using material sa-537 cl1 or cl2

[sadminto6]

Hi every body
Can every body advice me that, what is different between material A537 CL 1 and A537 CL 2?
The above materials is used for LPG service (in spherical tank ) with the design condition is:
Temp. Operation/Design: 28/-10deg.C
Wall Thickness : 57 mm

Hope to see your advice soon

 

[metengr]

The main difference is in ultimate tensile and yield strength values. The Class 2 has higher values.

 

[pradipgoswami]

Both are C-Mn(1.4% max) steels. Class 1 is Normalized-70 Ksi UTS category, while Cl2 is Q&T grade with nominal UTS-80 Ksi. For the above design temperature both grades would be appropriate, with reasonably good impact values @-(-)10 DegC.

Choosing Cl2 grade would save on materials(lower design thickness due to higher Y.S and UTS). However welding consumables with 80 Ksi nominal UTS would be required to match the base metal strength,after PWHT.

PWHT would be must for 57 mm wall thickness.

Thanks.

Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299
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