ASME B31.3 Fluid Categories 1

[IntegrityGuy]

ASME 31.3 defines Category D and Category M fluid service. What does the "D" and "M" stand for?

 

[BSAS-GWB]

Check out paragraph 300.2 Definitions, for details of fluid service.

I've had a cursory look in my process piping books and could not find any significance of the specific letters D and M. Perhaps somebody else is aware of the history?

 

[LittleInch]

Perhaps roman numbering - D is 500, M is 1000?

Perhaps M stands for "more" and D for "domestic"?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[bimr]

Perhaps the categories started out as Appendix D and M.

 

[moltenmetal]

No idea about the origins of Categories D, M or K.