Sealing Gaskets : Sealing gasket / Gasket is placed in between two objects in order to prevent leakage of any kind or pressurized & non pressurized media.
At Sam Engineers, special attention is given on the compression set of a sealing gasket / gasket to adapt to flange / mating parts irregularities and to any dimensional changes of the flange / mating part system caused by temperature changes during operation.
The gasket requires resistance against media and temperature within the range of given application.
Requirements for a excellent Sealing Gasket / Gaskets are:
- Good compressibility and face adaptability
- Good recovery
- Limited relaxation
- Chemical resistance
- Temperature resistance.
Classification of Gaskets in two categories
- Metallic & Semi metallic Gaskets.
- Non Metallic Gaskets.
Non Metallic Gaskets can be further classified into
- Rubber Gaskets
- PTFE Gaskets
- Asbestos / Non Asbestos Gaskets
- Graphite Gaskets
- Fibre Reinforced Gaskets.
Rubber Gaskets :
Rubber gaskets are cut / punched or molded to shape from industrial manufactured rubber sheets / compounds made from industrially produced rubber.
Most versatile material for Gaskets
- NBR - -30 to 100 Deg.C - NBR Gaskets offers good resistance to hydrocarbons & oils. Not suitable for chlorinated hydrocarbons, esters, ketones & strong oxidizing agents.
- Silicon - VMQ / PVMQ -60 to 200 Deg.C -- Silicon Gaskets offers Excellent temp. properties, unaffected by ozone & sunlight.Not recommended for hydrocarbons & steam.
- Chloroprene Rubber - CR -45 to 100 Deg.C - CR Gaskets offers Excellent resistance to oil , ozone & weathering.Suitable for moderate acids , alkalies,salt solutions, petroleum, solvents,oils & fuels.It is recommended for strong acids & hydrocarbons.
- Natural Rubber - NR -50 to 80 Deg. C - NR Gasket offers Excellent for recovery properties.Good resistance to most inorganic salts, mild acids & alkalies.Not recommended for oil & solvents or where exposure to Ozone,Oxygen or Sunlight is prominent.
- EPDM -50 to 150 Deg.C - EPDM Gaskets Offers good resistance to Ozones, Steam, strong acids & alkalies.Not suitable for solvents & aromatic hydrocarbons.
- Butyle Rubber - BR -40 to 150 Deg.C - BR Gaskets offers good resistance to ozone & gas permeation.Suitable for mild acids & alkalies, esters. Little resistance to oil & fuels.
- SBR -50 to 100 Deg. C - SBR Gaskets are suitable for weak organic acids & moderate chemicals. Not recommended for strong acids & most hydrocarbons & ozone.
- Fluoroelastomer - FKM -20 to 200 Deg.C - FKM Gasket offers excellent resistance to oils & greases ,aromatic hydrocarbons, synthetic aviation engine oils, some fire retardant hydraulic liquids.