Fireproof and anti-static ball valve is a kind of pipeline that can be used for natural gas, artificial gas, liquefied gas, city gas and non-corrosive gas. It has anti-static and fire protection devices, that is, it is installed between the ball and the valve stem, the valve stem and the valve body.
Fire-proof Structure :
Whether it is a floating ball valve or a trunnion mounted ball valve, the principle of the fire-proof structure of the valve seat is the same.That is, the ball valve adopts a double seal design. When the soft seal is melted due to high temperature, the valve core ball is redesigned to form a right-angle hard seal with the soft seal behind, forming a sealing relationship again.
For floating ball valves, the pressure of the medium makes the ball contact the valve seat. For the trunnion mounted ball valve, the elastic force of the elastic valve seat is mainly used to make the valve seat contact with the ball to achieve sealing.
The metal sealing surface on the valve seat only acts as a temporary seal. Although the sealing requirements are not too strict, there are still certain processing requirements that should be processed into spherical or inclined surfaces. If it is made into a spherical surface, its radius of curvature should be the same as that of the sphere, and the edges and corners of the sealing surface should be rounded to avoid damage to the smoothness of the sealing surface on the surface of the sphere during assembly and disassembly.
Anti-static structure:
As long as one of the valve sealing pairs uses an insulator, static electricity will be generated due to friction during the up and down or rotation of the sealing pair. Since the insulator has the danger of accumulating static electricity, the static electricity can cause sparks, and the sparks may cause the explosion of the medium. Therefore, in order to effectively prevent the generation of static electricity, it is necessary to conduct electricity between the ball, the valve top, the valve stem and the valve body, so as to dissipate the static electricity. lead out.
The conductive spring causes the static electricity generated during the valve opening process to be introduced into the pipeline through the set static electricity channel, so as to achieve the purpose of eliminating static electricity. Avoid static sparks and ignition of flammable media to ensure system safety.
Fireproof and anti-static ball valve is compared with conventional ordinary ball valve. It will be used in many industries and its safety performance has also been greatly improved. For occasions prone to fire, it can effectively prevent internal leakage. The realization of this function mainly depends on the ball valve sealing ring, which is a double-layer seal, a soft seal and a metal seal. When the soft seal layer is burned out, the metal seal can further fill the void and play a key alternate sealing role. It can prevent large media leakage and fire spread.
When the fireproof and anti-static ball valve is opened and closed, friction will occur between the ball and the valve seat, and the static electricity generated by the friction will accumulate on the ball. Ball valves used on gas, fuel and chemical lines do not allow this. , may cause a pipeline explosion accident. The anti-static structure of the ball valve is equipped with an electrostatic discharge device, which can export the electrostatic charge accumulated in the ball at the first time, effectively ensuring the safe operation of the pipeline;
It should be noted that the fire prevention and anti-static functions of the ball valve are not omnipotent. They can only play an emergency role, giving more time to resolve the accident. In addition to the use of fire-proof and anti-static ball valves, oil and gas pipelines should also be equipped with certain explosion-proof, fire-proof and other fire-fighting measures, and strictly abide by relevant national regulations.
Post time: Nov-15-2022