Is It Necessary To Close The Outlet Valve Of The Centrifugal Water Pump When It Is Started?

Is It Necessary To Close The Outlet Valve Of The Centrifugal Water Pump When It Is Started?

When the centrifugal water pump is started, there is still no water in the outlet pipe of the pump, so there is no pipe resistance and resistance to lifting height. After the centrifugal pump is started, the head of the centrifugal pump is very low and the flow rate is large. At this time, the pump motor (shaft Power) output is very large (according to the pump performance curve), it is easy to overload, it will damage the pump motor and circuit, so the outlet valve must be closed when starting to make the pump run normally.

If an axial flow pump is used, the situation is the opposite. It must be started by opening the valve. At this time, the power of the motor is the smallest for a short period of time because there is no resistance, and it will run at a high flow rate. Pump vibration, noise, and even motor overload operation often occur. Burn the motor. Closing the outlet valve is equivalent to artificially setting the pipe resistance pressure. After the pump runs normally, start the valve slowly to allow the pump to gradually work normally along its performance curve.

Two points must be guaranteed before the centrifugal pump is started:

1. Fill the pump casing with water in order to form a vacuum;

2. The gate valve on the outlet pipe must be closed, so that the pump does not form a flow, which can reduce the motor starting current, which is beneficial to the smooth start of the pump. The gate valve should be opened slowly in time as the pump starts smoothly.

The centrifugal pump relies on the centrifugal force of the impeller to form the vacuum suction to lift the water. Therefore, when the centrifugal pump is started, the outlet valve must be closed and water is filled. The water level is above the impeller and the air in the centrifugal pump can be started. After starting, a vacuum is formed around the impeller to suck up the water. It can automatically open and lift the water. Therefore, the outlet valve must be closed first.


Post time: Jan-28-2021

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