Impact test exemption for PQR for 304 SS in low temp service
Impact test exemption for PQR for 304 SS in low temp service
(OP)
Dear all,
We have an existing 304 SS vessel with design temp of -150 F. Recently added a new 304 SS 6" feed nozzle.
However, our client indicated that the inlet temp for this new nozzle is -245F, so the local area on the shell will be colder and raised the question that our PQR does not show impact test.
We are looking into UHA-51, especially UHA-51(g) to see if we can exempt impact test on PQR. Can the very low stress ratio for the nozzle by UHA-51(g) be used to exempt the PQR from impact test for the nozzle to shell weld ?
We have an existing 304 SS vessel with design temp of -150 F. Recently added a new 304 SS 6" feed nozzle.
However, our client indicated that the inlet temp for this new nozzle is -245F, so the local area on the shell will be colder and raised the question that our PQR does not show impact test.
We are looking into UHA-51, especially UHA-51(g) to see if we can exempt impact test on PQR. Can the very low stress ratio for the nozzle by UHA-51(g) be used to exempt the PQR from impact test for the nozzle to shell weld ?





RE: Impact test exemption for PQR for 304 SS in low temp service
RE: Impact test exemption for PQR for 304 SS in low temp service
RE: Impact test exemption for PQR for 304 SS in low temp service
RE: Impact test exemption for PQR for 304 SS in low temp service
I would like to make sure I understand UHA-519(g) correctly: The primary membrane tensile stress from pressure and from UG-22 for the nozzle 'itself', is below 35% of the allowable tensile stress. From the wording in that clause, does it mean any welding to this nozzle (such as flange to pipe weld and pipe to shell weld), PQR can be exempt from impact test ?
RE: Impact test exemption for PQR for 304 SS in low temp service
RE: Impact test exemption for PQR for 304 SS in low temp service