In daily use, we also need to take some measures to pre […]
In daily use, we also need to take some measures to prevent cavitation in stainless steel centrifugal pumps, including:
1. Appropriately increase the pump inlet diameter and impeller inlet diameter, reduce the liquid flow rate at the pump inlet, or directly use a double-suction impeller, because the double-suction impeller is equivalent to the inlet area of two single-suction impellers, and the inlet flow rate can be reduced by one time under the same flow conditions. .
2. Thin the back of the blade head to improve the ejection of the blade entrance and reduce NPSHr. Or install an inducer to increase a certain pressure energy before the liquid enters the impeller.
3. When designing the piping system, the suction height of the pump should be as low as possible. If conditions permit, use reverse irrigation. When piping, appropriately shorten the length of the suction pipe, increase the diameter of the suction pipe, and minimize the number of unnecessary valves and elbows in the suction path to reduce the pipeline loss of the suction pipe.
4. The pump works in a state close to cavitation. For example, the use of dense anti-cavitation materials (copper alloy, stainless steel, etc.) to make the pump impeller can extend the life of the impeller. For example, the impeller welded by the rolled steel plate has stronger cavitation resistance than the cast impeller. The impeller can also be coated with non-metallic coating using epoxy resin, nylon, polyurethane, etc.
5. When selecting the stainless steel centrifugal pump, when the cavitation allowance of the device is low or the medium is easy to vaporize, the pump should be as low as possible.
6. During the operation of the stainless steel centrifugal pump, the outlet valve of the pump should be used to control the flow in a reasonable range. Cavitation is prone to occur when the pump is running with a large flow. During operation, the suction line valve is not allowed to adjust the flow.