20 Valve Materials - Stem Nut Materials

The valve stem nut directly bears the axial force of the valve stem during the opening and closing process of Lined Valve, so it must have a certain strength.

At the same time, it is threaded with the valve stem, requiring a small friction coefficient, no rust and avoidance of biting.

1

Copper alloy

Copper alloy has a small friction coefficient and does not rust, and is one of the commonly used materials at present.

For low-pressure valves with Pg<1.6Mpa, ZHMn58-2-2 cast brass can be used.

For medium-pressure valves with Pg16-6.4Mpa, ZQAL9-4 Wuxi bronze can be used.

For high-pressure valves, ZHAL66-6-3-2 cast brass can be used.

Steel

When working conditions do not allow the use of copper alloys, professional carbon steels such as 35 and 40, and stainless acid-resistant steels such as 2Cr13, 1Cr18Ni9, and Cr17Ni2 can be selected.

Working conditions do not allow the following situations.

The stem nut with melon-shaped clutch used in electric valves needs to be heat treated to obtain high hardness or surface hardness.

The working medium is corrosive to copper. When choosing a steel stem nut, pay special attention to the thread biting phenomenon.