Stem nut is composed of nut cap and nut bar ; nut dust cap sealing groove management settings , turn the nut inner peripheral surface of the rod to set the upper and lower ring groove , the outer circumferential surface of the rod nut ring grooves.
Stem nut has a certain strength and resistance to stress , because the valve stem nut is a process running in the intensity of the stem shaft directly to the stem nut . Stem nut and rotate the threaded stem , with the stem nut coefficient of friction is small. So as to avoid the phenomenon of generating killed or rust

Stem nut materials are copper alloys, steel and so on. Copper alloy stem nut is one of the main materials used . If Pg <1.6Mpa, stem nut made ​​of brass valves to be made ; If Pg16-6.4Mpa between the stem nut made ​​of materials can be used Wuxi bronze ; If the pressure is high , then you can use the yellow stem nut copper material .
The material can also stem nut steel . Sometimes it does not work in production and stem nut copper alloy materials . Because some products or environmental ammonia will corrode copper media , stem nut material can not use copper up . If on the basis of the electric valve stem nut with a melon -type clutch , which takes some of the heat treatment to get more surface hardness and maximum hardness. Choose to use steel stem nut , pay attention to the thread , steel stem nut prone to galling . But the stem nut on the valve is only suitable for low voltage , small caliber . Because stem nut material is less than the strength of such metal stem nut.