Common sense of HVAC: Structure characteristics of electric shut-off valve

Common sense of HVAC: Structure characteristics of electric shut-off valve 1. There is no conflict between opening and closing. This function completely solves the problem of traditional valves affecting the sealing due to the mutual impact between the sealing surfaces of the assembled mechanical seal. 2. Top-mounted structure. Grundfos mechanical seals of valves installed on pipelines can be directly viewed and repaired online, which can effectively reduce equipment parking and reduce costs. 3. Single valve seat planning. Eliminates the question that the mechanical seal of the medium inlet of the valve cavity will affect the safety of operation due to abnormal pressure increase. 4. Low torque planning. The valve stem with a special structure can be easily opened and closed with only a small handle. 5. Wedge-shaped sealing structure. The valve relies on the mechanical force supplied by the valve stem to press the ball wedge onto the valve seat to seal, so that the sealing performance of the valve is not affected by the change of pipeline pressure, and the sealing function is reliably guaranteed under various working conditions. 6. Self-cleaning structure of the sealing surface. When the ball is tilted away from the valve seat, the fluid in the pipeline will pass through 360° uniformly along the sealing surface of the ball, which not only eliminates the flushing of the valve seat by the high-speed fluid, but also washes away the accumulation on the sealing surface to achieve the intention of self-cleaning . 7. The valve body and bonnet with valve diameter below DN50 are die forgings, and the valve body and bonnet above DN65 are steel castings. 8. The connection methods of the valve body and the bonnet are different, clamp pin shaft connection, flange gasket connection and self-sealing thread connection. 9. Plasma spray welding or surfacing welding of cobalt-chromium-tungsten carbide is selected for the sealing surface of valve seat and valve disc. The sealing surface has high hardness, wear resistance, scratch resistance and long service life. 10. The material of the valve stem is nitrided steel. The nitrided valve stem has high surface hardness, wear resistance, scratch resistance, corrosion resistance and long service life. Keywords: Grundfos mechanical seal, imported mechanical seal, cartridge mechanical seal