A333 Gr 6 Impact values at -80 C

[maxh]

Hi Guys,

I am looking at using A333 Gr6 for a low temp duty, but the equipment is made in Sch 160 pipe to PD5500 vessel code and the computed impact test temperature requirment is -77 Deg C, that standard test temperature for the material is somewhat lower.

Can anyone help me with some experience of doing impact testing at this low temperature as to whether or not you get sufficient impact values or would I be wasting my money on the tests by chasing a result that I cannot get.

Max

 

[metengr]

According to ASME SA-333, for Grade 6 material, the minimum impact test temperature is only -45 deg C, and must exhibit a minimum of 18J or 13 ft-lb. Going to -77 deg C will probably be a problem.

Why don't you switch to SA-333 Grade 3 material, which requires a minimum impact test temperature of -100 deg C?

 

[maxh]

Thank you for the suggestion I will look at Gr3.