ASME B31.3-2018 nuts material for elevated temperatures

[ballvalve1337]

Hi,

ASME B31.3 Table A-2 shows nuts in stainless steel like 8MA, 8, 8A, 8CA, 8FA. They all are listed in A194 standard which is a high temperature standard. But A-2M only Shows values for min. temp. but not max temp.
Also in A-2M (metric) only 40°C (100°F) are permitted.
Why? I dont understand. I need an appropriate austenitic stainless steel nut for A193 B8M CL.1 bolts also applicaple for temperatures up to 850°F. B8M CL.1 is suitable for elevated temperatures according B31.3.

 

[ballvalve1337]

I received an answer vom ASME that there is an inconsistency in the Standard and it has been recorded as a request for Revision.