What Types of Non-metallic Washers Are There?

PTFE Washers

Polytetrafluoroethylene gaskets, also known as Teflon gaskets, is known as the “king of plastics” polytetrafluoroethylene material (PTFE) made of gaskets, in the field of fasteners polytetrafluoroethylene gaskets are known as gaskets, “the originator”.

The special properties of PTFE gaskets stem from the exceptional performance of PTFE itself. It is a high-molecular polymer made from tetrafluoroethylene monomers, exhibiting superior heat and cold resistance, capable of long-term use in temperature environments ranging from -180℃ to 260℃. Furthermore, it is resistant to acid and alkali corrosion, as well as various organic solvents, and is virtually insoluble in all solvents. In addition to its excellent high-temperature resistance, polytetrafluoroethylene (PTFE) material has a very low coefficient of friction and good lubricity.

Polytetrafluoroethylene (PTFE) gaskets have many advantages.

• Even in an ultra-low temperature environment of -196℃, it can still maintain good mechanical toughness and retain 5% elongation.
• PTFE gaskets also have the best aging life among plastic gaskets, with a very long service life;
• The surface tension is also the smallest of all materials and will not adhere to any substance;
• Good resilience, can be in high temperature, low temperature, high vacuum, shock vibration and other cyclic alternation and a variety of harsh conditions, maintain superior sealing performance.

Natural Rubber (NR) Washers

Natural rubber washers have good corrosion resistance to weak acids and alkalis, salt and chloride solutions, insoluble in low-grade ketones and alcohols; high elasticity at room temperature; but not resistant to strong acids, poor corrosion resistance to oils and solvents, so they are not recommended for use in ozone media.

The suitable working temperature for natural rubber washers is -57℃ to 93℃.

Neoprene (CR) Washers

Compared with natural rubber, there are many synthetic rubbers, neoprene is one of them, the material washer is adapted to moderately corrosive acid, alkali and salt solution corrosion, oil and fuel have good corrosion resistance; good physical and mechanical properties, resistance to oil, heat, ozone, aging, and chemical reagents, with high tensile strength.

Neoprene washers are suitable for working temperatures from -51°C to 121°C.

Nitrile Butadiene Rubber (NBR) Gaskets

NBR is also a kind of synthetic rubber, and the washer made of it has high abrasion resistance, excellent oil resistance, good heat resistance, and good corrosion resistance to many kinds of mediums such as alkaline hydrocarbons, petroleum, natural gas, aromatic hydrocarbons and so on within the temperature range of suitable working conditions. However, its low temperature resistance and ozone resistance is poor.

Nitrile rubber washers are suitable for working temperatures from 51℃ to 121℃.

Fluorine Rubber Washers

Fluorine rubber washer has excellent heat resistance (200 ℃ to 250 ℃), media resistance and good physical and mechanical properties; also has a low compression permanent deformation, good elasticity, long service life.

The suitable operating temperature for fluororubber gaskets is -40℃ to 232℃.

Silicone Rubber Washers

Silicone rubber washers have outstanding resistance to high and low temperatures, can be used for a long time under 150 ℃ conditions, the performance will not be affected, in 200 ℃ conditions can be used continuously for 10,000 hours.

Chlorosulfonated Polyethylene Synthetic Rubber Gasket

Chlorosulfonated polyethylene synthetic rubber gaskets have good corrosion resistance to acid, alkali and salt solutions and are not affected by climate, light, ozone, oil, etc.; they have excellent ozone resistance, aging resistance, chemical resistance, heat resistance, low temperature resistance, flame resistance, abrasion resistance, electrical insulation resistance, and good physical and mechanical properties.

Chlorosulfonated polyethylene synthetic rubber gaskets are suitable for service temperatures from -45°C to 135°C.

EPDM Rubber Gaskets

Ethylene propylene rubber washers have good corrosion resistance to strong acids, alkalis, salts and chloride solutions, as well as good resistance to ozone, heat, aging, chemicals and electrical insulation.

The suitable operating temperature for ethylene propylene rubber gaskets is -57℃ to 176℃.

Graphite Washers

The diameter of graphite washer can be more than 600mm, such as large gaskets for pipelines. Graphite washers are chemically stable and have very good corrosion resistance to many acids, alkalis, salts, organic compounds, heat transfer solutions, high temperature solutions and so on. Graphite will not melt, but will sublimate when it exceeds 3316℃.

Graphite washers are used with caution in strong oxidizing media under high temperature conditions. In addition graphite can also make non-metallic winding tape in the winding washer.

Uses: Valve piping, industrial piping, electric power, mechanical petroleum, etc.

Ceramic Fiber Gaskets

Ceramic fiber gaskets are a kind of ground a full suitable for high temperature and low pressure working conditions and light flange conditions, can be used to manufacture non-metallic winding tape in the winding gasket. Ceramic fiber gaskets are light weight, high temperature resistant, good thermal stability, low thermal conductivity, and resistant to mechanical vibration.

Ceramic fiber gaskets are suitable for working temperature of 1093℃.