thermal stress relief

[danieleandrea]

dear all,
accordi to the 11th EDition of API 650 par.5.7.4 I need a clarification about the T.M.S. fot the materials under the groups I,II,III,IIIA.
For me the code states that:
if the thickness of the shell plate is grater than 25 mm or for any thickness if are present openings 12 nps or larger, T.M.S is mandatory.

 

[IFRs]

Section 5.7.4.2 of the code says that for plate material is I, II, III or IIIA AND the plate thickness is greater than 1 inch [25mm] AND the penetration is larger than 12 NPS then thermal stress relief is required. So for instance a 12" nozzle in a 1 1/2" plate does not get stress relieved.