ARTICLE KD-10SPECIAL DESIGN REQUIREMENTS FOR

INTERLOCKING STRIP-WOUND VESSELS

KD-1000 SCOPE

(a) The requirements of this Article apply specificallyto pressure vessels consisting of an inner cylindricalshell and a surrounding winding, where the windingcarries a part of the end load. The vessel is fabricatedby helically winding a profiled, interlocking strip overthe total length of the vessel. The special requirementsare in addition to the general requirements given inArticles KD-1 through KD-6.

(b) To meet the requirements of this Division, thewinding of the profiled strips shall be accomplished insuch a way that the tightness of the winding is ensuredat all operating and upset conditions.

(c) During fabrication, a profiled strip is helicallywound continuously over the total length of the vessel.The strip material may be heat treated during thewinding process or only heated to achieve prestress.Alternatively, the prestress may be achieved by windingunder tension.

(d) For the calculation of static strength, the equationin KD-251.2 shall be used.

KD-1010 NOMENCLATURE

Ap outside diameter of the flangeCp pitch circle of the bolts

DIp inside diameter of the vesselDkp outside diameter of the inner cylinderDpp sum of the diameters of the holes in the blind endDsp outside diameter of the threadLp large radius of the torispherical shapehp length of the shrink ring for strip-wound flange

hRp length of the shrink ring for blind end or invertedflange

,p length of the threadrp small radius of the torispherical shape

sRp thickness of the shrink ring for blind end orinverted flange

91

tB1p thickness of the blind endtB2p thickness of the blind end having an inside tori-

spherical shapetB3p thickness of the blind end, including the length

of a tapered or rounded transitiontsp total thickness of the strip-wound vessel wall

NOTE: Any consistent system of units may be used.

KD-1020 REQUIREMENTS FOR FATIGUEEVALUATION

The fatigue evaluation shall be done in accordancewith Article KD-3 assuming the worst mean stresscondition in the strip during the fatigue cycle, i.e.,snm p Sy − Salt .

A mean stress correction factor shall be applied tothe inner shell in accordance with KD-310 only if bothof the following conditions are met:

(a) the residual bore stress which was determinedduring fabrication is corrected for the effects of hy-drotest;

(b) the inner shell is not of welded construction.

KD-1030 FURTHER DESIGNREQUIREMENTS

KD-1031 Thickness of Inner Cylinder

The thickness of the inner cylinder shall not beless than:

(a) 10% of the total wall thickness if the bolts forthe flat heads are screwed into the strip material onboth ends of the vessel;

(b) 20% of the total wall thickness in all other cases.

COPYRIGHT American Society of Mechanical EngineersLicensed by Information Handling ServicesCOPYRIGHT American Society of Mechanical EngineersLicensed by Information Handling Services

KD-1032 2001 SECTION VIII — DIVISION 3 KD-1035

FIG. KD-1032 INTERLOCKING STRIP-WOUND VESSEL DETAILS

KD-1032 Dimensions of Strip-Wound Flanges

The minimum dimensions of the flange depend ontotal wall thickness and outside diameter of the boltsDs.

The following requirements are valid for inside diam-eters of 18 in. to 72 in. (457 mm to 1 800 mm) (seeFig. KD-1032):

, p 1.8Ds

h p 1.6,

C p DI + Ds + 2.2ts + 8 in.

A1 p DI + 2Ds + 2.2ts + 8 in.

A2 p C + Ds + 1.5ts

A p larger of A1 or A2

KD-1033 Thickness of Blind Ends

The thickness of blind ends [Fig. KD-1033, sketch(a)] shall not be less than

tB1 p DI ! P(1.5Dk − DI)2(Dk − Dp) (Sy /1.5)

92

For blind ends having an inside torispherical shapewith r ≥ 0.15DI and L ≤ 0.8DI [Fig. KD-1033, sketch(b)], the thickness shall not be less than

tB2 p tB1 − 0.08DI

KD-1034 Transmission of Longitudinal ForcesFrom Blind End to CylindricalPortion of Vessel

In order to get a satisfactory transmission of longitudi-nal forces from the blind ends or inverted flanges tothe strip-wound wall section, the lengthtB3 in Fig. KD-1033 shall not be less than:

tB3 p 2.7(DI + ts)ts

Dk

KD-1035 Heating and Cooling Coils

Strip-wound vessels may be fitted with heating orcooling coils. However, provisions shall be made toprevent leakage between the strips. An acceptablemethod is shown in Fig. KD-1035. In this design, theprofiled strip of the heating coil is not taken intoaccount when calculating the vessel wall thickness.

If external heating devices are used, the temperaturegradient in the wall shall be calculated. The temperaturedifference shall be limited such that a positive interfacepressure will be maintained at the interface betweenall strips.

COPYRIGHT American Society of Mechanical EngineersLicensed by Information Handling ServicesCOPYRIGHT American Society of Mechanical EngineersLicensed by Information Handling Services

KD-1036 PART KD — DESIGN REQUIREMENTS KD-1040

FIG. KD-1033 INTERLOCKING STRIP-WOUND VESSEL DETAILS

FIG. KD-1035 HEATING/COOLING JACKETS FOR INTERLOCKING STRIP-WOUND VESSELS

KD-1036 Shrink Rings for Fixing the Ends ofWinding Strips

The ends of the winding strips shall be fixed eitherby welding or by shrink rings. The thickness of theshrink ring shall not be less than:

sR p 0.03(DI + 2ts)

or at least 1.5 in. The length of the shrink rings shallbe not less than:

93

hR p 0.25(DI + 2ts)

KD-1040 OPENINGS AND THEIRREINFORCEMENT

Openings are not permitted in the shell of helicalwound interlocking or noninterlocking strip con-struction.

COPYRIGHT American Society of Mechanical EngineersLicensed by Information Handling ServicesCOPYRIGHT American Society of Mechanical EngineersLicensed by Information Handling Services