As an integral part of the valve fittings, in the practical application, the stem part mainly plays the role of bearing pressure, and at the same time, it can carry out good heat preservation, and it is not easy to be corroded and rusted, and it has the sealing function of both sides. It is more resistant to wear and it has a long service life.
If the use is improper or there are other abnormal problems, the valve castings of the valve fitting may also be broken or deformed. The stem usually breaks at the bottom of its upper and lower threads, because the area of that place is relatively small, and it is prone to corresponding concentration of forces and beyond the standard.
There is also a case where a break occurs at the time of opening. This is mainly because the shutter has not left the valve seat, and the valve fitting stem is broken at the root of the upper or lower thread. In general, it is considered that the gate is stuck. Living. When the middle cavity of the valve body is closed, abnormal temperature rise and pressure drop occur, that is, after the valve is closed, the pressure of the middle cavity fluid enclosed between the sealing faces on the upstream and downstream sides is much higher than the upstream pressure. http://www.dmgcastings.com/