The key to the installation of a centrifugal pump is to determine the pump installation height. This height refers to the vertical distance from the water source to the centerline of the pump impeller. It is not to be confused with the allowable vacuum height. The allowable vacuum height indicated on the pump nameplate or product manual refers to the vacuum value on the pump inlet section. It was measured at 1 standard atmospheric pressure and at a water temperature of 20 degrees Celsius. It does not consider the flow of water after the suction pipe is matched. 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 pump will not be able to pump water. In addition, the magnitude of the influence calculation value is the resistance loss head of the 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 equip the pipe with a larger diameter to reduce the flow rate inside the pipe.
It should be noted that when the elevation and water temperature of the pump installation location 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 altitude 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 pump will be destroyed, so that the water output of the 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.
