WPS and WPQT

[Syahar1975]

Dear Experts,

We have PQR coupon 10 mm thickness welded in vertical position. All required tests (RT, Tensile, Bend and Impact) are acceptable.

We made a WPS based in this PQR and due to impact requirement this WPS is only qualified for 10 mm to 20 mm plate thickness.

Then we have WPQT using this WPS but we use 14.5 mm thick plate for this WPQT. The test position is 3G, and multi layers. We use the same material for PQR and WPQT.

No PWHT requirement.

After radiography, the result of this WPQT is OK.

My understanding, since our WPS is qualified from 10 to 20 mm therefore this welder is qualified within 10 to 20 mm plate NOT 2 x 14.5 mm = 29 mm.

Any comments ?

 

[CWEng]

The WPS does not limit the qualified range you can write on the welder's WPQ paperwork, but it does limit what he can actually weld in your shop. The welder is qualified to 29mm, but he may not be able to utilize the whole range.

 

[Syahar1975]

CWEng,

Thanks for your comments.

So there is relation between WPS and WPQT ?

I read somewhere that if WPQT was done on 13 mm plate with multi layers so the welder is qualified for unlimited thickness. I am not sure where I can find this clause in ASME Sect. IX.

Syah

 

[DekDee]

Table QW-452.1(b)

 

[gtaw]

If the welder welds on base metal 1/2 inch thick (12.5 mm) and deposits at least 3 layers, he is qualified for unlimited thickness. However, the WPS has precedence over the welder qualification. If the WPS is limited to 3/8 inch, then that all the welder can weld in production unless the WPS is requalified for greater thickness.

Best regards - Al

 

[Syahar1975]

Dear all,

Thanks for your comments.

Now, I have another WPS qualified till 37 mm thickness. The material are the same.

So I can employ that welder to welded the vertical joint of 37 mm plate thickness with the above WPS right ?

Syah

 

[gtaw]

If you are working to ASME and you are not using GMAW-S, yes.

Best regards - Al