The causes that lead to the failure of sealing of valves
The causes that lead to the failure of sealing of sanitary valves include the following:
1. Natural failure
As the seal is always in the medium, the valve sealing will fail after the sealing element reaches its service life.
2. The big pressure fluctuations at the pump inlet may cause damage of the sealing
When the pressure at the pump inlet is too small, the pressure in the pump cavity suddenly drops and the liquid in the sealed chamber flows back to the pump cavity, resulting in the sealing surface dry friction. The huge amount of heat produced in a short period of time in the sealing surface can’t be taken away, resulting in sealing surface burnout and sealing failure. When the pressure at the pump inlet is too big, as the pressure in the pump cavity increases to the point where the limit the sealing can bear is exceeded, the valve sealing fails.
3. The sealing failure caused by inadequate sealing flushing
Sealing is achieved mainly by the blocking of the medium in the pump cavity by the liquid film formed on the sealing surface. The role of the flushing liquid is to take away the heat on the sealing surface. When the flushing fluid is not sufficient or there is a huge amount of heat inside the sealing cavity, there’ll be a sealing surface burnout and sealing failure. Cut-off of the medium in the pump cavity, sudden drop in pressure in the sealing chamber, damage of the sealing ring can all result in inadequate sealing flushing.
4. The sealing failure caused by damaged bearing
A damaged bearing causes the change of position of the rolling body, with the vibration of the pump increasing, leading to valve sealing failure.