Mechanical seal gasket PTFE gasket
Harshness
In fluid machinery (such as pumps, compressors, mixing kettles, centrifuges, etc.), the components with the most severe operating conditions are PTFE gaskets.
(1) Accept axial force like a thrust bearing;
(2) Dissipate the generated heat like a radiator;
(3) Under high temperature, high pressure and easy corrosion conditions, static sealing is already very difficult, and it is even more difficult to complete dynamic sealing on a sealing surface of several millimeters during high-speed rotation.
working environment
(1) Without an auxiliary system, we can only improve the sealing structure and improve raw materials. (The cost is high and the problem cannot be solved fundamentally)
(2) In actual operation, there are almost no PTFE gaskets that do not require any auxiliary equipment. For example, series PTFE gaskets and high-temperature PTFE gaskets used in high-pressure applications must use corresponding auxiliary equipment.
(3) (Through the auxiliary system) severe working conditions become sealing acceptable working conditions. (The performance of PTFE gaskets is greatly improved, the application scope is more extensive, the demand for sealing materials is reduced, and the cost of PTFE gaskets is reduced) [2]
control
Excessive end-face friction heat may cause the following damage:
(1) Liquid film vaporization and wear aggravate seal failure;
(2) Thermal deformation of the end face increases leakage and wear;
(3) Aggravating corrosion;
(4) The auxiliary sealing ring ages, deteriorates and then fails;
(5) The graphite impregnated material is carbonized or melted to cause leakage.
Therefore, the end temperature rise is the enemy of PTFE gaskets.
Auxiliary system
(1) Reduce temperature rise and keep the end surface smooth. (Make the parts of the PTFE gasket stand out and work normally)
(2) (In easily vaporized media) keep the sealing chamber pressure higher than the full vapor pressure to prevent it from vaporizing.
(3) Keep warm and provide heat in the cryogenic pump.
(4) For sealing caused by crystallization of solid particles and strongly corrosive media, the seal can be kept from damage.
5. Under better working conditions, the use of auxiliary systems will improve sealing stability and service life. (The operating temperature, pressure and rotation speed of some seals are not too high. They can operate without an auxiliary system)
6. The auxiliary system is an integral part of the PTFE gasket
Mechanical seal gasket PTFE gasket