P1 to P43 Dissimilar Joint PWHT Requirements

[Dhamodaran]

Dear All,

Code                   :  ASME Sec VIII Div.1

Shell Material       : SA 516 Gr.60

Nozzle Material    :  UNS N06625

UCS 56 (c) When pressure parts of two different P‐Number groups are joined by welding, the postweld heat treatment shall be that specified in either of Tables UCS-56-1 through UCS-56-11 or Tables UHA-32-1 through UHA-32-6, with applicable notes, for the material requiring the higher postweld temperature. 

My question is regarding the PWHT requirements for above vessels,

1.Does the shell to nozzle weld  edges to be buttered by Er NiCrMo-3 before PWHT and groove welding by Er NiCrMo-3  after PWHT? 

or

2.Or a PQR of dissimilar joint P1 to P43 with PWHT (of P1 requirements) can be used directly?

UNF 56 : Does not address such dissimilar joint

UNF-56 POSTWELD HEAT TREATMENT

(a) Postweld heat treatment of nonferrous materials is not normally necessary nor desirable.

Kindly share your experience/recommendations.

Thanks.

[S.Mohammed]

My question is regarding the PWHT requirements for above vessels,

1.Does the shell to nozzle weld edges to be buttered by Er NiCrMo-3 before PWHT and groove welding by Er NiCrMo-3 after PWHT?

YES.

or
2.Or a PQR of dissimilar joint P1 to P43 with PWHT (of P1 requirements) can be used directly?

P43PWHT NOT RECCOMENDED.HENCE GO WITH OPTION ABOVE.

[Pravin Nimbalkar]

If you have PQR of ENicrMo3 weld built up on P1 material to P43, then it is the best solution for this joint.

If with PWHT with impact test vessel, then you should follow same procedure for this production joint.