When the medium passes through the valve, the pressure in the middle cavity of the valve body may push the stem out (or when repairtng the valve. if there is pressure in the middle cavity, the stem and the medium will easily fly out when the valve is dismantleq causing accidental injury to personnel).

 

In order to prevent this from happening, a boss structure is provided at the lower part of the valve stem. In this way, even if the packing and thrust bearing are burned or damaged by other reasons during a fire, the medium pressure in the valve body will make the valve stem boss and the sealing surface of the valve body come into close contact so as to prevent a large amount of medium from being damaged. The purpose of leakage at the packing site.

When operating the valve, due to the friction between the ball and the valve seat of non-metallic materials such as polytetrafluoroethylene, electrostatic charges will be generated and accumulated on the ball.

In order to prevent the generation of static sparks, an anti-static device is specially installed on the valve, and the charge accumulated on the sphere is led out through the electrostatic passage between the sphere and the valve stem, and between the valve stem and the valve body.

In the event of a fire, non-metallic (non-fireproof materials) such as packing andvalve seats will be burnt out A large amount of leaked media may further promote the spread and expansion of the fire.

At this time, the valve's fireproof structure can prevent a large amount of media from leaking. As shown in the following figure, once the valve seat is burned, the ball will directly contact the metal surface on the valve body, thereby preventing a large amount of medium from leaking from the burned valve seat.

The connecting part of the valve body and the left body is sealed by gaskets. In order to prevent the leakage of the seal caused by factors such as fire, high temperature or vibration, the valve body is specially designed to contact the metal-metal of the left body to form a stop flange. Effectively

GFE's many years of ball valve manufacturing experience combined with international advanced technology designed a double-line sealing structure, which can naturally relieve the valve seat and ensure reliable sealing under high low pressure and vacuum environments. When the medium pressure is operating in the low pressure area, the contact area between the valve seat sealing ring and the ball is small, so there is a larger sealing specific pressure to ensure reliable sealing of the valve seat. When the medium pressure runs at a higher level, the valve seat sealing ring and the ball The contact area of the valve is increased, so the valve seat sealing ring can withstand a larger medium thrust to ensure that the valve body is not damaged.

For the ball valve with very low working pressure, considering that the medium pressure cannot ensure the reliable sealing of the valve seat and the pre-tightening force declines after long-term use, so for the low pressure, ultra low pressure or vacuum working conditions, the ball valve is used and the leaf spring is loaded.

The sealing structure of the valve seat ensures the long-term and reliable sealing of the ball valve.

The seat sealing structure of medium and high temperature ball valves uses parapolystyrene as the sealing ring and can be used at a temperature of 300°C, while the ball valve with a metal seal and high temperature resistant composite material structure design can be used at higher temperatures. This structure has a one-way sealing function.

When the medium in the middle cavity of the valve changes due to the pressure of the piping system or the temperature of the medium, and the pressure in the middle cavity rises abnormally, the medium in the middle cavity can rely on its own thrust to push the valve seat to automatically release the pressure, thereby ensuring the valve Security.