcated connector.

12.5.3 Equal-diameter Y-tube can be bended, hammered and casted with steel pipe or

formed with steel plate through pressure welding. Attenuation coefficient y Can be

taken and used according to following provisions:

When design temperature bit Is less than temperature at which long-time strength of

steel products may have controlling influence to elementary permissible stress:

0.70y ;

When design temperature bit Is not less than temperature at which long-time strength

of steel products may have controlling influence to elementary permissible stress:

0.60y .

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13 Proof method for determining maximum permissible design pressure of

component

13.1 Signs


][ p - Maximum permissible design pressure at working temperature, MPa;

ysi p - Proof pressure at test temperature (i=1, 2, 3, 4), MPa;

ysmin

p - Minimum proof pressure at test temperature, MPa;

ss p - At test temperature, pressure when weakest positions reach yield, MPa;

bs p - Bursting pressure at test temperature, MPa;


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J][ - Elementary permissible stress at working temperature, MPa;

JS][ - Elementary permissible stress at test temperature, MPa;

b - Tensile strength when material is at 20℃, MPa;

sLs - Actual yield point or specified non-proportion elongation stress when test

component material is at test temperature( 2.0 ), MPa;

1b - Actual tensile strength when test component material is 20℃, MPa;

dmax - Maximum equivalent stress in region of high stress, MPa;

dmax - Maximum equivalent stress in region of low stress, MPa;

pdmax - Maximum value of equivalent stress of inside and outside wall mean

stress in high stress region, MPa;

pdmax - Maximum value of equivalent stress of inside and outside wall mean

stress in low stress region MPa;

p R - Mean radius of curvature at discontinuous location of shell of revolution,

mm;

pp R - Mean value of mean radius of curvature between two adjacent high stress

regions on shell of revolution, mm;

min - Minimum thickness of discontinuous section, mm;

pmin - Mean value of minimum thickness of two adjacent high stress regions,

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mm;

- Strain capacity, %;


- Relative error of strain measurement;

f - Quality coefficient of casting;

ys - Thickness of most weak position of component for proof test, mm;

yz - Actual thickness of applied component relevant to test component at

location of ys , mm.

13.2 General requirements

13.2.1 this chapter provides proof test and finite element calculation methods which

are used to determine component's maximum permissible design pressure, these

methods include: stress proof method, yield proof method, blasting proof method and

stress analysis proof method.

13.2.2 methods offered in this chapter are applicable to pressure parts that can't be

calculated according to provisions of antecedent chapters in this standard.

12.2.3 boiler components that adopt methods offered in this chapter to determine

maximum permissible design pressure shall use materials that comply with relevant

regulations in chapter 5. At the same time, there shall be adequate rounded angle at all

turns of component. radius of rounded angle shall be no less than smaller value of the

following values:

a) 10 mm;

b) 1/4 of thickness of thicker part at connection part of rounded angles.

13.3 Stress proof method

This method shall be conducted according to the following provisions (equivalent

stress shall be calculated according to theory of maximum shear stress strength):

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A) It is required to stick strain gauge inside and outside wall of component at points

which corresponding to locations where high stress may appear, and strain gauge also

shall be stuck properly at corresponding points of other locations.

B) boost and reduce pressure according to certain pressure grading; record pressurevalue of each grade and strain value of relevant measuring point. Test maximum

pressure shall take the situation as final that both inside and outside wall have no yield.

Boost and reduce pressure for several times until reproducibility of measured data is

approved.

C) according to stress value acquired through proof test and its distribution, stressed

zone can be divided into primary stress, secondary stress and one local membrane

stress according to following provisions:

1) primary stress-stress of test component in area without influence of structure'sdiscontinuity

2) local membrane stress - When equivalent stress value of mean stress on inside and

outside wall of component is no less than range of ][1.1 . size at meridian direction

of shell of revolution shall be no larger than min p R , And edge spacing between two

such region shall be no less than min p pp R , Then such stress belongs to once local

membrane stress

3) Secondary stress - local bending stress, which is aroused at neighboring areas of

discontinuous location of test components, in order to satisfy deformation

compatibility condition

For convenience, area with primary stress is named as low stress area; area with once

local membrane stress or secondary stress is named as high stress region.

d) Work out p max pd relation straight line of extremal vertex of equivalent stress of

inside and outside wall mean stress in low stress region, Work out pressure ys1 p

correspond to on such line ][ (figure 33).

e) Work out pmaxd relation straight line of extremal vertex of equivalent stress in

low stress region, Work out pressure 2ys p that corresponds to ][5.1 (figure 34).

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f) Work out pmax pd relation straight line about extremal vertex of equivalent

stress of inside and outside wall mean stress in high stress region Work out pressure

ys3 p that correspond to ][5.1 (figure 35).

g) Work out pmaxd relation straight line of extremal vertex of equivalent stress in

high stress region, Work out pressure ys4 p that corresponds to ][3 (figure 36).

Figure 33 pmaxd straight line of extremal vertex of equivalent stress of inside

and outside wall mean stress in low stress region

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Figure 34 pmaxd straight line of extremal vertex of equivalent stress in low stress

region

Figure 35 pmaxd straight line of extremal vertex of equivalent stress of inside

and outside wall mean stress in high stress region

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Figure 36 pmaxd straight line of extremal vertex of equivalent stress in high

stress region

h) take minimum value among 4ysys32ysys1 、 p p p p 、、 to be ysmin p .

i) Estimate relative error of strain measurement. If relative error is Δ, Then maximum

permissible design pressure of component shall be determined according to formula

(123):

1][

minys p p (123)

Maximum permissible design pressure [ p] determined according to formula

(123)Shall be revised according to practical situation by considering temperature and

thickness difference when it is used for untried components of same type.

13.4 Yield proof method

This method is only applicable to component whose working temperature is less than

temperature at which long-time strength of such steel products may have controlling

influence to elementary permissible stress; in addition, component material shall

satisfy the following conditions:

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Component for yield proof shall be without strain-hardening and internal stress before

test, And also without hydraulic test, otherwise, it is required to conduct proof test

after stress-relief heat treatment for component.

Maximum permissible design pressure of component shall be determined according to

formula (124):

s s

p p

1

hJss ][0.75][

(124)

Where, J][ Shall take elementary permissible stress of component material at

working temperature.

For component whose inside and outside wall can be checked regularly after being

put into operation, maximum permissible design pressure can be increased to 1.25[ p]

if necessary.

When maximum permissible design pressure determined according to formula (124)

is used for untried components of same type, it is required to revise according to

practical situation by considering thickness difference.

Yield pressure of component ss p Can be determined with strain measurement method:

Stick strain gauge at outside wall of location where high stress may appear and boost pressure slowly, Record pressure value of each grade and strain value of each relevant

measuring point; work out p curve about extremal vertex of strain value; take

pressure whose relevant residual strain is 0.2% as (figure 37).

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13.5 Blasting proof method

Specimens for this method shall be no less than three and take minimum value of test.

Maximum permissible design pressure of component shall be determined according to

formula (125)

f p

p h

b1Jsys

bJyz bs

][4

][][

(125)

For cast steel component, f shall take 0.7; All other components take 0.1 f .

13.6 Stress analysis proof method

13.6.1 Responsibilities of design unit are as follows:

A) design unit shall affirm veracity and integrality of conditions for analyses and

design.

b) Design unit shall be responsible for veracity and integrality of conditions for design

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document.

C) design document shall include report for stress analysis, design sketch and

simplified illustration of calculation.

d) General plan of components used to analyses design technique shall be marked

with approval mark of design unit using this standard.

13.6.2 Stress analysis calculation shall comply with the following provisions:

a) Procedure of adopted finite element computational analysis shall be equipped with

integrated program description documents, user guidance and standard model tests.

Results of calculation shall be compared with available analytic solution, numerical

solution or experimental result so as to prove reliability of calculation procedure. It

also allowed using international structural analysis calculation procedure.

B) stress shall be calculated according to virtual linear elasticity or elastic theory;

equivalent stress shall be tidied according to maximum shearing stress theory.

c) Method for stress classification and determining maximum permissible design

pressure can be used according to provisions of 13.3.

Appendix A

(Normative appendix)

Calculation for boiler barrel's low cycle fatigue life

A.1 General provisions

A.1.1 Scope of application

This method is applicable to calculation for low cycle fatigue life of boiler barrel that

designed according to this standard, made according to relevant regulations and

certificated through inspection.

A.1.2 Structural requirement

A.1.2.1 for boiler barrel using this method to calculate low cycle fatigue life, at its

open pore locations that need fatigue examination, joint type between connector and

boiler barrel body is integral welding construction as showed in figure A.1. Figure A.1

e) is molding structure of elliptic flued opening, whose ratio of long and minor

semi-axis of inner projection is 2∶

1.

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A.1.2.2 If it is necessary to conduct fatigue check for other locations of boiler barrel,

it is suggested to calculate referring to A.4 and A4.5 of this method after analysis

stress under cycle working condition with other efficient ways.

A.1.3 Determination condition for fatigue calculation

A.1.3.1 calculation for low cycle fatigue life of boiler barrel must be conducted for

peak-regulation load unit.

A.1.3.1 there is no need to calculate low cycle fatigue life of boiler barrel for units

only bearing base load.

A.1.3.3 for unit that start and stop frequently and also with larger parameter

undulation, calculation for low cycle fatigue life can be avoided if cumulative damage(due to cyclic variation of working condition such as start-up - boiler shutdown,

undulation of pressure and temperature) satisfy condition of formula (A.32).

i N in (A.32) shall be determined according to A.4.3, in which a can be

calculated according to A.4.2.4, Stress range 2 can be determined according to the

following simplied method:

a) Working condition for pressure circulation of (include start-up, boiler shutdown):

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]3[a (A.1)

Where:

][ - When medium temperature of boiler barrel reach maximum under such cycle

working condition, permissible stress of barrel body material

Note: ][ Shall be selected according to provisions of this standard.

b) for cycle working condition that predictable pressure variation range p is no less

than 20% of design pressure s p :

][3s

a

p

p (A.2)

c) For thermosiphon working condition that temperature difference 1t between

radial inside and outside walls of barrel body is no less than 20℃:

111a 2 t E (A.3)

d) For thermosiphon working condition that circumferential temperature difference

2t of barrel body outside wall is no less than: for thermosiphon working condition

that temperature difference 1t between walls of barrel body is no less than 40℃:

211a t E (A.4)

In formula (A.3) and (A.4):

1 E - Elastic modulus of barrel body material under such working condition under

uniform wall temperature, unit is MPa;

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1 - linear expansibility of barrel body material under such working condition under

uniform wall temperature, unit is negative first power degree centigrade(1/℃).

If formula (A.32) is not satisfied, then it is required to conduct low cycle fatigue lifecalculation with under mentioned methods.

A.2 Examination, examination point and working condition working condition

A.2.1 Examination load

Examination load in this calculation method include pressure load of boiler barrel

media, radial temperature difference load along direction of boiler barrel body

thickness as well as temperature difference load along circumferential of boiler barrel

body.

A.2.2 Examination point

Examination point of this calculation method is section A of connector's reentrant

angle on axial section of boiler barrel body as showed in figure A.1

A.2.3 Matching for working condition

According to units operating mode to determine matching of cycle working condition

A.3 Stress calculation of examination point

A.3.1 Several explains

A.3.1.1 stress calculation in this method is conducted based on linear elasticity.

A.3.1.2 during stress calculation, presume that examination point has no change in

loads cycle along direction of principal stress

A.3.1.3 During stress calculation, stress exponent can use recommended value offered

by this method, also can adopt actual value acquired through test or numerical

calculation.

A.3.1.4 for each cycle working condition, it is only required to calculate peak and

valley stress under such working condition.

A.3.1.5 when calculate peak (valley) value stress under given cycle working condition,

linear expansibility , elastic modulus E and thermal diffusivity shall take value

according to maximum (minimum) medium temperature under such working

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condition.

A.3.2 Internal pressure stress

A.3.2.1 three principal stress component aroused by internal pressure at examination point shall be calculated according to formula (A.5)~( A.7) (stress component

direction n, z, and r are showed in figure A.2):

dn1np K (A.5)

dz1zp k (A.6)

dr 1rp K (A.7)

Where:

np - Hoop stress component of examination point, unit is MPa;

zp - Axial stress component of examination point, unit is MPa. it is tangential stress

component of inner contour line of axial cross section at examination point for

structural shape showed in figure A.1.e)

rp - Normal stress component of examination point, unit is MPa;

1n K - Hoop stress indices aroused by internal pressure;

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1z K - Axial stress indices aroused by internal pressure, it is tangential stress indices

of inner contour line of axial cross section at examination point for structural shape

showed in figure A.1.e)

1r K - Normal stress indices aroused by internal pressure;

d - Membrane stress strength of boiler barrel body, unit is MPa.

A.3.2.2 Membrane stress strength of boiler barrel body d shall be calculated

according to formula (A.8):

2

y

yn

d2

p D

(A.8)

Where:

n D - Inside diameter of barrel body, unit is millimeter(mm);

y - Effective thickness of barrel body [ determined according to formula (13)], unit

is millimeter(mm);

z p - Under given cycle working condition, maximum and minimum operating

pressure of boiler barrel media, unit is MPa.

A.3.2.3 For connector type showed in figure A.1, refer to table A.1 for recommended

value of internal pressure stress indices of examination point section A

Table A.1 Internal pressure stress indices of examination point

Structural shapeInternal pressure stress indices

Figure A.1 a)~d) Figure A.1 e)

1n K 3.1 2.5

1z K -0.2 0.5

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1r K yn

y2

D

yn

y2

D

A.3.3 Radial temperature difference heat stress

A.3.3.1 It is presumed that:

a) Temperature field of boiler barrel body distribute as axial symmetry in hoop stress

section, and stable along axial direction of barrel body.

b) Inside wall temperature of boiler barrel body shall be taken as medium temperature,

and outside wall is heat-insulated.

A.3.3.2 calculation for temperature difference between radial inside and outside wallof boiler barrel body:

)1(/

2

nw1

jt

ea

vt t t

(A.9)

If |||| j1 vt t ＞ , then:

j1 vt t (A.10)

Where:

wt - Outside wall temperature of barrel body, unit is degree centigrade(℃).

nt - Inside wall temperature of barrel body, unit is degree centigrade(℃).

- Structural coefficient, can be taken from figure A.3. in figure is radio of

outside diameter w D and inside diameter n D

- Nominal thickness of barrel body, unit is millimeter(mm).

v - Rate of change of medium temperature in boiler barrel, unit is degree centigrade

per minute (℃/min).When calculate valley value, v Shall take average heating-up

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velocity (positive value) at initial stage of start-up (or load up); When calculate peak

stress, v shall take average cooling rate (negative) at initial stage of boiler shutdown

(or load down).

jt - Duration of medium temperature in boiler barrel rise (fall) at velocity of v, unit is

minute(min).

- Damping coefficient of temperature, taken with figure A.4.

t - Time constant, )16/(2

n a Dt , unit is minute(min).

a - Thermal diffusivity of barrel body material, unit is square millimeter per minute.

e - Base of natural logarithm

A.3.3.3 Radial temperature difference heat stress shall be calculated according to the

following formula:

Hoop heat stress:

1n2nt)1(

t f

aE K

(A.11)

Axial heat stress:

(A.12)

Normal heat stress:

0zt (A.13)

Where:

2nK - Hoop heat stress indices aroused by radial temperature difference. Its value is

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ratio of hoop heat stress aroused by radial temperature difference at examination point

and ideal solution to hoop heat stress of inside wall of imperforate barrel body. it is

recommended to take 6.12n K .

2z K - Axial heat stress indices aroused by radial temperature difference. Its value is

ratio of axial heat stress aroused by radial temperature difference at examination point

[it is tangential for structural shape of figure A.1e)] and ideal solution to axial heat

stress of inside wall of imperforate barrel body. It is recommended to take 6.1z2 K

a - Linear expansibility of barrel body material, unit is negative first power degree

centigrade(1/℃).

E - Unisexual module of barrel body material, unit is MPa.

- Poisson ratio of barrel body material, 3.0 .

f - Structural coefficient, taken with figure A.3.

A.3.4 Circumferential temperature difference heat stress

Circumferential temperature difference heat stress shall be calculated according to the

following formula:

Hoop heat stress:

max3nTz t BaE K (A.14)

Axial heat stress:

(A.15)

Normal heat stress:

0zT (A.16)

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Where:

3n K - Hoop heat stress indices aroused by circumferential temperature difference. Its

value is defined as ratio of hoop stress aroused by circumferential temperaturedifference at examination point and “ max4.0 t aE ”.It is recommended to

take 1n3 K .

3z K - Axial heat stress indices aroused by circumferential temperature difference. Its

value is defined as ratio of axial [tangential for structural shape showed in figure

A.1.e)] heat stress aroused by circumferential temperature difference

and“ max4.0 t aE ”.It is recommended to take 1z3 K .

B - Coefficient, take 0.4.

maxt - Maximum circumferential temperature difference of outside wall, unit is

degree centigrade(℃).For a certain cycle working condition, when calculate valley,

peak stress, maxt Shall respectively take maximum temperature difference between

upper and lower wall at initial stage of start-up or load up, boiler shutdown or load

down. If this temperature difference is difficult to determine, maxt shall take 40℃

when calculate valley stress, maxt shall take 10℃ when calculate peak stress.

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A.3.5 Synthesized principal stress

Synthesized principal stress aroused by internal pressure and temperature difference

shall be calculated according to the following formula:

nTnLnp1 (A.17)

zTzLzp2 (A.18)

rTrLrp3 (A.19)

Where:

1 - Hoop synthesized principal stress at examination point, unit is MPa;

2 - Axial synthesized principal stress at examination point[it is tangential for

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structural shape of figure A.1 e)], unit is MPa;

3 - Normal synthesized principal stress at examination point, unit is MPa.

Synthesized principal stress in formula (A.17)~formula (A.19) shall be calculated by

taking extreme value of internal pressure stress and heat stress; and the result is

conservative. If required, it is allowed to calculate with value of internal pressure

stress and heat stress at the same time.

A.4 Calculation for low cycle fatigue life under given cycle working condition

A.4.1 principal stress difference

Use )321(, gifi 、、i To mark calculated value of peak, valley principal stress,

After working out peak, valley principal stress under such working condition

according to those specified in A.3.2 ~ A.3.5 fi and gi , Principal stress difference

can be calculated according to the following formula.

A.4.1.1 Principal stress difference of peak value shall be calculated according to the

following formula:

f21f 2f1 (A.20)

f32f 3f2 (A.21)

f13f 1f3 (A.22)

A.4.1.2 Principal stress difference of valley value shall be calculated according to thefollowing formula:

g2g12g1 (A.23)

g3g23g2 (A.24)

g1g31g3 (A.25)

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A.4.2 Variation range of principal stress difference, scope of alternate stress and stress

range

A.4.2.1 Variation range of principal stress difference shall be calculated according to

the following formula:

g1212f 12 (A.26)

23g23f 23 (A.27)

31g31f 31 (A.28)

A.4.2.2 Scope of alternate stress shall be calculated according to formula (A.29):

}max{ 312312 ，， (A.29)

A.4.2.3 Stress range shall be calculated according to formula (A.30):

2/a (A.30)

A.4.2.4 Modified stress range shall be calculated according to formula (A.31):

L E

E 0aa (A.31)

Where:

0 E - Elastic model given in curve of low cycle fatigue (figure A.5),

MPa1006.2 5

0 E ;

L E - Elastic modulus of material at examination point at maximum medium

temperature under such working condition, unit is MPa.

A.4.3 Permissible cycle index

Use a value to look up value N on low cycle fatigue design curve (figure A.5), N

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represents permissible cycle index of this working condition.

A.5 Safety criterion for cumulative damage

Safety criterion for cumulative damage is:

m

i i

i

N

n

1

1≤ (A.32)

Where:

m - Cumulative number of different cycle working condition;

in - Anticipated cycle index during designed life under given cycle working

condition;

i N - Permissible cycle index calculated under given cycle working condition.

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Appendix B

(Informative appendix)

Elementary permissible stress of overseas material under different designtemperature J ][

Table B.1 Elementary permissible stress of overseas material under different

design temperature J ][

unit is MPa

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Steel grade and

number

of

standard S A - 1 0 6 B

A S M E S A - 1 0 6

S A - 2 1 0 C

S A M E S A - 2 1 0

1 5 M o 3

D I N 1 7 1 7 5

S A - 2 0 9 T 1 a

A S M E S A - 2 0 9

T 1 2

A S M E S A - 2 1 3

T 2 2

A S M E S A - 2 1 3

T 9 1 / P 9 1

A S M E S

A - 2 1 3 / S

T P 3 0 4 H

A S M E S A - 2 1 3

T P 3 4 7 H

A S M E S A - 2 1 3

1 5 N i C u M N b 5 -

6 - 4

E N 1 0 0 2 1 6

T 2 3

A S M E

Thickness of steel plate/mm

s 240 275 270 220 220 280 415 205 205 440 400

b 415 485 450 415 415 450 585 520 520 610 510

20 153 180 167 147 147 167 247 137 137 244 189

250 132 151 116 125 126 124 198 113 131 224

260 131 150 115 124 115 124 198 111 130 223

270 130 148 114 123 115 124 198 110 129 222

280 128 147 113 123 114 124 198 109 128 221

290 127 145 112 122 114 124 198 108 126 219

300 125 144 111 121 113 124 198 107 125 218

310 124 142 110 121 112 124 198 106 124 217

320 123 140 109 120 112 124 197 105 123 216

330 121 138 108 119 111 124 197 105 122 215

340 120 137 107 118 111 124 196 104 122 214

350 115 135 106 118 110 124 195 103 121 213

360 112 130 106 117 109 124 194 102 120 210

370 108 127 105 116 109 124 193 101 119 206

d

e

s

i

g

n

t

e

p

e

r

a380 102 118 105 115 108 123 192 100 119 203

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390 95 110 104 114 108 123 190 100 118 199

400 89 101 104 113 107 123 188 99 118 196

410 84 94 103 112 105 123 186 98 117 192

420 78 87 102 111 106 122 184 98 117 187

430 73 81 102 109 105 122 182 97 117 183

440 68 74 101 108 104 121 180 96 116 178

450 62 67 100 107 103 116 177 95 116 163

460 56 61 99 104 102 110 174 94 116 140

470 49 54 99 100 101 103 171 94 115 117

480 42 48 94 95 100 95 168 93 115 93

490 83 84 94 88 165 93 115 69

500 68 70 86 81 161 92 115 46

510 55 57 78 74 156 91 114 123

520 43 48 68 68 138 91 114 114

530 58 61 124 90 113 105

t

u

r

e

bit /

℃

540 48 54 111 89 113 97

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Table B.1(continue)

Steel grade and

number of

standard

S A - 1 0 6 B

A S M E -

S A M E

1 5 M o 3

D I N 1 7 1 7 5

S A - 2 0 9 T 1 a

A S M E

T 1 2

A S M E

T 2 2

A S M E S

A - 2 1 3

T 9 1 / P 9 1

A S M E

T P 3 0 4 H

A S M E

T P 3 4 7 H

A S M E

1 5 N i C u M N b

5 - 6 - 4

E N 1 0 0 2 1 6

T 2 3

A S M E

Thickness of steel

plate/mm

s 240 275 270 220 220 280 415 205 205 440 400

b 415 485 450 415 415 450 585 520 520 610 510

550 41 48 105

(10

2)

88 112 89

560 35 42 100 (94) 88 112 81

570 29 37 92 (85) 83 109 74

580 25 32 83 (77) 76 104 67

590 74 (69) 70 99 60

600 66 (62) 64 91 53

610 57 (55) 59 92 46

620 49 54 73 39

630 42 50 67

640 36 46 60

Design

te

mp

era

tur

e

bit /℃

650 30 42 54

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660 38 49

670 35 44

680 32 39

690 29 36

700 27 32

710

720

Note: Data under thick line shall be calculated as long-time strength D , Temperature corresponds to this data.

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Appendix C

(Informative appendix)

Approximate calculation for W bending resistance section factor of open pore

weaken cross section

C.1 Signification and unit of signs used in this appendix are as follows;

- Thickness of boiler barrel body or header tank body, mm;

w D - Outside diameter of boiler barrel body or header tank body mm;

n D - Inside diameter of boiler barrel body or header tank body, mm;

p R - Average radius of boiler barrel body or header tank body, mm;

i D - Diameter of pore(i=1, 2, 3……), mm;

i - Separation angle between pore central line and horizontal central axis of boiler

barrel body or header tank body X-X(i=1, 2, 3……);

x I - Processional moment of open pore weakened cross section to centerline X-X,

4mm ;

1x I - Processional moment of open pore weakened cross section to

centerline 11 X X — , 4mm ;

xS - Statical moment of pore to centerline X-X, 3mm ;

A - Area of open pore weaken cross-section, 2mm ;

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c y - Vertical distance between open pore weaken cross section and centerline X - X,

mm;

xW - Bending resistance section factor of open pore weaken cross section to

centerline X-X, 3mm ;

xdi I - Processional moment of pore id in open pore weakened cross section to

centerline X-X, 4mm ;

1xW - Bending resistance section factor of open pore weaken cross section to

centerline 11 X X — , " bending resistance section factor " for short, 3mm .

Note: refer to figure C.1 for value-taking method ii， ad .

C.2 Computing formula for bending resistance section factor of open pore


Bending resistance section factor of open pore weakened cross section shall be

calculated according to the following formula:

cw

1xx1

2/ y D

I W

(C.1)

Where:

i

2

n

2

w

ii pxc

4/)(

sin

d D D

d R

A

S

y

(C.2)

A y I D D A y I I 2

cxdi

4

n

4

w

2

cxx1 )(64

iii

i Rd d d

D D

22

p

23

i

23

i4

n

4

w sinsin12

cos12

)(64

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146

id D D y

)(4

2

n

2

w

2

c (C.3)

C.3 Proximate calculation for bending resistance section factor of open pore


C.3.1 Processional moment

ii Rd D D I I 22

p

4

n

4

wx1x sin)(64

(C.4)

Neglected during calculation

i

ii

i d d 23

23

sin12

cos12

7/25/2019 GBT 9222-2008


And

id D D y

)(4

2

n

3

w

2

c

C.3.2 Bending resistance section factor

Under the condition that open pore weaken condition of upper and lower halves on

horizontal axis of cross section X - X, are similar, c y Is extremely small and can be

ignored(it is considered that centerline X - X and 11 X X — coincide with each other,

namely 0c

y ), Therefore, bending resistance section factor can be approximately

calculated according to formula (C.5):

2/w

xx1x

D

I W W (C.5)

When open pore weaken condition centre on one side of horizontal axis of cross

section, influence of c y must be considered, then, bending resistance section factor

shall be calculated approximately according to formula (C 6):

gbt 9222-2008

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