The main reason for the failure of mechanical seals in stainless steel gear pumps

The main reasons for the failure of mechanical seals produced by stainless steel gear pumps are:

1 The liquid medium has poor lubricity, and the operating pressure is overloaded, and the tracking surfaces of the two sealing surfaces are not synchronized. For example, the high speed pump speed is 20445r/min, the sealing surface center diameter is 7cm, and the line speed is up to 75m/s after the pump is running. When there is a sealing surface lag, the rotation cannot be tracked, and the sealing surface is damaged by the instantaneous high temperature. Frequent occurrence of hydraulic characteristics of the liquid medium causes the pump unit to vibrate, causing the sealing surface to be misaligned and fail. The liquid medium corrodes the sealing element, stress concentration, soft and hard material coordination, erosion, auxiliary sealing 0-ring, V-ring, concave ring is incompatible with liquid medium, deformation, etc. will cause mechanical seal surface damage failure, so The damage form should be comprehensively analyzed to find out the root cause and ensure that the mechanical seal runs for a long time.

2 The liquid medium vaporizes and expands, so that the two end faces are separated by the vaporization expansion force. When the two sealing faces are pressed together, the lubricating film is broken and the surface of the end face is overheated. The pump transmission parts have poor coaxiality. After the pump is turned on, the end face is shaken once every revolution, and the running track of the moving ring is not concentric, causing the end face to vaporize and overheat and wear.

3 When the sealing surface is too large, the flushing fluid can't take away the heat generated by the friction pair; the flushing liquid leaks away from the gap of the sealing surface, causing the end surface to overheat and damage.

4 The seal flushing liquid orifice plate or filter is clogged, resulting in insufficient water and invalidation of the machine seal.