The assembly is not resistant to corrosion The mechanical seal is the reason that affects the cracking of the ceramic ring Mechanical seal

Over-tight assembly of ceramic rings is the main cause of cracking, and assembly of mechanical seals that are not resistant to corrosion is also a common cause.

Due to the difference in linear expansion rate between the coating material and the base material, cracks will appear on the surface of the ring when the temperature rises and the dyeing and finishing mechanical seal is high, especially for stellite alloys. Among the more advanced coating materials, cobalt-based tungsten carbide is inferior to nickel-based coatings. Cooling the mechanical sealing surface can effectively prevent thermal cracking. The solid particles remaining on the sealing surface often damage the surface. Crystallines are formed between the faces, and after regrinding the graphite ring, the abrasive will be embedded in the surface of the graphite ring.


The failure of the rubber ring is related to the application method. Usually, high pressure is one of the reasons for the failure of the compressed O-ring. When the O-ring is found to be rectangular or the ring becomes hard, it is necessary to adjust the compression, otherwise it will generate heat.

So it is necessary to inquire about the application temperature of a synthetic rubber. Most of the swelling of synthetic rubber rings is caused by chemical corrosion. They all have their own characteristics. For example, fluorine rubber is resistant to high temperature, while ethylene and propylene O-rings will swell when they are used in kerosene lubricating oil. Rubber has erosive effect, so NBR products should not be installed in electric motors, so high temperature and chemical corrosion are usually the main reasons for hardening and cracking of rubber products.