B31.8-BVPC postweld heat treat on thick blinds with weld joint less than 1.25" effective throat

[alsy]

Subject: Is stress relieving (PWHT)on a B16.47 6.75" thick A-105 blind flange required when attaching a nozzle that has an effective throat less than 1.25"? This is a non lethal service- UW-2 does not apply. Construction code is B31.8 Reference section 825.2

Hello all. I am looking for some insight into when PWHT would be required on a thick blind flange. BVPC Table UCS-56 (2)(b) says "welded joints over 1.25".......B31.8 825.2 simply states "nominal wall thickness over 1.25"..... Other codes appearing to follow BPVC "ME.S.008 CSA "effective throat of over 1.25 PWHT is required"

My interpretation would be that as long as the welded joint (in this case a 2" XXH nozzle (wall thickness 0.436") to a 6.75" thick 600# 42" blind flange), has the effective throat of the weld less than 1.25", then PWHT is not required per UCS-56. Another engineer thought PWHT was automatically required because thickness of flange exceeded 1.25"

Any insight is appreciated.

Thanks!

"Success is not final, failure is not fatal: It is the courage to continue that counts."
Winston S. Churchill

 

[weldstan]

PWHT is not required per 825.3 and the definition of nominal wall thickness in 804.5.