Definition of Heavy Wall in Pressure Vessels

Most likely what they are referring to is API RP 934-C: (or -A) "For this recommended practice, the heavy wall is defined as shell thickness 2 in. (50 mm) or greater but less or equal to 4 in. (100 mm)."

Also you may find API RP 934-A is what they are referencing.

You can also see the proposed API RP 934-B here:

http://committees.api.org/standards/cre/sccm/ballots/docs/Reballot934b-01-07.pdf

Furthermore, there is some explicit reference in ASME VIII-2 which would define "heavy wall" as R/t≤4; lastly there are also some references to heavy wall castings in VIII-1, -2, & -3 (but I don't think that applies in your question).

But in any case you should confirm with whomever is asking you to meet this criteria/whomever wrote the spec.

Thank you for the feed back.

Can you please inform the Clause under which it is defined in Sec VIII Div.2 ?

K.Periasamy

That criteria is in 5.2.1.3 in VIII-2 (2008a Edition)

Thank you very much.

K.Periasamy

According to ASME code, Section VIII, Division 1:

a. Thin wall equation for cylindrical shell thickness, UG-27:

t = P R / (SE – 0.6 P) , where t ≤ 0.5 R (or P ≤ 0.385 SE)

b. Heavy wall equation for cylindrical shell thickness, Appendix 1:

t = R (Z^1/2 – 1) , and Z = (SE+P)/(SE-P), where t > 0.5 R (or P > 0.385 SE)

Note. Please refer to ASME VIII-1 for a full details and to differentiate between equations for Circumferential Stress (Longitudinal Joints) & Longitudinal Stress (Circumferential Joints).

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what standard is being referred to by your client?