PTFE gasket or back up ring

09-03-2020

PTFE gasket or back up ring

The full name of PTFE gasket or back up ring is polytetrafluoroethylene gasket. It is also called PTFE gasket or Teflon gasket in foreign countries. It is a flat gasket made of PTFE rod, tube and plate by mechanical turning or cutting , V-shaped gasket, piston ring, ball valve gasket, etc. In fluid machinery (such as pumps, compressors, mixing tanks, centrifuges, etc.), the parts with the most severe operating conditions are considered to be PTFE gaskets or back up ring.

hydraulic seal

Introduction of PTFE gasket

The full name of PTFE gasket is polytetrafluoroethylene gasket.  With good characteristics of corrosion resistance, aging resistance and non-conductivity. Polytetrafluoroethylene pH 0-14 (except for molten alkali metal and fluorine under high temperature and pressure). It can have good mechanical strength between -100 ° C and 100 ° C.

The importance of PTFE gasket

Teflon gasket or back up ring harshness

In fluid machinery (such as pumps, compressors, mixing tanks, centrifuges, etc.), the parts with the most severe operating conditions are considered to be PTFE gaskets.

seal manuafacture

(1) Accept axial force like thrust bearing;

(2) Dissipate the generated heat like a radiator;

(3) In the case of high temperature and high pressure and easy corrosion, static sealing is now very difficult. It is even more difficult to complete dynamic sealing on a sealing surface of a few millimeters in high-speed rotation.

PTFE gasket working environment

(1) Without the auxiliary system, it can only improve the sealing layout and improve the raw materials. (High cost, cannot solve the problem fundamentally)

(2) In practice, there is almost no PTFE gasket without any auxiliary equipment. For example, high-pressure tandem PTFE gaskets and high-temperature PTFE gaskets must use corresponding auxiliary equipment.

(3) (via auxiliary system) the severe working conditions become sealed and acceptable working conditions. (The role of PTFE gaskets has been greatly improved, the application range has become more extensive, the need for sealing itself data has been reduced, and the cost of PTFE gaskets has been reduced)

PTFE gasket or back up ring control

Excessive end-face conflict heat has the following damage:

(1) Liquid film vaporization aggravates seal failure;

(2) Thermal deformation of the end face increases leakage and wear;

(3) Aggravate corrosion;

(4) Auxiliary seals age and degenerate and then fail;

(5) The graphite impregnated material is carbonized or melted to cause leakage.

Therefore, the temperature rise of the end face is the enemy of PTFE gaskets.

Teflon gasket auxiliary system

(1) Reduce the temperature rise and adhere to the outstanding smooth surface. (Make the parts of the PTFE gasket outstanding and work normally)

(2) (in easily vaporizable media) insist that the pressure in the sealed cavity is higher than the full vapor pressure so that it does not vaporize.

(3) Insulation heating in a cryopump.

(4) Regarding the crystallization of solid particles and the sealing of strong corrosive media, the seal can be maintained without damage.

5. Under better working conditions, the use of the auxiliary system will improve the sealing stability and service life. (Some sealing operations are not too high in temperature, pressure, and speed. It can be operated without auxiliary systems)

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6. The auxiliary system is part of the PTFE gasket

We are hydraulic seal and PTFE gasket and PTFE back up ring manufacture and supplier, if you have any special size of hyd cylinder seals or piston ring or rubber seal, seal ring, o ring seal,hydraulic seal, rotary seal, o ring manufacturers, pneumatic seals and other different kinds of seal design, you could visit our online website http://www.wonepart.com/product/back-up-ring 

 pls feel free to contact us via email info@wonepart.com or whatsapp:+86-15860751932. We will offer you best price with high quality.

hydraulic seal 

References

Science Encyclopedia Engineering Technology


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