B31.12 - Mf Factor for Stainless Steel Piping

[RobsVette]

Good Afternoon,

We are working with some piping that will be containing Hydrogen at 2400 psi. The piping will be 316 stainless steel. We dont see any clear direction in the code text as to what value to use for Mf for stainless steel. Table IX-5C contains values for low and intermediate alloy steel performance factors, but there is no such table for stainless steel, which leads me to believe a value of 1.0 is appropriate.

I was hoping someone who has more experience with hydrogen piping could point me in the right direction.

Thanks
Rob