The key to the installation technology of the centrifug […]
The key to the installation technology of the centrifugal pump is to determine the installation height of the centrifugal pump, that is, the suction stroke. This height refers to the vertical distance from the water source to the centerline of the centrifugal pump impeller. It is not to be confused with the allowable vacuum height. The allowable vacuum height indicated on the pump product specification or on the nameplate refers to the vacuum value on the pump inlet section. Further, it was measured by a test under the conditions of 1 standard atmospheric pressure and a water temperature of 20 °C. It does not take into account the flow of water after the suction pipe is fitted.
The installation height of the pump should be the value of the remaining part that allows the suction vacuum height to be deducted from the loss of the suction pipe. It must overcome the actual terrain water absorption height. The installation height of the pump should not exceed the calculated value, otherwise the centrifugal pump will not be able to pump water. In addition, the magnitude of the influence calculation value is the resistance loss head of the water suction pipe. Therefore, it is advisable to use the shortest pipe arrangement and to install accessories such as elbows as little as possible. It is also conceivable to properly arrange pipes with larger diameters to reduce the flow rate inside the pipe.
It should be pointed out that when the elevation and water temperature of the installation place of the pipeline centrifugal pump are different from the test conditions, such as the local altitude above 300 meters or the water temperature of the pumped water exceeds 20 degrees Celsius, the calculated value should be corrected. That is, the atmospheric pressure at different elevations and the saturated vapor pressure above 20 degrees Celsius. However, when the water temperature is below 20 degrees Celsius, the saturated vapor pressure is negligible.
From the pipeline installation technology, the suction pipe requires strict sealing, and it cannot leak or leak water. Otherwise, the vacuum at the water inlet of the centrifugal pump will be destroyed, so that the water output of the centrifugal pump will be reduced, and even if it is serious, the water will not be pumped. Therefore, it is necessary to carefully do the interface work of the pipeline to ensure the construction quality of the pipeline connection.