The performance of the double eccentric hemisphere valve, structure features and application range
With 1, an overview of the development of industry, is especially high temperature and high pressure condition for ball valve gate valve gate is more and more big, the demand for ball valve door with wear-resisting, scouring resistance, high temperature resistant and corrosion resistant performance is higher. And although its traditional full size ball valve door, valve seat after welding, spraying technology of surface hardening treatment, but its service life, cost and performance still cannot satisfy the use requirement, such as industrial silicon, coal chemical, blast furnace gas, gas and other harsh working conditions. Double eccentric hemisphere is learned the different structure of ball valve gate valve, V and track ball valve gate valve advantages to develop new products. Ball valve door with double eccentric sealing structure, wear small, small torque, good sealing performance, long service life. Valve seat and half sphere with special hardening process, especially to adapt to the harsh working conditions is resistant to wear and tear, scouring resistance, corrosion resistance, high temperature resistant requirements. 2, structure features. 1 and half sphere double eccentric side of the valve and ball with double eccentric design, reliable sealing effect, instantaneous release, torque is small, long service life. Can be used in the harsh conditions of transport granule medium. Its structure principle is half sphere center line and the valve rod line offset size a, and the valve seat centerline offset size b, the spheroid and the valve seat completely withdraw when fully open, and there is a certain gap, radius of gyration is divided into long radius and short radius, in long radius turn the trajectory of the tangent and the valve seat sealing surface to form a & theta; Angle, when the door opening and closing of the valve, hemisphere has a relative to the valve seat surface coming out from the opening 10 & deg; , the core is fully separated from and gradually into the effect of extrusion, which reduces the open/close the valve seat between the hemispheres and mechanical wear and scratches, improve the service life. 2. 2, the valve seat ( 1) Valve seat adopt floating design, reduces the processing difficulty, ensure that the valve seat centerline and half sphere center of sphere overlap, thus improve the sealing performance. Have clearance d valve seat and valve body, using half a sphere position during assembly can automatically find the midline, ensure that the valve seat sealing surface contact with half sphere spherical, solve the error caused by leakage due to machining accuracy, improve the using performance and life of ball valve door. ( 2) Seal between the valve seat and valve body adopts hard seal structure, suitable for high temperature and high pressure conditions. Valve seat and valve body sealing interface dimension c value is small, each sealing surface accuracy requirement is high, when assembling, retainer with electric impact wrench installation, mesh is not only a retainer with the valve body, prevent loose, and the valve seat friction rotation, in line with the mechanical vibration meshing principle, reliable sealing valve seat and valve body. ( 3) The valve seat and valve body and valve seat and half sphere with two hard seal, so the valve can be used in high temperature and high pressure conditions. 2. 3, other parts of valve door overall adopting modular design, simple structure, good reliability, high universality. The valve rod using the jet structure. Drive way diversification, the valve rod, bracket and connection of the actuator size with ISO5211 standard, can be directly with various specifications actuators piece together. Commonly used driving mode has manual, pneumatic, hydraulic, electric and gas liquid linkage, thus improve the performance of double eccentric hemisphere valve use. 3, use double eccentric hemisphere valve with the valve is suitable for all kinds of common industry demands, such as water, sewage, waste water, steam, gas, pulp and other media. If the seal the Cr - Mn- Si carbide and fireproof, explosion protection and anti-static function, is suitable for high temperature medium in requirements, such as gas, coke oven gas, water gas and natural gas, etc. If the seal ( Half sphere and valve seat) And valve through tungsten carbide special craft processing, the runner has high efficiency and energy saving, good abrasion resistance, reliable sealing performance, convenient operation, opening and closing fast, long life and other advantages, is the industrial choice of silicon industry with the valve in the pipeline. Because of its half sphere and valve seat in an instant from and instantaneous pressure characteristics, suitable for medium containing particles of harsh working conditions, can be widely used in metallurgy, mineral processing, the power of pulverized coal in the production process, such as the coal pulverizing system and the cleaning of all kinds of line control. In the process of instant detachment and instantaneous pressure, cut half sphere and valve seat are crowded role can remove scale and adhesive on the surface of the seal, can ensure reliable sealing tightness. Precipitation is conveying easy scaling, the precipitation crystallization solution slurry and slurry ash two-phase mixture fluid medium in the process with the choice of valves. 4 and conclusion at present, various specifications double eccentric side of the valve has been applied in different industries on various projects, good effect, and gradually expand the scope of use.