Mechanical seal precautions to check the hard ring surface

(1) thermal cracking;

(2) ceramic ring rupture;

(3) notch;

(4) the coating off.

Ceramic ring assembly is too tight is the main reason for the breakdown of improper assembly is a more common reason.

Due to the expansion rate of the coating material and substrate material between the two lines are different, so the temperature rises, the ring surface cracks, the stellite special alloy particularly serious. In the more advanced coating materials, cobalt tungsten carbide is not as good as nickel-based coating. Cooling of the sealing surface can effectively prevent thermal cracking residue often damage the surface of the sealing surface of the solid particles, such as the sand will damage the hard ring surface on the grinding wheel, resulting in the sealing surface of the open or in the sealing surface generated between the crystals, and after re-grinding the graphite ring, the abrasive will be embedded in the surface of the graphite ring.

The failure of the rubber ring and use the usual high pressure so that the suppression of forming the O-ring failure, found that O-ring into a rectangle or ring harden, you need to adjust the amount of compression, or may have a fever.

So the use of temperature necessary to understand a synthetic rubber. Swelling of synthetic rubber ring is mostly caused due to chemical attack, they all have their own characteristics, such as fluorine rubber resistant to high temperature, ○-ring of ethylene, propylene used in the oil lubricant will swell, and ozone on NBR rubber erosion NBR products not installed in the motor, high temperature and chemical corrosion is usually caused by rubber products harden, crack the main reason.

Installation of rubber parts to be cut and surface nicks, but also common causes of seal failure. The signs of the old screws, the shaft keyway, spline shaft, sharp shaft shoulder can damage the rubber parts.