A thin layer of material placed between two surfaces or joints to make a tight seal.
A good gasket has the following properties:
- good compressibility
- good face adaptability
- good recovery
- limited relaxation
- chemical resistance
- temperature resistance
Depending on the application there are other properties that may be important, such as:
- good shelf life
- electrical isolation
- Butyl rubber - good sealing for gases, poor resistance to oils and fuels.
- Carbon Fibre - good thermla conductivity and high temperature capable. Can be used in pH 0-14. Not suitable in oxidizing environments
- Cork - compresses easily with negligible lateral flow, relatively inert but lacks flexibility and strength
- Flexible graphite - wide chemical resistance and suitable for oxidizing environments
- Mica - highly flexible and elastic with excellent thermal and chemical resistance
- Natural rubber - excellent recovery and good resistance to most inorganic salts, mild acids and alkalis. Not suitable for use where there are oils, solvents, ozone, oxygen or sunlight.
- Neoprene - excellent where there are oils, ozone and weathering, ok with moderate acids, alkalis, salts, petrol, solvents, oils and fuels.
- Nitrile - better chemical and temperature resistance compared to Neoprene.
- PTFE - excellent chemical resistance, anti-stick and dielectric property. High compressibility, but prone to relaxation and creep
- Silicone - excellent temperature properties, not affected by ozone or sunlight. Not suitable with hydrocarbons or steam
Subjects: Mechanical Engineering