1. Graphite gasket
Flat gasket made of soft graphite, suitable for high temperature and strong corrosive medium.
2. Metal gasket
There are three main types:
1) Octagonal and oval gaskets - suitable for trapezoidal groove flange sealing surfaces;
2) The tooth method is to process the bevel-shaped corrugations on the sealing surface of the metal flat gasket - suitable for the sealing surface of high and low flanges;
3) Lens pad - suitable for lens flange sealing surface.
Metal gaskets are available in various materials such as pure iron, extremely mild steel, stainless steel, and aluminum.
The machining accuracy and surface roughness of the metal gasket sealing surface are very high, and the bolt pressing force is very large, which is used in high temperature and high pressure valves.
3. Metal clad graphite gasket
Made of thin metal clad annular asbestos gaskets. Usually used on high and low flange sealing surfaces. Valves for higher temperatures and pressures.
4. Surrounding gasket
It is surrounded by a mixture of corrugated metal belts and sealing material belts. There are steel belt-asbestos, steel belt-polytetrafluoroethylene, steel belt-flexible graphite and so on. Usually used for high and low flange sealing surfaces. Suitable for medium pressure valves at higher temperatures.
5. PTFE gasket
Usually used for tongue and groove sealing surface, there are mainly two kinds of materials: PTFE and glass fiber PTFE. It is suitable for strong corrosive media at lower temperature and various pressures.
6. Asbestos rubber gasket
It is suitable for lubricating flange sealing surface, high and low flange sealing surface and tongue and groove flange sealing surface. The advantages are good corrosion resistance and thermal stability, good plasticity, and use a small compression force to ensure sealing. The disadvantage is that the strength is low and it is easy to stick to the flange sealing surface. Asbestos rubber gaskets include all-round asbestos sheets, anti-corrosion asbestos sheets, usually asbestos sheets, acid-resistant asbestos sheets, oil-resistant asbestos sheets, metal wire asbestos sheets and other materials. For higher temperature medium pressure valves.
