Mechanical Seal Failure Analysis

1, mechanical seals gears slipping. Some driving seat top wire is fixed on the sleeve can still use this transmission mode at room temperature, the heat pump temperature and centrifugal force, the top wire skid, transmission failure.

2, the stationary ring and moving ring did not contact mechanical seal installation mistakes. Mosaic moving ring, tungsten carbide ring loose.

3, the signs of wear of the friction pair face is greater than the soft ring width to two sealing surface width of the friction pair are not equal. Under normal circumstances, hard sealing surface of a wide, soft surface is narrow. Mechanical seals running for some time, the hard sealing surface clear signs of friction, according to the width of the judgment of this trace the causes of mechanical seals.

Pump vibration, mechanical seal rotating ring operating radial and axial runout, the film thickness change, sometimes mechanical seal sealing surface is pushed, causing the leakage increases. Static ring heart. General rotary seals, stationary ring installed in the gland, the gland and seal chamber co-ordination of concentricity by the Mouth guarantee. Fact, the Mouth of the gap is often too large, the stationary ring subsidence, caused by different heart of the movement ring.

Static bellows seal, due to the weight of the stationary ring component contributed to the stationary ring sinking, but also created a static ring heart. In addition, the bearing housing with the gap is too large shaft bending and so make the friction traces too broad. Overcome these defects, the first to eliminate the vibration of the centrifugal pump to do balancing the rotor; are unlikely to cause vibration coupling; the concentricity of the calibration pump and motor; check the pump, the Mouth of the gap is too large; in static taken in the bellows in the bottom of the stationary ring and bearing to prevent sinking.

5, in the mechanical seal rotating ring-side surface of the friction traces are not continuous or partial contact, and sometimes the great circle or dot contacts, it is clearly the injustice caused by the moving torus. Method to solve the mechanical seal these defects is: Check the move, the flatness of the static ring does not meet the requirements to the ground, until qualified. In order to reduce the deformation of the sealing surface, the value of the interference of the static ring seal is not too much to avoid the stationary ring deformation, high temperature

Seal to take effective supplementary measures, such as washing, cooling, etc., to minimize the seal itself, the temperature difference.

6, the stationary ring Seals uneven, a phenomenon that continuous exposure to trace along the inside edge of the sealing surface, the so-called convergence gap: seal dismantling often can not find other signs of wear. Work is the leakage volume. Some people think that the friction traces of narrow seal area reduces the pressure increases, it seems that should not leak. The opposite is true, when the contact of the inner edge of the sealing gap is showing convergence shape, damage the sealing surface parallel to the liquid film greatly increased the pressure will push the sealing surface, the amount of leakage increases.

Stationary ring is not parallel to the second friction marks the outer edge of the sealing surface contact and friction traces of diameter greater than the inside diameter of the stationary ring sealing surface between the sealing surface of the horn was this gap shape of the liquid film pressure decreases, resulting in than the pressure increases, the increased wear and tear, and prone to the grooves, the leakage rate increases, and not work properly.