Valve Dual Rating and Valve Material

MOC of cryogenic/low temp. valves are stainless steel, bronze, Special Alloy Steel. Overlays: Alloy 625, Tungsten Carbide, Chromium Carbide, Stellite. "conditions where we use SWP, NFPA, dual ratings of valves." It may be coincidental that a valve meets SWP & NEPA code. In a particular case SWP code may be equivalent to NEPA code. No valve can be made to two different code, unless they are equivalent.

Insufficient information. What fluid? What temperature? Which valve type? MOC of valve geatly depend on these three factors. Below -100 C you may call croyogenic, but material may not be the same for -100 C & -200 C. SS, bronze and brass are most commoly used materials for cryo service valves.