Asme vs astm materials

[Redavocado]

I have an ASTM material used in a fitting at an elevated temperature. It is not listed by ASME so it doesn't have an ASME allowable stress atelevated temperature value. I may determine the allowable stress from the ASTM specs using ASME b31.3 2*Sy /3 or St/3 min. But how to get the Sy at a temperature above ambient when the ASTM Sy or St are not provided above ambient?

 

[metengr]

Redavocado
By your statement above, I would presume you had checked Appendix A in B31.3 for an allowable stress for this material, and it is not listed.

If this is correct, you can try to determine an allowable stress following the requirements in B31.3. Unfortunately, for elevated temperature properties you need to either find published values or conduct testing.

 

[Redavocado]

The questions still stands. How to derive allowable stresses at temperature from ASTM specifications when the material is not listed in ASME code? There are thousands of materials which ASME does not list currently (they are behind the times). ASTM does. ASTM lists temperature ranges in their specifications. How to use those temperature ranges to de-rate allowable stress values determined for unlisted materials per ASME B31.3, B31.3, SEction VIII, Div. 1?

 

[TVP]

Redavocado,

metengr just told you how to do this: either find reliable, published data on the material(s) in question, or perform your own testing. Also, ASTM does not include data on strength vs. temperature in their standards that can be used in a similar manner to the ASME codes.

 

[Redavocado]

Thanks.

 

[blacksmith37]

ASME only lists certain ASTM materials for code work . ASTM ID is "A" (eg. A106) ASME is "SA" (eg. SA106). ASME rarely changes the requirements of an ASTM spec to make it an ASME spec/material.

 

[GenB]

just get the CMTR and if the material has exact
chemical composition and test requirements y're okay, cert to ug-10 pg-10
the spec has to amtch that of the ASME.
genblr