Causes Of Seal Failure Of Stainless Steel Ball Valve

Recently, a customer reported that the 2 Piece Threaded Ball Valve seal failed. After our maintenance personnel visited the customer, they found that it was caused by the damage of the stainless steel ball valve bearing, but not all failures were caused by this reason. The reasons for the failure of the stainless steel ball valve seal are as follows.

1. Natural failure

Since the seal is always in the medium, the electric ball valve seal fails after the sealing element reaches its service life.

2. Large fluctuations in the pump inlet pressure may cause seal damage

When the pump inlet pressure is too small, the pressure in the pump chamber suddenly decreases, and the liquid in the sealing chamber flows back to the pump chamber, causing the sealing surface to dry rub. The sealing surface generates huge heat in a short period of time and cannot be taken away, which leads to the burning of the sealing surface and seal failure; when the pump inlet pressure is too high, as the sealing chamber pressure increases, when it exceeds the seal capacity, the electric ball valve seal fails.

3. Seal failure caused by insufficient seal flushing

The seal mainly blocks the seal chamber medium by forming a liquid film on the sealing surface. The role of the seal flushing liquid is mainly to take away the heat at the sealing surface.

When the seal flushing liquid is insufficient or there is huge heat in the sealing chamber, the seal surface will burn and the seal will fail.

Insufficient seal flushing may be caused by medium interruption in the pump cavity, sudden decrease in seal cavity pressure, or sudden damage to the seal effect ring.

4. Seal failure caused by bearing damage

After the bearing is damaged, the position of the rolling element changes, the vibration of the pump increases, and the electric ball valve seal fails.