Prequalified of WPS's

By Gweld Date 02-08-2008 01:17

I am more familar with ASME section IX but I am being asked to write some procedures using D1.1. It appears that all of my WPS's fall under prequalified. I have the following questions.

1. Do I have to write a new WPS for every prequalified joint? Or can I list all of the joint details on 1 WPS?

2. The sample in 2006 version for prequalified WPS's shows the thickness of base metal to be 1 inch but if you look at the joint listed it is for unlimited. Why is this?

3. How are fillet joint designations decribed in the joint details of WPS?

I am very green at this so any help would be appreciated.

By eekpod

Date 02-08-2008 11:30

If you hit the search button on the top of the screen and type in WPS, and such you will get alot of hits on this topic. This is something that comes up every month or so and sometimes it gets repepitive to keep answering the same question over and over. Good Luck, Chris

By jwright650 (*****)

Date 02-08-2008 13:20 Edited 02-08-2008 13:47

For your question number one look at Table 4.5 item 31. Any change in groove type constitutes writing another WPS.

Question #2: If you test on any thickness below one inch the welder/WPS is only qualified for 1/8" up to 2 times the thickness of the test material, but if you test with material 1" and over it is qualified for 1/8" to unlimited thicknesses.
EDIT: see table 4.2 for WPS qualification ranges of thickness and Table 4.11 for the welder qualification range of thicknesses.

I'll take a stab at the other question in a little while...I have to run UT some joints in the shop right now.....

By GRoberts (***)

Date 02-08-2008 20:36

John,
I would have to respectfully disagree with having to write a new WPS for every joint. You need to write a new prequalifed WPS for any change in essential variables outside table 4.5, per 3.6. However if you look at table 4.5 #31, a change in groove type is not an essential variable if prequalified joint details are used. Since by definition, prequalified joint details must be used for prequalified WPSs, then the WPS can specify multiple joints conforming too prequalified details.

That's my story and I'm sticking to it. Mostly because if I had to write a different WPS for each joint (D1.5 WPSs included), we would have about 10,000 WPSs instead of only 500. In my estimation, having more WPSs than necessary only confuses the situation on the shop floor and kills lots of trees.

By jwright650 (*****)

Date 02-08-2008 22:11

I have one written for each process we use and for each joint detail in Figures 3.4 that apply to the work that we do.

By GRoberts (***)

Date 02-09-2008 04:48

It can definately be done that way, and for some shops it probably works quite well, but for others it would be impractical. I don't think it is a code requirement though.

By jwright650 (*****)

Date 02-08-2008 13:45

For fillet weld WPS you need to follow paragraph 4.11.

Something that is in the Annex that helps when writing WPSs is Annex Q. This gives you things to check off or think about so that you don't leave off important info on your WPS. Also refer back to Table 4.5 to make sure your production welds will not be varying any of the essential variables that might require a retest or a new WPS to be written.