Seat is often used in oil pumping, thermal recovery wells, sand wells, coal and other fields, its working conditions are very bad. However, tungsten carbide seat has excellent performance, so it can well adapted to the environment:
1. A good physical properties: high hardness, surface drilling fluid for shock resistance, resistance to erosion, high wear resistance, and its abrasion resistance is 15 to 20 times higher than the best high-speed steel.
2. Stable chemical properties: high temperature, anti-oxidation, anti variety of media corrosion (acid, alkali, salt, multi-gas, etc.) .
(l) Anti-corrosion. Seat sealing surface corrosion refers to the sealing surface redox reaction in the media to produce a long-term effect in the form of pitting damage, perforation, if the seat is corroded, we can not guarantee tightness. The tungsten carbide seat has excellent corrosion resistance and chemical stability, long life.
(2) Anti-scratch. Abrasions ball seat means opposite the valve seat the valve movement, the sealing surface due to friction caused by a destructive form of injury. Therefore, the seat must have good anti-abrasion performance. tungsten carbide seat has high wear resistance, high hardness, and in relative motion, tungsten carbide seat hard to wear, and thus has good sealing performance.
(3) Anti-cavitation erosion. Seat surface erosion refers to the seat sealing surface constantly being damaged by the impact of a media failure modes, fluid medium containing solid abrasive and high pressure difference between the high velocity of the fluid medium of the ball erosion is particularly serious. Seat surface cavitation refers vibration wave flowing liquid bubble burst formation damage caused by a corrupted form of the valve sealing surface. Erosion and cavitation severely damaged seal seat sealing surface and, therefore, the valve sealing surface must have anti-erosion and cavitation performance. The tungsten carbide seat just to meet these requirements.
Tungsten carbide seat life can be increased several times than ordinary steel ball valve. Obviously, for the harsh conditions of pump, tungsten carbide seat is an ideal choice.