post heating of weld for 9 Cr material
post heating of weld for 9 Cr material
(OP)
I have to fabricate 20 identical tags in which a single spool piece of 4.2 meter long is having 16[1.5" sch160] nozzles welded on a 4" sch120 pipe [A335 P9] material.
My weld procedure calls for post heating at 300 deg C for min 1 Hr.
I will weld 4 nozzles at a time. what is the best method available for post heating of this nozzles? i do not want to use manual way of heating these by gas burner or cutting torch?
A quick response is highly appreciated.
My weld procedure calls for post heating at 300 deg C for min 1 Hr.
I will weld 4 nozzles at a time. what is the best method available for post heating of this nozzles? i do not want to use manual way of heating these by gas burner or cutting torch?
A quick response is highly appreciated.





RE: post heating of weld for 9 Cr material
RE: post heating of weld for 9 Cr material
For my own edification, would you only do one PWHT after all 16 nozzles were welded? The OP's comment about "doing 4 nozzles at a time" had me wondering if he thought he needed to do separate PWHT after each set of 4.
Patricia Lougheed
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RE: post heating of weld for 9 Cr material
RE: post heating of weld for 9 Cr material
sorry for late response.
Design code is B31.3 & yes, i will be doing PWHT also at 740 deg C for 3 Hrs. job thickness is 11.13 mm.
one of the consultant advised me that you will need to do PWHT of whole unit at a time within 72 hours from weld completion & if you delay the PWHT beyond 72 hrs. it will have adverse effect on the material. Is it tru?
Can you advise me how to go about it . will it be okay if i weld 4 branch at a time ,do post heating for those 4 branch joint at a time then move on to second lot of 4 branch joint, complete it & post heat it. And after completing all 4 sets go for complete PWHT of spool piece by electric resistance method.
but to complete welding of all 4 sets will take 4 days time, so i have fear that PWHT of whole unit will not take place in 72 hrs.
Awating your quick response
RE: post heating of weld for 9 Cr material