SS 347 or SS 316L FOR VALVE BODY

[quiinces]

Can we use either of them at identical service conditions for Valve body material..such as 90 deg C/ 2000 Psig crude oil service.
which one is better of the two.

As per our spec SS347 is mentioned but vendor is offering SS316L

 

[Danlap]

Your pipe spec is SS347 for some reason. Maybe the offset maximum design temperature is higher or in the past / design phase, possibility of inter-granular corrosion was found/estimated. Or else
That you need to understand the philosophy first.
Once you accept the SS316L, the next replacement more likely to be SS316L also (in the next 3-5 years) and deviates further from the design selection.

Refer to ASME 16.34 table 2-2.2, both material belong to different regime. Even though the value is almost similar, this is not apple-to-apple. More to apple to peach.
There is also a major risk that shall PWHT required for the dissimilar metal weld will soften the SS347 (your existing Pipe spec I presume) material to a yield and tensile strength below code minimum requirements.
If the risk has been assessed. The operating temperature is below its Maximum design temperature and controlled. Minimal inter-granular corrosion possibility, less critical parts of your plants, etc. then the decision is yours.

Regards,
MR

All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected