Installed centrifugal pump to determine the height of the pump is the focus
The key to the installation technology of centrifugal pump is to determine the installation height of the pump. This height refers to the vertical distance from the water surface to the center line of the impeller of the pump, which cannot 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 water inlet section of the pump, and it is measured under 1 standard atmosphere pressure; the water temperature is 20 degrees Celsius, and the test is conducted. It does not take into account the water flow condition after the suction pipeline. The installation height of the pump should be allowed to suck up the vacuum height after deducting the loss of head of the suction pipe, the remaining part of the value, which should overcome the actual terrain suction height. The installation height of water pump cannot exceed the calculated value, otherwise, the pump will not be able to pump water. In addition, the size of the influence of the calculated value is the resistance of the suction pipe loss head, therefore, it is appropriate to use the shortest pipeline arrangement, and as little as possible to install elbows and other accessories, but also consider the appropriate with some large caliber of water pipe, in order to reduce the flow rate in the pipe.
It should be noted that the pump installation site elevation and water temperature is different from the test conditions, such as the local altitude of 300 meters above sea level or pumped water temperature exceeds 20 degrees Celsius, the calculated value should be amended. That is, the atmospheric pressure at different elevations and the saturated vapor pressure when the water temperature is higher than 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 pipeline requires strict sealing, can not leak air and water, otherwise it will destroy the vacuum at the water inlet of the pump, so that the pump water output is reduced, and in serious cases even can not pump water to. Therefore, the interface of the pipeline should be done carefully to ensure the construction quality of the pipeline connection.