How about the valve gasket?
(3) sealing surface adopts liquid sealing valve gasket (also known as no gasket seal), the adhesive should be adapted to the working conditions, bonding operation in line with the corresponding bonding procedures. Valve sealing surface should be carefully cleaned or surface treatment. Plane sealing surface should be ground and have enough degree of agreement, apply to even try to eliminate air layer is 0.1~0.2mm thick, with thread sealing plane seal, contact the two surface to be coated, shall be screwed into the vertical posture, in order to discharge the air. Glue should not be too much, so as not to overflow pollution of other valves.
(4) when the thread sealed with teflon film with raw materials, the raw materials with the beginning at stretching and thinning, pasted on the thread surface, and then start with to get rid of excess raw material, to make the film close to the thread forms a wedge as the thread gap, generally one to two ring winding, the winding direction should be with the screw, the terminal will start at the coincidence, gradually breaking with raw material, make into wedge, so as to ensure the winding thickness, the screw thread ends before the film pressing, so that together with raw materials with thread is screwed in the screw, screw, hard to slow even appropriate, don't tighten loose, avoid the roundabout, otherwise easy to leak.
(2) valve gasket installed on the sealing surface to be correct, moderate, can not be skewed, can not extend into the valve chamber or on the shoulder. The valve gasket sealing surface is slightly larger than the hole diameter, valve gasket diameter should be slightly smaller than a sealing surface diameter, so as to ensure uniform compression.
Only when the flange connection structure or thread connection structure, the static sealing cover and the gasket are checked correctly, other valve fittings can be installed with the valve gasket after the repair is completed. (1) on the front of the valve gasket, the sealing surface, gasket, thread and bolts, nuts, rotating parts coated with a layer of graphite powder or molybdenum disulfide powder. Gaskets, graphite should be kept clean, shall not stain (gasket bags are not sticky ash; graphite powder boxed, stamped), with the use of, shall not be thrown everywhere.
