piping pipe supports technical requirements guideline

PIPE SUPPORTS

TECHNICAL REQUIREMENTS GUIDELINE

>>Standard<<

1 Upraveno 06/2009 KRI 0 Původní vyhotovení 04/2001 KRI Index Popis změny Date Elaborated Date Revised by

Dok. č.: ISZ-01 Project: Pipe support standard Page: 1 / 23 GRADIOR POWER s.r.o., Křižíkova 68, 660 90 Brno, DIČ: CZ25310003 tel.: +420 538 717 800, fax: +420 538 717 801, email: [email protected], www.gradior.cz/power Ev.č. 22/0

CONTENTS

1. OBJECTIVES ................................................................................................................. 2

2. SCOPE ........................................................................................................................... 2

3. PIPE CATEGORIZATION AND PIPE SUPPORTS CLASSES ........................................ 3

4. DESIGN PROCESS ....................................................................................................... 4

4.1 General principles ................................................................................................... 4

4.2 Requirements for spring hangers and supports ....................................................... 5

4.3 Further requirements for hangers and supports ...................................................... 5

4.4 Pipe connection ...................................................................................................... 6

4.5 Attachment to structure ........................................................................................... 7

5. REQUIREMENTS FOR CONSTRUCTION ..................................................................... 8

5.1 General requirements for construction arrangement ............................................... 8

5.2 Weld joints .............................................................................................................. 8

5.3 Connecting elements .............................................................................................. 8

5.4 Rigid components of pipe supports ......................................................................... 8

5.5 Pipe surrounding construction parts ........................................................................ 9

5.6 Spring hangers, spring supports ............................................................................. 9

5.7 Constant hangers and supports .............................................................................. 9

5.8 Rigid struts ............................................................................................................ 10

5.9 Shock absorbers ................................................................................................... 11

5.10 Sliding supports and guides .................................................................................. 11

6 LOAD AND ALLOWABLE STRESS CALCULATION .................................................... 12

6.1 Load ...................................................................................................................... 12

6.2 Permissible load.................................................................................................... 12

6.3 Stress evaluation .................................................................................................. 12

6.4 Experimental realization of permissible load ......................................................... 14

7 MATERIALS ................................................................................................................. 15

8 INSPECTIONS AND TESTING..................................................................................... 18

8.1. Fabrication tests.................................................................................................... 18

8.2. Final inspection – standard catalog hangers and supports .................................... 18

8.3. Standard spring and constant supports ................................................................. 18

8.4. Pipe supports without catalog type ........................................................................ 19

8.5. On-site tests .......................................................................................................... 20

8.6. Repetitive tests ..................................................................................................... 21

9 DOCUMENTATION ...................................................................................................... 22

10 RELATED STANDARDS .............................................................................................. 23

No.: ISZ-01 Project: Pipe support standard Index: 1 Page: 2 / 23

1. OBJECTIVES Basic objective of this guideline is to define uniform technical requirements for pipe

supports, which is standard manufactured commodity. Uniform and to all engaged parts well-known standards are important instrument for enhancement of efficiency and technical performance of design, fabrication, installation and operation. Currently there is no uniform industry standard existing to be complexly concerned with this issue.

This guideline defines basic technical and design requirements for industrial piping

support. Guideline consists of “design” part, which describes basic principles for design concept of pipe supports, and of “fabrication” part which establishes criteria for pipe supports manufacturers – design principles, dimensioning and material requirements.

This guideline is based on standards EN 13480-3, VGB R-510L, MSS-SP58, ASME

B31.1, KTA 3205.3 and ČSN 130021-5.1.

2. SCOPE

This guideline relates to pipe supports for thermal and nuclear power plants, chemical and petrochemical facilities and for gas transport piping, in operational temperature range from –20°C to 600°C. For temperatures below –20°C it is necessary to consider further criteria according to EN 13480-2 standard.

This guideline relates to:

Rigid and spring hangers assemblies

Pipe saddle supports

Components of pipe supports assemblies, like as:

− Spring supports

− Clamps, U-bolts, other parts in contact with piping

− Connecting elements of hangers – hanger rods, eyenuts,

clevises, turnbuckles

− Beams and trapezes

− Rigid struts

Guideline is elaborated on base of above mentioned standards, extended with further

requirements of pipe supports manufacturers and piping operators. List of requirements defined in this guideline is not exhaustive, and

guideline is valid mainly in conjunction with standard EN 13480-3. Requirements of standard EN 13480-3, not mentioned in guideline, are valid. Exception is in section 7, where use of materials different from EN 13480-2 is allowed.


3. PIPE CATEGORIZATION AND PIPE SUPPORTS CLASSES

Pipe supports are classified into three categories, in dependence on supported pipe category and pressure equipment (acc. to EN 13480 – 1, section 4):

Chart.1. Pipe supports classification

Pipe category Support class III S3 II S2

I and 0 S1

Requirements for fabrication, checking and documentation are graduated for individual pipe support classes. Requirements of each pipe class are defined in individual sections.


4. DESIGN PROCESS

4.1 General principles 4.1.1 Piping designer is responsible for supports concept, project elaboration and design of

auxiliary structures for piping attachment. 4.1.2 Documentation delivered by manufacturer must contain load data, movement data

and bill of materials. Every design drawing must contain all data necessary for installation. Some standard rigid supports of S1 class (supports, U-bolts etc.), supplied assembled, can be documented just by catalog sheet.

4.1.3 Pipe supports or support structures must not reduce the underpass height under 2.2 m in passage areas.

4.1.4 Selection and arrangement of pipe supports:

− recommended distances of pipe supports placement defined by formula: 400 DN⋅

− pipe supports shall be placed in proximity to concentrated mass, e.g. fittings, flanges

− support shall be placed in proximity to change of piping direction, i.e. branches, elbows

− support placement on vertical piping – rigid hanger preferably between centre and upper third of pipe (to assure stability), intermediate guide

− use utmost of side guides to clearly define the pipe movement

− first hanger or support before the pump connection must be height adjustable

− supports on pipe racks should be height adjustable to keep the pipe slope

4.1.5 For auxiliary and support structures applies criteria according to regulations for steel structures – EN 1993.

4.1.6 In case of sliding supports it must be ensured that after long-lasting operation would not be exceeded calculated values of friction forces. Rigid support is as default designed for friction coefficient 0.3 (rust steel-steel).

4.1.7 Rod hangers must be executed to ensure free movement between two hinges. For pipes DN≥80 they must be equipped with stretching element for leveling or additional adjustment during piping operation. Lengthening of hanger rods shall be executed by bolt elements, welding of hanger rods is not permitted.

4.1.8 Pipe supports including auxiliary and support structures shall be executed to prevent accumulating of water in corners, edges and cavities.

4.1.9 For ease of construction and installation the standard pipe supports shall be preferred over individual constructions.

4.1.10 Heat transfer form pipe through pipe support to building structure should be as low as possible. Special attention must be paid to parts welded to pipe with regard to plastic deformations and stress from temperature and limited deformations.


4.2 Requirements for spring hangers and supports 4.2.1 For compensation of vertical dilation movements up to 50mm can be used spring

hangers / supports if the relative load variation between cold and hot load will not exceed 25% - related to hot load (1). For higher movement values or load variations, the constant hangers / supports shall be used.

25.0≤−

H

CH

F

FF (1)

4.2.2 Spring type (travel/rate) is selected by evaluation of relative and absolute load variation and according to construction length requirements. Upon use of spring of higher travel and lower spring rate the relative load variation decreases. For example, for spring of type FN=4000 N / sN=150 mm and movement 25 mm is the relative load variation 17%, for spring of type FN=4000 N / sN=250 mm variation amounts 10%.

4.2.3 Upon determination of value FC the weight of all flexible hanger / support elements must be added to FVC load value.

4.2.4 Spring travel reserves

a) Upon selection of spring hangers / supports must be spring travel reserve taken into consideration. For constant hangers, necessary reserve amounts 10% of calculated movement, but at least 10 mm to each end position. For spring hangers, necessary reserve amounts 20% of calculated movement, but at least 5 mm.

b) For constant hangers and supports must be available additional load variation in range of ± 15 % regarding to set load value, without restraining travel reserve.

c) Spring hangers of class S2 and S3 must be factory set to cold load and locked to prevent movements in both directions. Constant hangers of all classes are always locked in cold load position. Locking of class S1 supports must be specified in order.

4.3 Further requirements for hangers and supports

Horizontal forces and movements, hanger deviation 4.3.1 Hangers are preferably set in vertical position during installation. 4.3.2 At hanger rods the angular deviation in operational conditions must not exceed 4°

from perpendicular axis. 4.3.3 Double rod hanger for horizontal movements, which causes deviation over 2.5° in

hanger rods level shall be attached to structure in single point. 4.3.4 For spring and constant supports must be horizontal forces, caused by side

movement, restrained to less than 7% of main vertical load by appropriate measure-ment (sliding PTFE plates, guides etc.).

4.3.5 Spring and constant supports shall be placed in accessible position to allow adjust-ment check after installation.

4.3.6 At shock absorber selection the travel reserve must be taken into consideration. Necessary reserve amounts 10% of calculated movement, but at least 25 mm to each end position.

4.3.7 Sliding supports movement reserve shall be at least 25 mm and bearing structure base shall conform to this requirement.


4.3.8 Operational and construction temperatures Construction temperatures of pipe support elements are defined by undermentioned relations and figure 1:

Elements inside insulation

for parts with direct contact to pipe wall: T = Tf

for parts without direct contact to pipe wall: T = Tf – 20 °C

for bolts and nuts: T = Tf – 30 °C

Elements outside insulation

directly consecutive parts:

T = max {0,5 x (Tf – 10 °C); 80 °C},

For consecutive pins or bolts and nuts for sliding supports:

T = max {0,33 x (Tf – 10 °C); 80 °C}

Figure 1. Construction temperature of pipe support elements

TM

max [0,33*(TM-10°C), 80°C]

TM - 30 °CTM - 20 °C

max [0,5*(TM-10°C), 80°C]

max [0,33*(TM-10°C), 80°C]

4.4 Pipe connection 4.4.1 Pipe support shall be executed to prevent relative movement between pressure pipe

wall and pipe surrounding component, which could damage pipe wall by abrasion. 4.4.2 It is recommended to tie pipes with clamps to avoid plastic deformations of pipe wall

in load transfer area:

− Pipe class 0 and 1

− Pipe class 2 and 3 – circular pivot lugs and flat lugs of vertical hangers or fix points and guides. Welds on alloy steel pipes class 2 and 3 must be grinded without dents and arranged to be accessible for non-destructive testing. During construction the temperature gradient must be respected. Application must be documented by calculation.

4.4.3 For pipe supports class S2 and S3 and temperatures Tf > 100 °C are U-bolts with line contact is not permitted. For pipe supports class 1 and temperatures above 100°C, U-bolts may be used only for pipes DN<150 and Tf < 300°C and further at absence of axial forces from piping.


4.4.4 Pro lowering of stress concentration on pressure pipe walls, for pipes of operational temperatures above 500°C and outer diameter ≥ 168.3 mm are used fully-welded circular pivot lugs.

4.4.5 Weld-on supports are used preferably for non-insulated outdoor pipes. 4.4.6 For guide in sliding supports must be sufficient movement clearance for operational

condition taken into account. If not stated else in documentation (clearance for various temperature expansion), sufficient clearance amounts 2 mm. For outdoor use or in dusty environment it is necessary to protect slide surfaces against pollution. Position of slide surfaces must be properly secured. Special sliding materials (coat, PTFE) can be used only if degradation of their properties due to heat transfer and radiation, pollution or other operational influences can be avoided.

4.4.7 Welded lugs / shoes must be executed that pipe clamps adjoins to lug by plain surface and never to surface of the weld. Clearance between clamps and lugs shall not be too wide.

4.4.8 At insulated pipes, the fastening bolts must not stick out of insulation. 4.4.9 On vertical pipes, fix points and pipe guides of outer diameter D≥ 88.9 mm it is

necessary to lock the clamp or U-bolt against shifting by welding stop lugs.

4.5 Attachment to structure 4.5.1 Attachment to steel structure

− attachment on stanchions or beams of sufficient size or on beams without other load − attachment on stanchions or beams in proximity to main joints to minimize of

bending stress − avoid to load which causes torsion or eccentric movement. For pipes of outer

diameter ≤ 88.9 mm, verifying by calculation is not required − do not attach to secondary equipment (ventilation) and elements in danger of loss

strut stability − fix points and restrain of rigid piping movement perform preferentially on the same

structure of tie together several structures − perform position and structure load check by organization responsible for project of

construction 4.5.2 Concrete anchors

They should be used scarcely. Can be used attachment instruments with type certificate only. Conditions stated in affirmation certificate must be fulfilled. Anchor joints must consist of larger amount of anchors, use of single anchor per anchor plate is not allowed.

4.5.3 Attachment on concrete pillars:

If console attachment on reinforced concrete pillars by anchor plates is not possible, the pillar can be embraced by steel profile with pulling anchor. Structure shall be eventually secured against shifting or sliding.

4.5.4 Attachment on walls

Consoles attached on brick or concrete walls without reinforcing must be equipped with through pulling anchors and sufficiently dimensioned bearing plate on opposite wall surface.


5. REQUIREMENTS FOR CONSTRUCTION

5.1 General requirements for construction arrangeme nt 5.1.1 Standard pipe supports shall be designed as a maintenance-free for normal

operational conditions. Supports operational life must at least correspond to operational life of piping and its components. If not given else, operational life accounts for 200.000 hours as default. Periodical inspections of pipe support condition shall be performed in 24 months intervals.

5.1.2 All pipe supports except hydraulic shock absorbers shall be designed for temperatures at least 80 °C.

5.1.3 Hanger rods of double rod horizontal pipe hangers must be dimensioned to bear entire hanger load. Dimensioning of hanger rods of double rod vertical pipe hangers shall be performed with respect to pipe attachment construction. According to clamp and lug construction ability of load equalization it is possible to choose load of single rod in range (0.5 – 1) x entire hanger load.

5.1.4 Roller bearings must be equipped with sliding bushing or ball bearings. 5.1.5 For compression stressed pipe supports is permissible slenderness ratio λ ≤ 150. 5.1.6 Cold-bended parts must comply with requirements for minimum bend radiuses

according to relevant material standards. 5.1.7 Surfaces of standard pipe supports shall allow performing of decontamination.

5.2 Weld joints 5.2.1 Double side welds are preferred to single side welds. Single fillet welds are permiss-

ible, if such welded joints transfer any local bending moment in weld mass direction. This condition is accomplished for example if parts are welded by circumferential weld.

5.2.2 Single layer weld joints in force flow are permissible for weld thickness a ≤ 6 mm.

5.3 Connecting elements 5.3.1 Bolts may be in threaded part stressed only by compression, not by bending.

Maximum permissible deviation of joint contact surface parallelism is ±1°. 5.3.2 Bolt joints of pipe support must be locked against loosening. Allowable arrangements

are: safety metal sheets and safety nuts, only in some cases controlled preload. 5.3.3 Length of engaged thread must amount at least 0.8 x nominal thread diameter. 5.3.4 Minimum length of thread engagement must be controllable. 5.3.5 For pin joints, the pins must be locked by washers and splits. Snap rings are

permitted only if clearance between pin and hole amounts less than 0.5 mm. 5.3.6 Welded clevises and eyes must be NDT tested on weld depth, cold joints and internal

defects. Weld defects evaluation class C. 5.3.7 Replacement of clevis by couple of pins and liners is not permitted. 5.3.8 Use of welded connection eyes is exceptionally permitted for carbon steels up to

hanger rod diameter 24mm.

5.4 Rigid components of pipe supports 5.4.1 For standard pipe supports class S2 and S3 from steel materials must not be

exceeded following minimal dimensions (material thickness): a) Weld-on eyes and lugs 8 mm b) Clamps 5 mm c) Weld-on plates 8 mm d) Threaded rods 12 mm (For pipe of outer diameter ≤ 60.3 mm is allowed 10 mm after supplier’s agreement.)

5.4.2 At cold forming of carbon and low-alloyed steels, minimum bend radiuses according to EN 10 025 must be respected.


5.5 Pipe surrounding construction parts 5.5.1 Clamps geometry must be chosen with respect to pipe and clamp tolerations so the

clamps contact surfaces are parallel after installation. 5.5.2 Sharp edges of clamps on pipe contact side must be seamed. 5.5.3 Pipe clamps can be cold or hot formed. Cold bended may be only parts with relative

deformation less than 30%. For relative deformation in % applies: 50*t/rm, where t = thickness of material, rm = medium sheet bend radius.

5.5.4 At cold forming of austenitic steels, minimum bend radiuses of 1.0 x thickness of material must be respected. In other case hot forming and treating must be used for fabrication.

5.5.5 Metal sheets put between pipe and clamp must be fixed against shifting (e.g. by lining).

5.6 Spring hangers, spring supports 5.6.1 Spring hangers must be due to force transfer and spring protection equipped with

properly shaped casing (cage). Application of control holes is suitable. Casing must be created in shape that allows free outflow of rainwater or water from pipe leaks. In case of necessity a special anti-dust protection shall be settled in order.

5.6.2 Spring dishes must be executed and centered to prevent friction between spring and case.

5.6.3 May be used only heat treated helical spring resistible to relaxation and with shot peened surface. After 48-hours load FN at 80 °C the relaxation may not exceed ±2.5 %.

5.6.4 Horizontal flexibility of spring hangers on beams must be at least 4° of hanger rod deviation.

5.6.5 Vertically loaded spring hangers and supports in blocked position must be able to bear at least 2,5 x FN without any plastic deformation.

5.6.6 Spring supports must be dimensioned on horizontal forces up to 7 % of vertical load. 5.6.7 For vertical compression or tension force must not be exceeded the real load

deviation for more than 5% of theoretic spring load in assumed hanger lift. 5.6.8 For forces in slant tension 4° or cross tensi on amounting 7 % of vertical load in

compression of spring support must not be exceeded the real load deviation for more than 6 % of theoretic spring load in assumed hanger lift.

5.6.9 In nominal travel range must be possible to fix spring hanger and support in any variable position, also additionally (e.g. on building site).

5.6.10 Inside construction parts must not cause blocking even at maximum slant tension (4°).

5.6.11 For spring hangers must be ensured that their working travel lies within linear spring load range.

5.6.12 Spring hanger beams and lugs may be welded to spring case before spring insertion only. Violation of this condition is possible only if proper measures are executed to provably prevent negative effects on spring.

5.7 Constant hangers and supports 5.7.1 Movement in main load direction must be 4° as minimum. 5.7.2 Vertically loaded constant hangers and supports in fixed position must be able to bear

at least 2.5 x FN load without any permanent deformation. 5.7.3 Constant supports must be dimensioned to horizontal loads up to 7 % of vertical load. 5.7.4 For vertical tension or compression load must not be exceeded the real load deviation

for more than 5 % of theoretic spring load in assumed hanger lift. 5.7.5 For forces in slant tension 4° or cross tensi on amounting 7 % of vertical load in

compression of spring support must not be exceeded the real load deviation for more than 6 % of theoretic spring load in assumed hanger lift.

5.7.6 Maximum deviation of real load median must be lower than 2 % of theoretic load.


5.7.7 Constant hangers must be due to force transfer and spring protection equipped with properly shaped casing (cage). Application of control holes is suitable. Casing must be created in shape that allows free outflow of rainwater or water from pipe leaks.

5.7.8 May be used only heat treated helical spring resistible to relaxation and with shot peened surface. After 48-hours load FN at 80 °C the relaxation may not exceed ±2.5 %.

5.7.9 Constant hangers must be equipped with end stops or suitable construction elements for spring protection.

5.7.10 In nominal travel range sN must be possible to fix constant hangers and supports in any variable position, also additionally (e.g. on building site).

5.7.11 Fixation elements must be situated on easily accessible place of case. 5.7.12 Inside construction parts must not cause blocking even at maximum slant tension

(4°). 5.7.13 Spring hanger beams and lugs may be welded to spring case before spring insertion

only. Violation of this condition is possible only if proper measures are executed to provably prevent negative effects on spring.

5.8 Rigid struts 5.8.1 Rigid struts must be dimensioned to alternate load spectrum according to Table 2 for

compression and tension at 80 °C. Designed temperat ure for connection elements is 150 °C.

5.8.2 For adjustable rigid struts must be length adjustable in minimum range ± 25 mm for all types and sizes in operational position. Maximum allowable length adjustment (ball bushing joint engagement) must be visibly marked to ensure minimum engagement.

5.8.3 Ball bushings must allow 6° deviation. Ball b ushing joints must be locked without clearance. In case of counter nut application, fine pitch thread must be used.

5.8.4 Eccentricity u0 between joint bearings and strut axis must not exceed 1 mm for lengths ≤ 1000 mm. For lengths > 1000 mm may reach at maximum L/1000 (Fig. 2). Table 2. Alternate load cycles for rigid struts Load Number of cycles

1,5 x FN 25 1,0 x FN 3 300 0,5 x FN 47 000 0,1 x FN 330 000

Fig. 2. Adjustable rigid strut

Hlava kloubu

max. L

Prodlužovací trubka

uo

max. L / 2

5.8.5 Total clearance of rigid struts including their connection parts at use of pins or fitted

bolts up to diameter 33 mm shall not exceed 0.5 mm, for larger diameters shall not exceed 1.5 % of pin diameter.

Ball bushing joint Strut body


5.8.6 Clamps for rigid struts must be dimensioned in accordance to their use and for cyclic load according to Table 2.

5.9 Shock absorbers 5.9.1 Only hydraulic shock absorbers use is allowed. Mechanical shock absorbers may be

used only exceptionally, with purchaser’s approval. 5.9.2 Shock absorbers must not restrain pipe dilation movements during normal operational

conditions. 5.9.3 Shock absorbers must be placed in ball bushings with deviation allowance 6°. Total

permissible clearances are 1.5mm, including dead lift value. 5.9.4 Shock absorbers must be functional in any installation position. 5.9.5 Required shock absorbers operational characteristics are stated in Table 3.

Table 3. Shock absorbers operational characteristics Parameter Value Lockup velocity 3 – 5 mm/s Bypass velocity 0.2 – 2 mm/s Operational frequency band 0,5 – 50 Hz Frictional resistance 300N at FN < 15kN

0.02* FN at FN < 15kN Travel at load (20°C) 0.025*S N, max. 8mm

5.9.6 Travel setting must be visible from scale. Travel reserve of last 20mm must be visibly

indicated.

5.10 Sliding supports and guides 5.10.1 Supports must be designed to ensure permanent load transfer on pipe, in all

considerable operational conditions, regarding different temperatures of elements and temperature dilations.

5.10.2 During sliding support movement, regarding friction coefficient 0.3 between support and base structure, must not happen to support turnover due to relative slewing between clamp and pipe. This stability must be proved by calculation.

5.10.3 Use of common supports with side lugs as a axial guides must be proved.


6 LOAD AND ALLOWABLE STRESS CALCULATION

6.1 Load 6.1.1 Load categorization according to Table 4.

Table 4: Definition of load categories G, Q

Load

G Permanent load: all presumed loads and influences which do not occur only short-time.

Example: weight of pipe and content, dilation and other movement forces, preloading, forces from axial compensators, friction forces, snow load.

Q Sum of permanent and live load. Wind load, earthquake load.

Example: G + wind load, dynamic forces load at safety valve opening, earthquake.

6.1.2 For standard supports strained by slant tension or compression must be in

calculations considered side force action in resolution to permanent load direction.

6.2 Permissible load Permissible load must be proved by one of following three procedures: 6.2.1 By calculation (without supplementary experimental evaluation), if given geometry

can be computationally modeled. 6.2.2 By calculation supplemented by experimental test. This record is required when

element can be modeled only approximately. This applies among others to rigid struts, threaded eyes, turnbuckles etc. For selected design sizes, which represents whole application range, must be experimental tests executed.

6.2.3 Experimental tests without calculation for every parameter, e.g. dimension, material and direction of load.

6.2.4 These records must be executed reproducibly and must be documented.

6.3 Stress evaluation 6.3.1 Computed stresses must be compared with permissible stress values. Declaration of

permissible stresses is stated in following paragraphs. Stress values indexes: T - at computed temperature NT - at normal temperature

6.3.2 Material characteristics values are stated in standards according to chapter 7. If value RmT/200000 for given material is not known, value RmT/100000/1.5 can be used in calculation.

6.3.3 Permissible stress for statically stressed construction parts from specified materials a) Permissible stress f for ferritic steels according to EN:

= 200000/e

;5,1

R;

4,2min mT

HTmNTm R

RS (2)

b) If values ReH are not available, values Rp0,2 values shall be used. c) For steels S 235 and S 355 in temperature range 80 °C < T ≤ 350 °C is possible to

use permissible stress values with reduction factor K acc. to VGB R-510L fig.11. d) For austenitic steels with yield stress to tensile strength ratio ≤ 0.5 at 20 °C can be

used 1% yield stress Rp1,0T instead of Rp0,2/T.


e) For ferritic and austenitic cast steels is stress f calculated by equation (2) divided by 1.3 factor.

6.3.4 Permissible stress values for bolt joints a) For stress calculations in bolts applies following principles:

For evaluation of shear stress is crucial the diameter of stressed area (shank or core). For stress evaluation at tensile load for bolts with metric thread ISO is decisive the core cross section according to ISO 965.

b) Permissible stress Sm for bolt joints and threaded rods:

=4.1

000200/;

5.2

Rmin

e mTHTm

RS (3)

c) Bolts of strength class 4.6; 5.6; 8.8 a 10.9 may be dimensioned up to 80 °C according to DIN 18 800, section 1. For bolts of strength class 4.6 in temperature range 80 °C ≤ T < 350 °C applies same reduction factor as for ste el S 235 acc. to fig. 11 of VGB R-510L regulation. For bolt joints of strength class 5.6; 8.8 a 10.9 are hot yield stress values stated in standard DIN 267, section 13 or in EN 20 898, section 1 (Appendix).

d) For load Q may calculated stress value amount to 1.3 multiple of load G. 6.3.5 Permissible stress values for dynamically loaded construction elements: for rigid

struts, their connecting parts and clamps must be stress declared according to 6.3.1 - 6.3.4. In fatigue strength area for clamps is RmT/200000 in calculation of f replaced by 1% value of creep strength Rp1,0T/10000.

6.3.6 Permissible stress values in construction parts are determined by multiple of basic permissible stress according to element stress character and type of computational model according to Table 5.

Table 5. Permissible stress values in construction parts

No. Type of stress Category / Permissible stress

G Q BAR COMPUTATIONAL MODELS

1 Pure tension, compression or bending 1,00 * f 1,33 * f

2 Compression and compression in bending (stability prove) 0,90 * f 1,00 * f

3 Shear 0,5 * f 0,66 * f 4 Reduced stress (stress intensity) 1,00 * f 1,33 * f

WALL AND PLATE COMPUTATIONAL MODELS

5 Tension and compression 1,00 * f 1,20 * f 6 Bending 1,50 * f 1,80 * f

7 Compression and compression in bending (stability prove) 0,90 * f 1,00 * f

8 Shear 0,5 * f 0,66 * f 9 Reduced stress (stress intensity) 1,50 * f 1,8 * f

6.3.7 Permissible stress values for weld joints are determined by multiple of basic

permissible stress according to element stress character acc. to Table 6.


Table 6. Permissible stress values in welds

No. Weld type Stress type G Q

1 Butt Compress. / compress. in bending 0,70 * f 0,95 * f

2 Double fillet fully penetrated Compress. / compress. in bending 0,70 * f 0,95 * f

3 Double fillet fully penetrated Tension / stress intensity 0,70 * f 0,95 * f

4 Double fillet Single fillet fully penetrated Single fillet for a>6mm

Tension / compress. / bend. stress intensity 0,70 * f 0,95 * f

6 All Shear 0,5 * f 0,66 * f In case of NDT welds, permissible stress values No.1 – 6 stated in table are increased to 1.00 * f, respective 1.33 * f for load category Q.

6.3.8 Permissible stress of springs of constant and spring hangers Springs must be dimensioned to grant durability of circa 8500 hot and 1500 cold starts. Permissible torsion stress is determined according to DIN 2089, section 1 and EN 13906. It is acceptable to use permissible stress values for static stress. Furthermore, relaxation characteristics of material must be taken into consideration or such springs fabrication technology must be used to suppress influences of these characteristics.

6.3.9 Stability computation Stability check for ferritic steels is executed according to DIN 18 800, sections 2 to 4 or other computation methods.

6.4 Experimental realization of permissible load Experimental realization of component load capacity is executed acc. to standard EN 13480-3, annex J.


7 MATERIALS

a) Materials designed for use on pipe supports must have guaranteed mechanical characteristics and must comply with material bills acc. to table 7. Materials not mentioned hereafter are acceptable if their suitability is approved by purchaser.

b) Use of materials of types and quality classes according to ČSN, EN, DIN for pipe supports acc. to ASME specifications is possible only for parts with operational temperature up to 345°C. For higher temperatures, e lements must be fabricated from material according to MSS-SP 58 standard.

c) Only materials with sufficient ductility A>14%, hot mechanical characteristics and suitable technological properties are acceptable.

d) Materials designed for weld joints must have guaranteed weldability, with carbon content ≤ 0.22 %. Only killed steels may be used.

e) Material characteristics must be checked by manufacturer according to technical delivery requirements and must be documented by inspection certificates according to EN 10 204. Type of inspection certificate is stated in Table 7.

f) Maximum permissible temperatures of use for materials designed for pipe surrounding elements are stated in Table 8.

g) Materials designed for pipe support elements fabrication are stated in Table 7, along with technical delivery conditions.

h) Final material for springs must be checked according to quality class D(3) of standard EN 10221 for presence of surface defects, inhomogeneities and cracks.


Table 7. Materials for standard support elements

Materials Semi product Technical delivery conditions

Inspection certificate type

4.6, 5.6, 8.8, 8 Bolts Nuts EN 20 898-1 2.2* (nuts 2.1)

S235JR / J0 / J2 S275JR / J0 / J2 S355J0 / J2

Plates Formed rods

EN 10 025-2

2.2 / 3.1

P265GH 16 Mo3 13CrMo4-5 10CrMo910 1.4903

Plates EN 10 028-2

3.1 3.1 3.1 3.1 3.2

C35, C45 42CrMo4 24CrMo5 21CrMoV57

Round bars EN 10269 3.1

P235GH (11353.1) 16Mo3 13CrMo4-5 10CrMo910 1.4903

Tubes EN 10216-2 3.1

S355J2G3 C22 C35 P245GH 16Mo3

Forgings

EN 10250-2 EN 10222-2

3.1

Federstahl C 56Si7 51CrV4 46SiCrMo6

Wires Rods KR

DIN 17223 EN 10089

3.1

1.4301 1.4541 1.4571 1.4828

Plates

EN 10216-7 EN10095

3.1


Table 8. Max. permissible temperatures of use for materials of pipe surrounding elements

Material indication Construction part

Calculated temperature in °C

≤ 300* ≤ 450 ≤ 500 ≤ 530 ≤ 550 ≤ 580 ≤ 620

S235 JR * X

P235GH, P265GH X X

16Mo 3 X X X

16CrMo4-5 X X X X

10Cr Mo 9-10 X X X X X X

1.4903 X X X X X X X

1.4301 X X

1.4541 X X X

1.4828 X X X X X X X

5 / 5.6 a 8.8 * X

C35, 42CrMo4 X X

24CrMo5, 21CrMoV57 X X X X X

* is acceptable to use for temperatures up to 350°C with inspection certificate 3.1, bolts 2.2


8 INSPECTIONS AND TESTING

8.1. Fabrication tests For tests execution during serial production is responsible manufacturer of components. Tests are carried out according to test plan and type tests certificate.

8.2. Final inspection – standard catalog hangers an d supports After fabrication, following inspections are carried out in minimum presented scope, including first and last item of series / delivery:

a) Marking – 100%

b) Random tests of general performance and dimensions – 5%

c) Inspection of anti-corrosion protection – 5%

8.3. Standard spring and constant supports In inspection record must be enrolled:

- set load - blocked position - serial number - marking - type number - date and name of inspector

Inspection according to following points a) and b) is carried out in scope of 5% products, other tests, if not noted else, are executed for each support piece:

a) Random tests of general performance

b) Connection elements and threads

c) Constant hangers / supports – functionality test at set load in range of required travel, with record of load-travel diagram of at least 10 values for each travel direction, including minimum and maximum values. Set load and tolerated deviations in % must be recorded in diagram.

d) Function test for nominal travel of all spring hangers and supports. Of each series in scope of 2 %, but at least for 3 pieces, shall be executed record of load-travel diagrams.

e) Inspection of set load value and marking − set load − cold and hot load marks − cold position blocking − travel and load reserves − marking

f) Anti-corrosion protection


8.4. Pipe supports without catalog type 8.4.1 Basic data for design reexamination and approval by purchaser

a) List of technical parameters (minimum – maximum settable load, maximum permissible load, total travel, functional and dimensional tolerances, operational temperatures, temperatures of environment).

b) Assembly and detail drawings including bill of materials with declaration of material quality and with name of item number.

c) Strength calculations or records of load capacity

d) Weld plans WPS

e) Test plans for fabrication and test procedures at fabrication and for final and functional tests.

f) List of all basic data including revision list, which are necessary for pipe support identification

8.4.2 Fabrication tests

a) Tests must be carried out and results must be documented in compliance with approved basic data according to section 8.1, with compliance with certified quality system

b) Inspection of abiding of approved test plans, WPS, drawings (dimensions, weld execution), materials and anti-corrosion protection

c) Non-destructive tests

d) Validity check of fabrication and test plans approval

e) Check of welders and inspectors certificates EN 287, section 1 and EN 473

8.4.3 Final inspections For each delivery are following inspections executed:

a) 100 % marking check

b) Inspection of material marking and material records

c) Functionality of connection elements and threads

d) 5 % check of connection dimensions for each construction element

e) Inspection of anti-corrosion protection including coating thickness inspection


8.5. On-site tests For on-site tests execution must assembly organization elaborate plan of tests. On-site tests, if not settled else, are carried out by purchaser.

a) Accordance check of marking and material indication with manufacturer’s documentation and with delivery certificates (list of settable values)

b) Check of pipe support on compliance with approved basic data

c) Check of functional diagrams handover according to 8.3-c

d) Revision of completeness of material test documentation

e) Check of support integrity and anti-corrosion protection

f) Check of delivery bill completeness At presentation of type test falls off points a) to d), if they are respected to individual elements of delivered type.

8.5.1 Inspection of pipe support after installation

a) Compliance of installed pipe supports with drawings, eventually with specification

b) Fixation of pins and bolt joints

c) Check of sufficient thread engagement, e.g. on hanger rods and turnbuckles

d) Joint check for proper strength and shape connection

e) Site welds acc. to test plan

f) Sufficient clearance at guides

g) Clamps, supports and guides for safety seating

h) Bolt joints in alloyed materials for correct bolt materials

i) Installation position of flexible standard supports with respect to free movement possibility at thermal dilation and dynamic stress with respect to travel reserve

j) Check of support unblocking after pressure test

k) Cold and hot position of spring and constant supports

l) Position of spring and constant supports after following installation shutdown

m) Scale reading on constant and spring hangers


8.6. Repetitive tests

Repetitive tests, if not agreed else, are carried out by purchaser. Repetitive tests are executed only for pipe supports of class S2 and S3.

a) Performing of repetitive tests must be controlled by test plan, elaborated by pipe support manufacturer. Simultaneously it is necessary to declare scope and frequency of tests, execution acc. to checklists, as well as competencies and documentation method.

b) At creation of basic data for testing it is necessary to take into consideration the instructions for control and maintenance.

c) At repetitive tests are executed visual controls of: − pollution − condition of friction surfaces − visible deformations − free movement possibility − basic hot and cold position − position of pipe support installation


9 DOCUMENTATION

Documentation must contain list of pipe supports and assembly drawings. Pipe supports of class S1 can be documented by catalog sheet. Assembly drawing of pipe support, which is integral part of delivery, must contain besides specification list, installation manual and eventually other necessary informations for correct hanger assembly also following informations:

• name of project • name of pipe system • number of pipe support list • pipe support code marking KKS • hot and cold permissible load • hot movement values – horizontal and vertical • outer pipe diameter • insulation thickness • fluid temperature • spring rate • angle rod deviation • travel reserve of spring and constant supports

Manufacturing documentation:

• Welder authorizations, inspection of allocation WPS, WPQR • Raw material inspection, marks transfer, welding material identification • Visual inspection of welds • Dimensions check • Heat treatment • Function inspection of pipe hangers and supports • Check of preloading and blocking of pipe hangers / supports • Surface treatment and painting inspection • Final inspection – completeness and marking


10 RELATED STANDARDS

EN 13 480-3 Kovová průmyslová potrubí – Část 3: Konstrukce a výpočet

ČSN 130021-5.1 Potrubí – technická pravidla – Konstrukce – Část 5.1 - Navrhování

VGB – R 510 L Rohrhalterungen

FDBR Berechnung von Kraftwerksrohrleitungen

KTA 3205.3 Komponentstützkonstruktionen mit nichtintefralen Anschlüssen,

Teil 3: Serienmässige Standardhalterungen

ASME B31.1 Power Piping

ASME B31.3 Process piping

MSS SP58 Pipe hangers and supports - materials, design and manufacture,

standard practice

piping pipe supports technical requirements guideline

Documents