Positions

Date 01-19-2012 12:39

Hi Firefly

The welding direction / progression is a suplementary essential variable, so is only applicable for impact test applications.

In the case of impact test applications, you are correct that a plate welded uphill in the 3G test position will qualify all other positions. I am not sure why you have included the 73mm OD limitation, because for procedure qualification, diameter is not an essential or suplementary essential variable.

Regards
Niekie

By Firefly (*)

Date 01-20-2012 10:09

Noted thankyou Niekie

By 803056

Date 01-22-2012 02:02

When qualifying a WPS, I believe the position of the test plate is a supplimentary variable that kicks in when notch toughness is a concern. Progression when qualifying a WPS is a nonessential variable for processes such as SMAW, GMAW, and FCAW, but not SAW (ever see anyone welding in the vertical position with SAW, didn't think so).

Best regards - Al

By Firefly (*)

Date 01-23-2012 13:40

Noted thankyou 803056. Am I correct to say that it is only ASME IX that incorporates supplementary essential variables i.e. welding codes such as AWS D1.1 and others do not incorporate such supplementary essential variables?

By 803056

Date 01-23-2012 14:40

They do, but they may not refer to the additional variables as "Supplementary". In the case of AWS D1.1 (later editions) consider table 4.6 where all the additional variables are listed for qualifying a WPS when notch toughness is a concern. The title of the table is "PQR Supplementary Essential Variable Changes of CVN Testing Applications Requiring WPS Requalification for SMAW, SAW, GMAW, FCAW, and GTAW". Talk about a mouthful of words!

Best regards - Al

By Firefly (*)

Date 01-24-2012 12:47

Noted thankyou Al. Much appreciated.

By Firefly (*)

Date 01-27-2012 10:11

Al, Niekie,

I had a look in AWS D1.1 (2010 version). For WPS qualification when using plate (groove welds). Table 4.1 states that qualification in 3G qualifies for V (vertical) welding only. However table 4.6 states "A 3G vertical up test qualifies for all positions and vertical down". It looks like the code is contradicting. Could you please advise your thoughts on this one? Thanks

By ozniek

Date 01-28-2012 05:29

Hi Firefly

On the surface, the two tables do look somewhat contradictory, but I think the way of reading it is as follows:

If you need impact properties (In other words your test piece needs to be subjected to impact testing.) then you only need to perform that testing on a test piece welded in the vertical up position / progression. You still need to comply with the Table 4.5 requirements, which point you to Table 4.1. So if you want to perform production welding in the F; H; V and OH positions for welds requiring impact properties, and you are qualifying on plate coupons, then you need to weld a coupon in each of the 2G; 3G & 4G positions, but only need to do the impact testing on the 3G coupon. All other tests need to be done on all the coupons.

Hope this makes sense.

Regards
Niekie

By Firefly (*)

Date 01-29-2012 10:11

Noted thankyou Niekie. Makes perfect sense.

By 803056

Date 01-29-2012 11:52 Edited 01-29-2012 12:15

This post and the responses with regards to D1.1 would be appropriate in the section for D1.1 since many welders working with D1.1 may never or rarely visit the section dealing with ASME issues.

I agree with Niekie that a test plate welded in the vertical position, using uphill progression qualifies the WPS for all positions with regards to notch toughness (CVN). However, if production does not require welding in all positions there is no need to weld a test plate in the 3G position. Only those positions used for production welding need to be tested with CVN. In other words, if production welding is only performed in the flat and horizontal positions, test plates for those two positions need to be welded and tested with CVN testing included. However, if the fabricator has to weld in the vertical position in production or if the fabricator finds it more expedient, he can weld plates in each of the positions required for production and perform the standard test regiment plus CVN tests on the one plate welded in the vertical position. The remaining plates, welded in the other positions required for porduction, would be subjected to VT, volumetric NDT, and guided bend tests as well as reduced section tensile tests (the standard test regiment).

Best regards - Al