Count! Gasket installation requirements
As the interval two kinds of fasteners used gasket can also be used to distribute load thread fasteners installed in the use of certain requirements, otherwise it will directly affect the use of effects fastener between two objects, even early damage caused by fasteners, depending on the installation requirements of its different characteristics are also different.
First, the gasket installation requirements
1, the gasket and flange sealing surface should be clean, without any impact on the performance of joint seals scratches, spots and other defects.
2, the gasket outer diameter is smaller than the outer flange sealing surface, the sealing gasket inside diameter slightly larger than the inner diameter of the pipe, the inner diameter difference between two generally take two times the thickness of the gasket, to ensure that after compression, sealing gasket without extending into the container or the inner edge of the pipe, duct or vessel not to hinder the flow of fluid.
3, gasket preload should not exceed the design requirements, in order to avoid excessive compression gasket lose resilience.
4, when the gasket compression, preferably using a torque wrench. Large bolts and high-strength bolts, preferably using a hydraulic tightening device. Tightening torque should be based on a given gasket pressed by calculation, the size of the hydraulic tensioner hydraulic pressure should be determined by calculation.
5. When installing the gasket, the order should tighten the nut. But should not twist once reached the design value. Usually at least 2 or 3 times a cycle, in order to gasket stress distribution.
6, pressure vessels and piping for flammable, explosive medium facelift gasket should be used security tools, so as to avoid the tool flange or bolts collide, sparks and cause a fire or explosion.
7, if the pipeline leaks, antihypertensive treatment must then replace or adjust the installation gasket, non-pressure operation.
Second, the gasket special installation requirements
1, the installation and projection plane sealing flange mating spiral wound gasket should be taken to ensure that the seal with the concentric pipes, the general outer reinforcement ring and bolt inside circumferential surface contacts to locate, allowed eccentrically mounted. When installing tongue and groove sealing surface of the flange of the basic type spiral wound gasket, attention should be consistent with the clearance groove wall.
2, the installation width of a narrow metal coated gasket should be placed outside a certain thickness of the spacer plate, and then pressing the flange, so as not to cover the filler metal gasket inside pressure, the metal casing of the interface (or take the mouth) expansion open, damaged metal-coated pads.
3, when the flange temperature higher than 200 ℃, between the gasket and flange sealing surface should be coated with sealant to prevent gasket and flange sealing surface at high temperature sintering, to increased maintenance and replacement gasket trouble.
4, the sealing surface is not flat, can be coated with sealant and then install the gasket sealing surface. Sealants generally composed of manganese dioxide, lead, linseed oil (drying oil) composition after graphite and survived. You can choose the appropriate type and grade of liquid sealant in accordance with the sealing medium, medium temperature and pressure conditions.
5, for installation octagonal metal ring gasket, when the metal ring gasket and flange sealing groove machining is not ideal, it can be achieved with research through close contact. For large diameter metal ring gasket, with research more difficult, in order to fill the tiny metal surface uneven, use sealant.