What does "H" for H42W check valves mean?

Answer:

Valve type codeGate valve ---ZStop valve ---JThrottle valve ---LBall valve ---QButterfly valve ---DDiaphragm valve ---GPlug valve ---XCheck valve and valve ---HSafety valve ---ARelief valve ---YSteam trap ---SConnection form codeInternal thread ---1External thread ---2Flange ---4Welding ---6Yes, clip ---7Clamp ---8Jacket ---9Check valve and valve structure of codeLifting typeA.

H: Valve code, is the check valve code, 4: connection mode is flange connection; 2: valve form is vertical lift; W: sealed form, on behalf of the body of the sealing surface

through type ---1B. vertical ---2SwingA. single ---4B. multi flap ---5C. double flap ---6ButterflyA. double valve ---7B. single ---8Shuttle ----9H: Valve code, is the check valve code, 4: connection mode is flange connection; 2: valve form is vertical lift; W: sealed form, on behalf of the body of the sealing surface