Natural rubber is suitable for water, sea water, air, inert gas, alkali, salt aqueous solution and other media, but not resistant to mineral oil and non-polar solvents, long-term use temperature does not exceed 90℃, low temperature performance is excellent, can be used above -60℃.

  Nitrile rubber is suitable for petroleum products, such as petroleum, lubricating oil, fuel oil, etc., long-term use temperature is 120℃, such as in hot oil can withstand 150℃, low temperature is -10~-20℃.

  Neoprene rubber is suitable for seawater, weak acid, weak alkali, salt solution, excellent resistance to oxygen and ozone aging, oil resistance is inferior to nitrile rubber and better than other general rubber, long-term use temperature below 90℃, maximum use temperature does not exceed 130℃, low temperature is -30~-50℃.

  There are many varieties of fluorine rubber, they have good acid resistance, oxidation resistance and oil resistance, solvent resistance. Can be used in almost all acid media as well as some oils and solvents, long-term use temperature below 200℃.

  Rubber sheet as a flange gasket, mostly used for pipelines or often disassembled manholes, hand holes, the pressure does not exceed 1.568MPa. Because in all kinds of gaskets, rubber gaskets are the softest, good bonding performance, and can play a sealing effect under a small pre-loading force. Because of this, when subjected to internal pressure, it is easy to be squeezed out due to the thickness or low hardness of the gasket.

  Rubber sheet used in benzene, ketone, ether and other organic solvents, easy to appear swelling, weight gain, soft, sticky phenomenon, resulting in seal failure. Generally, if the swelling degree exceeds 30%, it cannot be used.

  In the case of low pressure (especially below 0.6MPa) and vacuum, the use of rubber pads is more suitable. The rubber material has good density and low permeability. For example, fluorine rubber is most suitable for sealing gaskets of vacuum containers, and the vacuum degree is up to 1.3×10-7Pa. When the rubber pad is used in the vacuum degree range of 10-1~10-7Pa, it needs to be baked and pumped.