Metal corrugated pipe valve has been widely used, such as corrugated pipe gate and corrugated pipe cut-off valve, corrugated pipe ball valve, etc. Corrugated tube structure will stem in gland in dynamic seal into valve rod in the valve cover of static sealing, valve seal more safety and reliable.
Metal corrugated pipe valve corrugated pipe bottom is welded to the valve stem, in order to prevent the process fluid etching stem, the other end in between body and cover constitutes a static seal. Use appropriate materials, bellows valve can be used for high temperature 500 ℃ and high pressure 2500 ib (42 mpa) in the condition. Usually the valve stroke for corrugated tube free length of 15%, thus bellows occupy a lot of pressure space, manufacturing process is rather complicated, the price is more expensive. But with the traditional packing seal than valve, corrugated pipe valve stem seal more reliable, outer leakage demand is strict occasions, such as poisonous medium, strong corrosive medium and radioactive medium and hot oil and so on is used widely.
The top of the corrugated pipe flange and graphite gasket, valve cover and support form static seal, make the body of the medium and external isolation. The body of the medium not by the stem and packing box have clearance and leakage. If because of special circumstances cause corrugated tube rupture, valve upper gland still can have emergency action. Stem upper along the axial processing two straight flute, dial the pin the valve stem can only move along the shaft up, and not along the radial rotation. Stem lower processing two spiral groove, dial the pin fixed in the sphere, dial the pin can be in spiral slot free to move.
 

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