Clarification on limits of Qualified WPS Per ASME B31.3

[petro84]

Hi Dear Friends
I ask my Question with an Example:
Consider that your Design Code for Piping System is ASME B31.3 and Also your material is in curve B;Design temperature is -29[0C]. So it is mandatory to take impact test for thickness greater than 12.7 mm. Now you know for PQRs with test coupon thickness it is mandatory to use qualification limit from ASME sec IX for thickness under 12.7mm and for greater thickness of test Coupon you should use T/2 to T +6mm Now here is my Question:
1) if our test Coupon thickness is 11.13mm then which one is the Qualified thickness:
a) 5 mm to 22.26mm
b) 5mm to 12.7mm
2) if your answer is 1-a then how you qualify part of thickness that requires Impact Test with a test Coupon that does not Require this test. and also if you use 1-a as correct choice then you can qualify P-N0 1 G-N0 1 to P-No 1 G-N0 1 for qualifying P-no 1 G-No 1 to P-NO 1 G-No 2.

if it is possible write your opinion and if you have any interpretation or Document Please share it. ?

thanks for your consideration

 

[DekDee]

Pedro,
Where does the requirement to only follow B31.3 requirements for greater than 12.7 mm come from ?

"Now you know for PQRs with test coupon thickness it is mandatory to use qualification limit from ASME sec IX for thickness under 12.7mm and for greater thickness of test Coupon you should use T/2 to T +6mm.

IMHO, If your coupon was 11.13 mm then you are qualified for 5.56 mm to 17.13 mm
Cheers,
DD

 

[petro84]

Dear Dekdee
if you take a look to table 323.2.2A then you will see that for thickness greater than 12.7 mm Design temperature without impact testing will be bigger than -29[0c] and as our design temperature is -29[0c] then Impact testing is required per Table 323.2.2 cell B-3. therefore testing qualification range for test Coupon with impact testing shall be done per cell A-5 of Table 323.3.1. If Impact testing is not required based on thickness of test Coupon therefore QW-451 of ASME sec IX shall be used for determining Qualified range.
Based on above consideration answer the question

thanks

 

[DekDee]

pedro,
Very surprised no-one else has joined in.

This is my understanding of B31.3 requirements
Table 323.2.2A states that for Curve B material - 6.4 mm to 12.7 mm the MDT without impact testing is 28.9 degrees C.
Obviously the WPS/PQR requirements fall under ASME IX for these thicknesses as the temperatures are above 29 degrees C.

Your MDT is 29 degrees C so it doesn't matter whether the WT is 6.4 mm, 12.7 mm or 11.13 mm - you must perform impact tests and the wall thicknesses qualified are governed by Table 323.3.1 (A-5).

My original answer still stands,
Regards,
DD

 

[DekDee]

pedro,
My apologies - I have misunderstood the requirements of Table 323.2.2A.
28.9 degrees C should have been rounded off to 29 degrees C.
However, I still stand by the thickness ranges noted.
If you impact test an 11.13 mm coupon your qualified thickness ranges are
5.5 mm to 22 mm for non impact tested applications
5.5 mm to 17 mm for impact tested applications
Regards,
DD

 

[petro84]

Dear Dekdee
you say 5.5 mm to 22 mm for non-impact tested applications ?!
but you should declare your opinion based on reality and as stated above for thickness greater than 12.7mm impact test is required.
Therefore whats your opinion now ?

Thanks for following and consideration

 

[DekDee]

pedro,
Once you qualify an ASME IX PQR it is applicable for B31.3, B31.1, B31.8, VIII etc so your qualified range shown on that WPS will be 5 mm to 22 mm as per QW 451.1.
If you impact test an 11.13 mm coupon then the range is limited (only if working to B31.3) to 5.5 mm to 17 mm.
If you want to use that WPS for 14mm thickness in production - no problem.
If you want to use that WPS for 18mm thickness in production - you have a problem.
Regards,
DD

 

[petro84]

Dear Dekdee
Did you mean 12.7 instead 14 mm ?

Regards