The valve stem is mainly able to withstand pressure and can be well insulated, and is not easy to rot and rust. It has a double-sided sealing function, which is more wear-resistant and has a longer service life. So, there are several reasons for valve stem fracture or deformation:

The broken part of the valve stem is usually at the bottom of its upper and lower threads, as the area at this location is relatively small and prone to corresponding force concentration and exceeding the standard. Generally speaking, the moment when the valve stem is likely to break is when it is opened. Mainly because the hammer has not yet detached from the valve seat, and the rod of the surface or bottom line has broken. It is usually believed that the plunger is stuck. This is not all the reason, nor is it important.

When the middle chamber of the valve stem and valve body is closed, abnormal heating and pressure reduction occur, that is, after the valve is closed, the fluid pressure in the middle chamber closed between the upstream and downstream sealing surfaces is much higher than the upstream sealing surface. pressure