When using valves, FEITE gaskets are often replaced depending on the situation. There are often washers: rubber flat washers, rubber O-rings, plastic flat washers, PTFE wrapped washers, asbestos rubber washers, metal flat washers, metal shaped washers, metal sheathed washers, wave washers, winding washers and so on.
(1) Flat rubber gasket: It is easy to deform, and it is not hard when pressed. However, the pressure resistance and temperature resistance are all poor. It is only used in places with low pressure and low temperature. Artificial rubber has certain acid and alkali resistance properties, the use temperature should not exceed 60 °C; Neoprene can also resist some acids and alkalis, the use of temperature 80 °C; nitrile rubber oil, can be used to 80 °C; fluoro rubber corrosion resistance is very good, resistant The temperature performance is also better than that of individual rubbers and can be used in 150°C medium.
(2) rubber O-rings: The cross-sectional shape is a perfect circle, with a certain degree of self-tightening effect. The sealing result is better than flat washers and the pressing force is smaller.
(3) PTFE Flat Washers: The most important feature of PTFE is good corrosion resistance, and most plastics have poor temperature resistance. PTFE is the crown of plastics, but its corrosion resistance is excellent, and its temperature resistance is relatively wide. It can be used within -180°C to +200°C for a long time.
(4) PTFE gasket: In order to fully promote the advantages of PTFE, while compensating for its poor flexibility, made of PTFE wrapped rubber or asbestos rubber gasket. In this way, it is as corrosion-resistant as a flat PTFE gasket, it has good elasticity, and it strengthens the sealing results and reduces the pressing force. Its cross-section is shown in Figure 4-20.
(5) Asbestos rubber gasket: Cut from asbestos rubber sheet. Its components are 60 to 80% asbestos and 10 to 20% rubber, as well as fillers, vulcanizing agents, and the like. It has good heat resistance, cold resistance, chemical consolidation, and abundant supply, cheap prices. When used, the compaction does not have to be great. Because it can adhere to metal, it is best to coat the surface with a layer of graphite powder, so as to avoid the difficulty of disassembly.
Asbestos rubber sheet has four colors: gray, used for low pressure (brand FEITE-S200, pressure ≤ 16 kg/cm2, temperature resistance 200 °C); white, for medium pressure (feet FEITE-S350, pressure resistance up to 40kg/cm2, temperature resistance 350°C); purple white, used for low pressure (feet FEITE-S450, pressure resistance 100kg/cm2, temperature 450°C); green, for oils, good pressure resistance .
(6) Metal flat washers: lead, temperature 100 °C; aluminum 430 °C; copper 315 °C; low carbon steel 550 °C; silver 650 °C; nickel 810 °C; Monel (nickel-copper) alloy 810 °C, stainless steel 870 °C. Lead can withstand poor pressure, aluminum can withstand 64 kg/cm2, other materials can withstand low pressure.
(7) FEITE Metal Ring Gaskets:
Lens washers: Self-tightening action for low pressure valves.
Oval washers: Also low pressure self-tight washers.
Conical Double Washer: For self-tight sealing in low pressure.
In addition, there are square, diamond, triangular, toothed, dovetail, B-shaped, C-shaped, etc., which are only used in high and medium pressure valves.
(8) FEITE Metal Double Jacketed Gaskets: Metals have both good temperature and pressure resistance and good elasticity. Foreskin materials include aluminum, copper, low carbon steel, stainless steel, Monel, and others. Inside the filling material is asbestos, PTFE, glass fiber and so on.
(9) Corrugated Gaskets: Features low compaction force and good sealing results. Often adopts a combination of metal and non-metal modes.
(10) FEITE Spiral Wound Gaskets: A very thin metal band and non-metal band are closely attached together and wound into a multi-layered circular shape with a wavy cross-section and good elasticity and tightness. The metal strip can be made of 08 steel, 0Cr13, 1Cr13, 2Cr13, 1Cr18Ni9Ti, copper, aluminum, titanium, and Monel alloys. Non-metallic materials include asbestos and PTFE.
———-CiXi Feite Sealing Material Co., Ltd.
