What is the difference between rising stem and non rising stem industrial gate valves?
One other difference is the fact that with a non rising stem valve, the screw threads that lift the gate are exposed to the fluid being controlled by the valve. This can cause problems if the fluid tends to foul the threads, so non rising stem valves are usually used on only clean liquids and gases. Rising stem valves have the threads external to the valve body and are not subject to fouling from the fluid the valve is controlling. Rising stem valves are usually made from cast or forged steel while non rising stem valves are more typically brass, bronze or cast iron. Non rising stem valves take up less space and rising stem valves require more space.
