Centrifugal pump coupling
一 coupling mode
1 parallel operation
After two identical model pump paralleled, its characteristic curve can be used single pump characteristic curve synthesis. When pipeline characteristic curve unchanged, flow increases after the parallel, but less than two single pump flow sum, namely Q parallel < 2Q single, while H single > H single.
2 serial operation
After two identical model pump series, its characteristic curve can also be used single pump characteristic curve synthesis. When pipeline characteristic curve unchanged, the series pressure head increases, but also less than two single pump pressure head sum, namely H serial < 2H single, and Q serial> Q single.
3 compound mode selection
If the pipe two ends () value is greater than pump can provide maximum pressure head, then must use series operation.
To low resistance type pipe (namely pipeline characteristic curve quite gentle), parallel pump flow and pressure head are larger than series pump.
To high impedance type pipe (namely pipeline characteristic curve compared steep), series pump flow and pressure head are larger than parallel pump.
二 installation and operation
Centrifugal pump installing height should be below the allowed installation height (namely calculation of installation height), lest produce cavitation phenomenon. In order to reduce the fluid resistance, inhaled pipe diameter should be not less than pump suction diameter, the suction pipe should be short and straight, without valve, but when pump suction above liquid surface should add stop inverse bottom valve.
Before centrifugal pump start-up, shall filling liquid, lest produce gas earthbind phenomenon; closing outlet valve in order to decrease the start-up power.
Before stopping the centrifugal pump, first need to close outlet valve.
when centrifugal pump operates, should be regularly check the shaft seal leakage or not, bearings, stuffing box etc, heating condition, bearing should pay attention to lubrication
