Pneumatic valve's sealing device

when brake pneumatic valve, globe pneumatic valve, throttle valve in the closed state, because of the pneumatic valve, pneumatic valve throttling of flow direction of medium to flow up from below the pneumatic disc, so no pressure in the body cavity, brake the pneumatic valve closed cavity pressure is lower than work pressure, so the medium pressure on packing is very small.
when open, the packing place is about to work under pressure, and if there is the sealing structure, can prevent the working medium pressure ACTS on the packing, prolonging the life of the packing, the pneumatic valve leakage does not occur. Its role is another, sealing packing leakage, can all open the pneumatic valve, make the seal on the seal, so that you can loosen the packing gland and packing gland, increase filler, compaction fill gland again, to ensure that the packing place of pneumatic valves, no leakage phenomenon, therefore, pneumatic valve, the gate by the pneumatic valve, throttle valve to regulations on sealing device.