Detailed knowledge of the mechanical seal corrosion protection

The mechanical seal special structural form and the working environment and conditions, corrosion damage morphology are also diverse . PTFE seals, PTFE gasket seals and other mechanical damage to the main form of common corrosion damage , thermal damage and mechanical damage. Where corrosion damage greater harm .
A metal ring corrosion
1 , uniform surface corrosion. If the metal ring surface contact with corrosive media , and the metal itself impatience corrosion , it will produce surface corrosion , and its phenomena are leaks, early wear and tear , damage, sound and so on. Uniform corrosion of metal surfaces and non- film forming two forms , free film very dangerous metal corrosion , stress corrosion cracking is called , the choice of surfacing alloy and cast iron , tungsten carbide, titanium carbide seal ring , prone to stress corrosion rupture. Etching process with a constant speed , so that galvanic corrosion intensified.
2 , stress corrosion cracking. Metal corrosion and tensile stress at the same time under the effect of wear resistance. Corrosion fill F4 ring filled mainly refers selective etching , stripping damage or deterioration . If the hydrofluoric acid , the glass fiber molecule hot corrosion , these cracks communicate the seal faces , accelerated wear of the end face , an increase of leakage .
Two non-metallic corrosion ring
1 , graphite ring corrosion. Enterprise Information Network mentioned impregnated with resin impervious graphite ring , its corrosion for three reasons: First, when the face overheating when the temperature is higher than 180oC , to break away from the resin impregnated graphite ring , the ring wear down ; Second, if the resin impregnated inappropriate choice , so cable security seals cooling system establishment , which is mainly caused by the mistakes selection . The corrosion film , the passivation film characteristics generally has a protective effect , but the metal material used for the sealing ring , such as stainless steel , cobalt -chromium alloy such as a passivation film on the surface friction of the end face destruction , under hypoxic conditions New film is difficult to generate , select corrosion resistant impregnating resin , the use of high pressure impregnation , impregnation depth increase is necessary .
2 , the oxidation of the graphite ring . In an oxidizing medium, the end face or poor cooling in the dry friction generated when a temperature of 350 ~ 40o ℃ graphite ring can react with oxygen to produce CO, gas , can face becomes rough, or even rupture. Metallic ring , while chemical medium and under stress , will rupture.
3 , polytetrafluoroethylene ( PTFE gasket ) corrosion of the sealing ring . Will undergo chemical changes in the medium , but also the wear resistance decreased ; third resin impregnated deep enough, when rubbed impregnation layer , abrasion resistance decreases. F4 filler such as glass fiber , the first crack in the weakened area , and then to develop in depth , to rupture , crack trailer seals sealing ring generally radially diverging type, can be one or more . Graphite , metal powder to improve its heat resistance , wear resistance. Corrosion fill F4 ring filled mainly refers selective etching , stripping damage or deterioration . Such as hydrofluoric acid , hot corrosion of glass fiber molecules , so what things should be filled , as the case may be.