What SA-105M stand for?

[maulidinbastian]

I buy a new valve from supplier which have different specification from I requested. Please help me on differ between SA105-HF and SA105M HF? I use this material on bonnet.

For Body, i request to use S25C.STPG370 and the vendor supplied SCPH2, which is the best one? The operating conditions are saturated steam, P: 117kg/cm2.G and T:324.1degC

Thank you..

 

[stanweld]

M is for metric.