Is it necessary to close the outlet valve when starting a centrifugal pump? Has there been any actual situation where the outlet valve was not closed and the motor worked fine?
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Is it necessary to close the outlet valve when starting a centrifugal pump? Has there been any actual situation where the outlet valve was not closed and the motor worked fine?
Theoretically, it is necessary to close the outlet valve; the current drawn when the pump starts is very high, which can easily damage the motor. The outlet valve should be gradually opened once the motor reaches its rated speed.
There’s no need to turn it off; for example, a self-priming pump requires the valve to remain open. If the motor burns out without the valve being closed, it means the wrong model was selected
The lubricating oil auxiliary pump of our engine unit starts directly; there is no outlet valve. However, it makes a very loud noise when starting
Does a self-priming pump need to have the valve open? The centrifugal self-priming pump can also be started in theory when the outlet valve is closed
Theoretically, the outlet valve should be closed before starting, but in actual production, it sometimes happens that the pump is started or stopped without closing the outlet valve, which is quite dangerous and can easily damage the motor.
There are operating procedures, right? . . It generally needs to be turned off. . .
Generally, there is such a requirement; everything has its special case! When starting a high-speed pump, the outlet should not be closed completely to prevent pressure buildup. There are also self-priming pumps with process requirements, whose outlets cannot be closed either.
Here, we usually apply a slightly higher rate for exports (10-15%).
I’ve tried running the pump without closing the outlet valve; the motor is fine, but if you keep doing this for a long time, the motor will definitely get damaged
The small pump should be fine; it’s hard to say about the large pump. Anyway, some of the operators in our workshop start the pumps without closing the outlet valves, but fortunately no problems occurred – what a relief!