High temperature high pressure power station valve stem to prevent leakage at the media, the general stuffing seal

High temperature high pressure power station valve stem to prevent leakage at the media, the general stuffing seal. And under conditions effective sealing of use conditions, and the use of appropriate packing filler form. Also requires a certain degree of plastic filler, under the pressing force can produce a radial force, and in close  2 way manifold  the shaft. Should have sufficient chemical stability, do not pollute the media, the media is not bubble up, does not corrode the valve stem, low  Instrument valve manifold . Stem a small amount of eccentricity, the filler should be enough floating flexibility. Filler additive does not dissolve the medium, is simple to manufacture, easy loading. Principle of the gland packing in the stuffing box packing axially compressed to produce the plastic filler radial force and close contact with the shaft. Meanwhile, the lubricant added to the filler material is extruded to form a film between the contact surfaces. Due to the uneven contact state, the contact parts appear boundary lubrication, does not contact the recessed portion is formed a small tank with a thicker film. When the relative movement of the filler shaft, with the contact portion does not contact a portion consisting of irregular labyrinth play to prevent fluid leakage effect.