Rotating Disc Valves
Rotating Disc Valve get a quick open or close through the rotating motion of valve disk, it is designed specially for the abrasive and erosive material and it can operate properly and continuously under critical condition for long time.
The rotating disc valve still has features of self-rotary and self-grinding. It changes the rotary drive into linear drive, so it has lower installation cost. Always the stem packing of linear-type valve is scratched , but for the rotating disc valve the possibility of external leakage is reduced effectively due to the spring-loaded packing. This prolongs the service life of the packing. The valves can offer bi-direction sealing for bi-direction flow, so they are widely used in the fly-ash system of power plant and other conveyance system of dry abrasive material.
A disc valve is linearly actuated to effect rotation of its sealing disc during opening and closing operations. Disc rotation is effected by creating unbalanced frictional forces between the sealing surfaces during valve operation. Rotation of the disc produces a lapping action that in the process medium renews and polishes the metal seating surfaces with each operation.
The rotating disc valves feature a unique rotating or shearing disc which provides a self lapping rotation and enhanced seat cleaning action which cuts through solids giving a long-lasting tight shut-off. The metal-to-metal seating makes the Valves abrasion resistant over a wide temperature range, and their high pressure capability, which is better than industry standards, allows the force to be distributed over a larger area resulting in reduced trim wear. An abrasion resistant full port eliminates obstruction to flow with minimal pressure drop, while the self-draining body reduces the chance of jamming due to material entrapment, stagnation and degradation. A spring-loaded connection between the disc and drive allows the disc to compensate for thermal expansion or contraction, adjusts for wear, ensures tight shut-off and resists back pressure. Additional features include body purge connections which have the ability to flush valve cavity and internals while in operation, flat seating surfaces, repairable seats and a simple yet versatile design. Typical applications include for use in media such as steam, coke, fly ash or ash slurry, flammable liquids and gases, sand and boiler water.