Pneumatic valve gasket installation considerations

only in flange connection structure or threaded connection structure, static sealing surface and gaskets via check, other pneumatic valves have been restored, it can install the gasket. (1) on the gasket, seal, gasket, thread and the bolt and nut rotating parts coated with a layer of graphite powder or pliers sulfide powder. Xx gasket, graphite should be clean and shall not be contamination ( Gasket non-stick dust bags. Graphite powder compact with stamp) Along with it, shall not be lost everywhere. Diction to correctly on the sealing gasket surface, moderate, not skewed, not into pneumatic valve cavity or shelve shoulder in Taiwan. Gasket is slightly greater than m more of inner hole, inner diameter of the gasket diameter should be smaller than the sealing surface diameter, which ensures that the hand pressure evenly. (3) sealing surface using liquid sealing gasket ( Also called no pads seal) , adhesive should be adapted to working conditions, the adhesive bonding operations in accordance with the corresponding procedures. Seal face to careful cleaning and surface treatment. Plane sealing surface should be grinding and have enough inosculation, daub is even, want to eliminate air as far as possible, rubber is commonly. ~。 Mm thick, thread seal like plane seal, contact both daub, screwing should take when vertical posture, and air out. Glue fluid is unfavorable and overmuch, lest overflow pollution other pneumatic valve. (4) when the thread sealed with teflon thin film ribbons, will have to chat with first beginning stretched thin some, on the thread and then jiang first get rid of redundant ribbons, make on the thread of mulberry film forming is woven. Thread clearance, generally around one to two laps, miserably around the direction should be consistent with threaded to, the terminal will overlap the beginning, gradually snap ribbons, is woven in form, which can ensure miserably around the thickness of the uniform, screwing in the former, the threaded end of the film pressure under the unity, so that the ribbons be screwing in the screw hole with thread, screwing in slower, forcibly even appropriate, don't loose after tightening, avoid by all means avoid cyclotron, otherwise easy to leak. 5] a gasket sealing surface shall install only, do not allow to install two or more pieces between the sealing surface pads to make up for a lack of clearance between the sealing surface. [6] trapezoid ( The ellipse) Gasket installation should make gasket contact inside and outside the circle, the two surfaces of the gasket may not be in contact with the sealing groove bottom. Once the installation of the o-ring in addition to circle and slot should comply with the design requirements, appropriate amount of compression. Hollow metal o-ring is generally the most matters of flattened degree for % ~ %, the compression deformation rate of the rubber O ring, cylinder on static seal take % ~ %, plane take % ~ % static sealing surface. For higher internal pressure and vacuum sealing, thrown some compression degeneration. On the premise of guarantee seal, compression deformation rate as small as possible. Can prolong the life of the o-ring. O-ring installation method as shown in the packing of installation and removal section. After being in the pneumatic valve flange sealing gasket set up, install pneumatic valve cover before, should make pneumatic valve stem is in the open position, lest affect installation and damage the pneumatic valve. Capping aim to position, shall not be adjusted by means of push and pull, so as not to scratch pads and pull move. Adjust the pneumatic valve cover shall be filed slowly, and then gently down. 'levies on the bolt, the steel grade tag should be put on one side of the convenient check, at the end of the should be symmetrical, take turns. Screw down the bolt equably, points to tighten, bolts shall be filled with clasp, neatly without loose. Threaded connection spacer gland, such as a wrench, pipe wrench shall be used. The bolt connection or threaded connection pads in a horizontal position as much as possible. ⑽ gasket pressure before, deal with the nature of the pressure, temperature, medium. Know the characteristics of the gasket material, determine the pre-tightening force general gaskets, metal materials such as rubber asbestos, flexible graphite, rubber, plastic and other mat is lower than prestressing force of metal pads, compound the material in the middle. In non-metallic gaskets, rubber asbestos gaskets gasket pre-tightening force than that of the other material be larger. The lowest is rubber. Screw down the bolt it is best to use the torque wrench. Pre-tightening force due to ensure the test without leakage, small as far as possible. Too easy to break pretightening gaskets, gasket urban resilience. ⑾ gasket after compaction, should guarantee the fittings, with adequate clearance between leakage for gasket pressure. Spacer reserved clearance. ⑿ under high temperature conditions, the bolt will be due to the high temperature creep and stress relaxation, degeneration, the static seal leakage, at this time should be in hot press tight gasket. On the other hand, the bolts under the condition of low temperature working condition, can produce contraction, static sealing gasket load is too large, easy to crush gaskets, bolts in cold cases should be appropriate to unscrew. Pipelines and pneumatic valve, high and low temperatures in the driving test, heat and temperature of the international. Heat some units for tight and unfavorable international temperature regulation, basically the same, according to their respective standards.