New Technologies Used For Valve Stem

Valve stem is an important accessory for valves. It is used to transmit, connecting with actuator or handle. Valves stem is also used to drive valve bore to move or rotate, realizing valves on-off or regulation. 

 

During valves on-off, valve stem is not only moving part and stress part, but also sealing part. Meanwhile, valve stem suffers from shock or corrosion from media. It also rubs with packing. So, when chooses materials for stem, it must be ensured that valve stem should have enough strength, good impact toughness, bruise resistance and corrosion resistance. Valve stem is a vulnerable part. Nevertheless, machinability and heat treatment performance of materials should be focused when choosing materials. 

 

New technologies used for valve stem

1. Stem adopts home-made forging cold extrusion molding. The threads have high strength and accuracy. The accuracy is higher than that of threads on conventional valve stem. Conventional threads adopt spiral fly cutter. 

2. Concentricity of threads is in accordance with that of polished rod without traditional difficulties which have redoubled Chinese thread rolling process for a long time. Traditional chipless thread rolling is easy for bending, transformation and damaging thread rolling die.   

3. The polished rod adopts patented technology and the accuracy reaches to mirror plane effects. It is easy for on-off and have good sealing. Conventional polished rod has low accuracy and cost a lot of time.

4. T-slot on top of valve stem is manufactured by using forging forming process, having high efficiency and low cost. The whole technologies have reached to international advanced level.