shielding gas each cyl consist 7cum gas wt 12 3kg press 150kg sq cm as p er drg no gas mixture of 82 argon 18 co2 as per en 439 m21 protection procedure quantity tolerance 5 age item category normal total po value variation permitted max 8 lacs shielding gas each cyl consist 7cum gas wt 12 3kg press 150kg sq cm as p er drg no gas mixture of 82 argon 18 co2 as per en 439 m21 protection procedure quantity tolerance 5 age item category normal total po value variation