The standard of General Valve Flange Connection Iron Gate Valve requires that stem nuts be made of copper alloy or other materials with high strength and good wear resistance.
In the Standard of General Valve Flange and Butt Welded Steel Gate Valve, the material of stem nut should be made of copper alloy or nickel-containing cast iron with sufficient load-carrying capacity and minimum melting point higher than 954 C.
In the Standard of Steel Globe Valves and Lifting Check Valves for Flanged Connections of General Valves, the material of stem nuts is required to be made of copper alloy or nickel-containing cast iron with sufficient bearing capacity and minimum melting point higher than 954 C.
The standard of General Valve Diaphragm Valve requires that stem nuts be made of ductile iron or copper alloy.
In the general valve material standard, stem nuts are required to be made of cast aluminium bronze, cast aluminium brass and cast manganese brass.
