Water pump is an important equipment for fluid transportation and lifting. How to choose a pump? In order to improve the service life of the pump, the selection basis should be taken into consideration in five aspects according to the process flow and the requirement of water supply and drainage, such as the quantity of liquid, the lift of the device, the nature of the liquid, the arrangement of the pipeline and the operating conditions. The following is the selection of water pumps for users.
1, traffic is one of the important performance data of pump selection. It directly relates to the production capacity and transmission capacity of the whole device. For example, in the process design of the Design Institute, we can calculate the normal, minimum and maximum flow of three pumps. When choosing a pump, it is based on the large Zui flow rate and takes account of the normal flow rate. When there is no Zui flow rate, it usually takes 1.1 times the normal flow rate as the Zui large flow rate.
2, the required lift of the installation system is another important performance data for pump selection. Generally, the head lift is selected by enlarging the 5% - 10% surplus.
3. Liquid properties, including liquid medium name, physical property, chemical property and other properties. Physical properties include temperature C density D, viscosity u, solid particle diameter and gas content in medium, which involve the system lift, effective cavitation allowance calculation and suitable pump type: chemical properties, mainly liquid medium. The Chemical Corrosiveness and toxicity is the important basis for selecting pump material and selecting the type of shaft seal.
4. The piping layout conditions of the device system refer to the direction of the high liquid delivery distance of the feed liquid, the Zui low level of the side, the high level of the discharge side, the length of the pipe, the length of the pipe, the specifications and the quantity of the pipe fittings, etc. so as to make the calculation of the combing lift and check the cavitation residual.
5, the operating conditions are a lot of content, such as liquid T saturated steam P, suction side pressure PS (absolute), discharge side vessel pressure PZ, altitude, environmental temperature operation is clearance or continuous, the position of the pump is fixed or removable.