Introduction:
Rubber gaskets are widely used in very large scope and composed different kinds of materials to become synthetic rubber. It has excellent compressibility and recovery. It plays good function under the work situation with lowest bolt-load; it won’t split after removed from the flange. Rubber gaskets can keep good sealing function even though the flange is damaged and not plain and smooth. As rubber has the property of special expand and permeate resistance, it plays the effectiveness sealing role to resist gas and liquids to through and formation.
The properties and classification of RUBBER

Code of rubber	Material	Hardness	Temperature scope Min.         Max.
NR	Natural Rubber	65	-70          120
CR	Neoprene	70	-40          121
NBR	Nitrile	80	-59          121
IIR	Butyl	80	-59          121
FKM	Viton	75	-20          205
EPDM	Ethylene Propylendiene	80	-57          150
SBR	Styrene Butadiene	80	-40          100
SI	silicone	70	-55          210