Understanding Essential Variables-Need Help

Date 05-30-2009 09:12

Hi Friends
Appreciate if someone helps me defining as much as possible

AWS D1.1-2008-Essential Variable changes for CVN Testing Application requiring WPS requalification.
Under Position Variables:-"A change in position to vertical up.A 3G vertical up test qualifies for all possitions and vertical down"
But then why require requalification for SMAW/GMAW/FCAW/GTAW? I 'm really lost.
Only in 3G / 3F either verical up / vertical down is applicable.
Is it mean to confrom 3G WPS/PQR is enough to automatically qualify for 1G, 2G, 4G ?

Pls guide me
Thanks

By jarcher (**)

Date 05-30-2009 21:22

This is pretty much the same position that ASME IX takes in CVN testing. A vertical up weld is assumed to have the slowest travel speed, thus producing the highest heat input. Since notch toughness is related to heat input, the idea is that if you get acceptable results in 3G, you will get acceptable results in other positions. Note that this does not set aside the need to qualify other positions by PQR, at best it simply means you only have to take charpies from the 3G plate.

By rickc

Date 06-03-2009 16:06

What jarcher said!
The Table 4.6 requirements are in addition to those listed in Table 4.5. So, the WPS is still limited by Table 4.5 #27, "A change in position not qualified by Table 4.1."

By Nalla

Date 06-04-2009 22:21

Hi, Friends
Table 4.1 - Test Position - 3G - Qualified Range - 3G Position ONLY
Table 4.5 # 27 - same restriction as shown in Table 4.1
So what is the coorelation between Table 4.1+4.5#27 & Table 4.6#6- Pls explain.
Thanks