Hi Everyone,
For our Cryo services, the MDMT is -165degC. Piping Specification used is SS 304/304L or SS 316/316L.
The Table 323.2.2 A-4 NOTES (6), only allows exemption of impact testing of base metal if the MDMT is -104degC or warmer
Extract below from B313.3 (ed2018) Notes6
(6) For austenitic stainless steels, impact testing is not required if the design minimum temperature is warmer than or equal to −104°C (−155°F), and the stress ratio as defined in para. 323.2.2(b) is 0.3 or less. See also para. 323.2.2(g).
So there is basically no option to be exempted from conducting Impact Test on the Base Metal since our MDMT is colder than the -104degC (ie -165degC)? Hence it is then mandatory to purchased material that are impact tested even if it is Stainless steel that can be used down to -254degC as per Table A-1. We do however enforce Impact Testing on the Weld Metal.
For our Cryo services, the MDMT is -165degC. Piping Specification used is SS 304/304L or SS 316/316L.
The Table 323.2.2 A-4 NOTES (6), only allows exemption of impact testing of base metal if the MDMT is -104degC or warmer
Extract below from B313.3 (ed2018) Notes6
(6) For austenitic stainless steels, impact testing is not required if the design minimum temperature is warmer than or equal to −104°C (−155°F), and the stress ratio as defined in para. 323.2.2(b) is 0.3 or less. See also para. 323.2.2(g).
So there is basically no option to be exempted from conducting Impact Test on the Base Metal since our MDMT is colder than the -104degC (ie -165degC)? Hence it is then mandatory to purchased material that are impact tested even if it is Stainless steel that can be used down to -254degC as per Table A-1. We do however enforce Impact Testing on the Weld Metal.
