What To Do If The Centrifugal Pump Surges

Sanitary Centrifugal Pump surge Cause Analysis
1. The automatic exhaust valve of the water pump fails to exhaust the air in the pump in time;

2. The inlet flow channel of the water pump is too small, resulting in excessive inlet flow velocity of the water pump, causing vortex phenomenon at the inlet of the water pump;

3. There is a local excessive roughness at the inlet of the water pump impeller;

4. There are irregular and movable debris at the inlet pipe of the water pump, and the inlet cross section changes irregularly, resulting in excessive inlet flow velocity of the water pump, causing cavitation of the water pump;

5. The sealing of the joint of the outlet pipe of the water pump is not good, resulting in insufficient displacement of the exhaust valve of the water pump.

Surge will cause changes in pressure and flow in the entire system of the water pump. When cavitation occurs in the water pump, this phenomenon is called "cavitation surge". Even if the head and flow curves have a negative slope, cavitation surge will occur. For example, when there is a hump in the performance curve of a low-speed centrifugal pump, surge may occur under unstable conditions.

Methods for eliminating surge in centrifugal pumps
1. Check whether the automatic exhaust valve of the water pump is flexible and reliable;

2. Solve the problem of vortex generated at the inlet of the water pump due to small inlet flow of the water pump and excessive inlet flow rate;

3. Check whether the impeller and casing of the water pump are damaged;

4. Check whether there are movable foreign objects at and near the inlet of the water pump;

5. Check whether there is leakage at the joint of the outlet pipe of the water pump;

6. When starting the water pump, ensure the liquid level at the inlet of the water pump;

7. When selecting the hump curve, the water pump pipeline plan should be fully considered to make the working point of the water pump equipment fall in the stable operation area. It is recommended that the water pump should not work in the unstable small flow area.

8. The water pump flow regulating valve should be installed between the water pump and the air tank, not behind them, or the static head of the water pump cannot exceed the dead head of the pump.

Safety precautions for eliminating centrifugal pump surge
1. Take safety measures before overhauling the centrifugal pump;

2. During overhaul, turn off the pump power switch and take power outage measures;

3. Take safety precautions when inspecting the running pump.