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Re: [MW:29831] Regarding PWHT as per B31.3 and B31.1

Greetings,

I hope youre into power generations, where you touch, boilers, power and process...

Find my reply below in green, rest acceptable..

( As per my knowledge  1) PWHT temperature for ASME P number 04 material is different from ASME B31.3 (process) : range 704-746°C to ASME B31.1 (Power) : range 650-700°C.)

Reply:  I have 2016, 31.3 vs 12, 31.1, which does not has this major difference for P no 4,  to be precise (.3) comes with 650 to 705, where as (.1) with 650 to 700, which is acceptable. there are other P nos which has more than 5 Deg variations, which is not your case.

Below I have given some WPS parameters for PWHT, please clarify me whether the parameters are correct or Not. 

According to B31.3 -

Material : ASTM A 335 P11 to ASTM A 335 P11 - ( PNo-4; G.No-1 to PNo-4; G.No-1 )
Process : GTAW
Test coupon Thickness :  19.05 mm

Reply: why do you go with full GTAW for 19.05??

PWHT- Temp range - 690°C- 705°C

Reply: 690 is ok

Heating range : 200°C/hr
Cooling range : 200°C/hr
Interpass temp : 315°C  
Post Heating : 300°C -350°C ; holding thickness 10mm to 20mm -30 min / 20mm to 30mm - 90min.

Reply: i made something like this and approved, A minimum of 25% of the groove weld is filled, the weldment is sufficiently supported with Post heating gradually increasing as per the WPS requirement 400 deg C  at 2 hours after the welding completion, the bottom line is started after 25% with gradual fullfilled post heating after weld completion for continous 2 hours at 400 deg C.

And regarding Backing -  PQR is qualified with Argon, can we use Nitrogen in WPS.

Reply: read QW-408.2.


Yours
MOHAMED MUNEEB MAHABOOB
+91-786-700-444-6      TRZ - INDIA

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