substitute P355NL2 Plate whit A516 Gr70 plate in LPG tank

[ali119]

Hi everybody
I have a question about substitute P355 NL2 plate whit A516 Gr 70 plate in Liquid Petroleum Gas (LPG) tank that is designed by BS 7777 standard .
According to construction procedure we have to use P355 NL2 plate for first three meter of wall liner of LPG tank; but we used A516 Gr70 plate instead of. Now how can we demonstrate that use A516 Gr 70 plate is equal whit P 355 NL2 plate and there is no problem for this substitute?
Best regard

 

[metengr]

Since this is a nonconformance you need to engage the owner of the LPG tank to approve this material substitution. How do you go about it? I would perform a review of the chemical composition differences, mechanical property differences and impact test or notch toughness differences. You need to lay this information out on a spreadsheet and compare.

 

[stanweld]

I can only add that SA-516-70 has been used in many such LPG tanks designed and constructed to ASME VIII, Div.1.

 

[SnTMan]

ali119, does BS 7777 standard permit A-516 material?

Regards,

Mike