WPS for review 1

[engr2GW]

Hello everyone, I have a WPS for review to get your opinions please.

1. Base metals: ASTM A-510-06 GRADE 4130 to A 106 GRADE B
2. Purpose: For welding the last API flange (4130) to flow line pipe (A106), that is where the code break goes from API 6A to ASME B31.3
3. filler metals: GTAW root and E7018 fill and cap
4. Pre-heat: 300 F minimum
5. PWHT: 1250+-25F 1hr/inch of thickness, but not less than 1.5hr
6. Base metal thickness: 0.600"
7. Thickness range qualified: 0.1875" - 1.200"
8. Charpy Impact testing: None (MDT is above -20F)
9. Position and progression: All and Upwards
10. Additional question: I understand that 4130 being an unassigned metal when qualified cannot be substituted for say a 4140, etc. But my question is, the PQR welds 4130 to A106B, this qualifies 4130 to any P1 of thesame class as A106B right? like A106A, C, X-42, X-46, X-52...

Thanks you very much for your help!

 

[stanweld]

I would increase the preheat to 400 F. Yes to question 10.

 

[engr2GW]

Thanks Stanweld.
Last Question, the absence of Charpy impact testing is not a problem for the application, service, and materials right?

THANKS A LOT

 

[stanweld]

Yes, provided impact testing is not required. Under B31.3, the Owner's Engineer is responsible for determining MDMT; I cannot.

 

[engr2GW]

And this is equal to the minimum possible anticipated temperature (process, ambient, etc) that the facility will be subjected to right?
meaning if know it will not go below -20F then the WPS is good right despite the presence of a 4130 in the weld?

If the above is yes, will that be the same for a 4130 to 4130 weld with the variables similar to the one posted above?

 

[stanweld]

The minimum ambient temperature may or may not apply to the MDMT. The question of thickness of your materials and ASME B31.3 Fig. 323.2.2A and Table 323.2.2A was addressed in one of your previous questions.

 

[Duwe6]

PWHT hold time may be a bit high -- 1 hour/inch thickness, no less than 1-hour has worked well. But nothing wrong with spec'ing extra.

 

[engr2GW]

Thanks Duwe6, I actually had that changed before your email came in, your post confirmed my thought. Thanks again.

 

[engr2GW]

4130 is unlisted and A106B requires Charpy above 0.5", that mean I have to do Charpy, I can simply take the remaining coupon, impact test it, and update the PQR/WPS if it passes right?

As much as possible, do it right the first time...

 

[Duwe6]

Assuming that you recorded maximum interpass temperature, and heat input [amps and volts vs. travel speed] then yos, you may just submit the remaining coupon.

Without all this data, you will need to make another PQR coupon, but only run Charpies on it. You've already proved out the WPS/PQR with the earlier destructive testing.