Valve stem deformation

Valve stem deformation:
The valve stem mainly has the comparison to be able to press, can very good carry on the heat preservation, also is not very easy to corrupt and the corrosion, it has both the seal function, the comparison is durable, and its service life is long. Then the valve stem can be broken or deformed there are so few points:
1 area
The valve stem is usually broken at the bottom of its upper and lower threads, because the area is relatively small, easy to appear the strength of the corresponding concentration and beyond the standard.
2 in the open fracture
Usually the valve stem is the most likely to break the accident is the moment when the open. The main reason is that the gate has not left the valve seat, the valve stem in the root of the root fracture, under normal circumstances will be considered to be stuck, this is not the whole reason, nor is it the most important.
3 body
The body cavity is closed after the abnormal temperature rise and pressure, that is, after the valve is closed, the sealing surface between the upper and lower sides of the sealing surface of the fluid pressure to the upper reaches of the upper reaches of the situation. The reasons are as follows:
(1) expansion
(2) the fluid pressure in the chamber is much higher than that of the upstream pressure. The reasons are as follows:
(1) expansion
(2) closed