PetroStreet

Hi All,

In petrochemical industry, pressure vessels plates are used mostly of following grades:

A-285 grade A/B/C = Carbon Steel Pressure Vessel Plate for Low and Intermediate Tensile Strength
A-516 grade 60/70 = Carbon Steel Pressure Vessel Plate for Moderate and Low Temperature Service

My queries are:

1. Can we use A-285 grade C instead of A-516 garde 60 for manufacturing box-up enclosures & leak sealing clamps?
2. How we can testify / acceptance of both grades apart from MTC or PMI?

1. Whatever you choose for leak clamping, you must perform the complete calculation considering the allowable stress of a material at that particular temperature. See ASME Sec. II part D and check the allowable stresses of A-285 Gr. C and A-516 Gr. 60 against a specific temperature. Lets say you have to design a clamp for 600 deg F temperature, the allowable stress for A-516 Gr. 60 is 16.4 ksi and for A-285 Gr.C, 15.3 ksi which indicates that the thickness required for A-285 Gr. C plate would be greater than A-516 Gr. 60 plate.
2. No need to testify the materials if they conform to ASTM standard as declared by the supplier.

There is no problem in using A-285 Gr. C, just perform the right calculation of thickness as per allowable stress of A-285 Gr. C. Using this plate for clamping is a normal practice in Industries as A-516 Gr. 60 plate is not readily available in Industries' warehouses.

Arcpro / Ashfaq: Thank you for helping me out.

What if we have a CS plate with MTC not avilable, what would be the checks to verify whether the plate is of A-285 Gr. C or A-516 Gr. 60?

Regards - Qaisar

You must undertake the mechanical tests especially tensile which would be the first one. Go through the documentation of ASTM A285 and ASTM A516 to check the major differences and the tests to be made to verify them.

ok understood. thank you arcpro