Welders range of base materials qualified 4

[DeanIEng]

thread292-94927

I have read through the above referenced thread and a few others, to try and get an understanding of the range of base materials the welder can qualify for. I just can't get my head around what the ASME IX code is stating.
As I am quite a new person to the code, Could one of the experts on this forum try to explain it to a block head like me?
For example. If a welder joins a P1 material to another P1, then (with reference to QW 403-18 and QW 423-1) what range of base materials is the welder qualified for. If you could explain how you derive the answer in simple terms for a newbie like me I would be most grateful.

http://www.eng-tips.com/

Thank you,....

DeanIEng

 

[SectionIX]

Hi DeanIng,

Welcome to the forum. With respect to your questions, I offer the following.

Range of base metals qualified. This is found, as you have stated, in ASME Section IX QW 423.1.

Find the base metal used for qualification under "Base Metals for Welder Qualification" and follow across to "Qualified Production Base Metals" on the right.

For example, if you qualify on P1 material, you are qualified to weld P‐No. 1 through P‐No. 15F,P‐No. 34, or P‐No. 41 through P‐No. 49.

If you qualify on P‐No. 21 through P‐No. 26, you are qualified to weld P‐No. 21 through P‐No. 26.

Pretty much as easy as finding your qualification material on the left of the table and following across to the right to determine the [welder] qualified production material.

Regarding thickness and OD restriction as applied to welder qualification, Thickness of Weld Metal Qualified is found in Table QW-452.1(b; Groove‐Weld Diameter Limits Table QW-452.3, and again functions similarly to the above examples.


Base metal qualification for WPS is a bit more convoluted, but functions similarly as shown in QW 424.


Hope this helps.

 

[DeanIEng]

SectionIX (Petroleum),

Thank you for the concise explanation it is very much appreciated.
When I viewed table QW 423.1, I wasn't sure whether it meant that if you qualified with a P1 for example in the left hand column, that you then qualified only for the same P number in the right hand column, or whether it meant all of the P numbers in the adjacent right hand column.

I must admit I'm quite surprised that it is all of the adjacent P numbers.

Thank you once again,

DeanIEng

 

[weldstan]

Do not be indiscriminate in believing that the welder is qualified to weld all of the base metals shown. Remember that filler metal F No. is also an essential variable.

 

[Duwe6]

And take Sect IX with 'a grain of salt'. It is 'legal' per Sect IX to qualify a tig GTAW welder on a P-1 c/s coupon using ER70S-6 c/s wire F-6, and call that welder qualified to weld s/s 304/316 etc. P-8 using a ER308/316 etc. F-6 filler.* NOT TRUE in the 'real world'. Much harder to produce acceptable s/s tig welds, than acceptable c/s welds.

Just because one of your welders is certified as being able to make the weld does not necessarily mean that he/she has the ability to do it. Always listen to input from the welding foreman and the welding inspector, they are being paid to know the actual abilities of the welders.

*my guess is that this 'glitch' originated when s/s pipe was brutally expensive and only the better stick SMAW welders were allowed to tig tests. If you are good, you are good. But if you can just barely pass c/s pipe with c/s filler, you will not be able to pass s/s pipe using a s/s filler. I would love to see Sect IX recognize the change in 'degree of difficulty' between c/s and s/s tig welding.

 

[DeanIEng]

weldstan, Duwe6,

Thank you both for some very sound advice. I firmly agree that ASME IX needs to change with the times, and also be written in a more user friendly manner.

 

[DekDee]

DeanIEng,
Having used ASME IX for over 30 years (and also having a lot of experience with British / European / Australian and even Japanese codes / standards) I can assure you ASME IX is easily the most user friendly.

One issue I have always struggled with in ASME IX is if you qualify with GTAW on C/S you are qualified for S/S (within ranges noted above) but if you qualify with S/S you are limited to when you can weld C/S.
Deletion of Backing Gas is an essential variable so if you qualified on S/S with Backing Gas you are only qualified for C/S with Backing Gas.
Don't think too many employers are going to be keen to purge C/S,
Cheers,
DD

 

[sharmass]

Dear DeanIEng
Both base metal P no. and filler metal F no. are essential variables for welder qualification (apart from the other variables)
Section IX considers "SKILL" as important factor for welder qualification and the variables have been decided based on this consideration.

Look at it this way
If you qualify a welder on P no. 1 with E7018 (F no. 4) electrode, your welder can weld only F no. 4, 3, 2 and 1 (with backing)
Now you want to weld P4 material with E7018B2L (also F no. 4), you do not need another welder qualification as the skill requirements are not different for this combination.

Now with the same welder, you want to weld P8 to P8 (stainless steel) using F5 consumable. This is not permitted as the welder is not qualified for F5

Now consider GTAW process. If the welder is qualified on P1 to P1 without gas backing and F6 consumable, he can weld P8 to P8 as the GTAW consumable for stainless steel are also classified as F6 and the welder qualifying without gas backing can be used for with or without gas backing