Steps for selecting a pipeline pump

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Relatively speaking, pipeline pumps do not have high requirements regarding flow rate or the medium to be transported; therefore, the selection of a pipeline pump is mainly based on appropriate flow rate and head. The criteria for selecting pipeline pumps should be determined based on the process flow and water supply/distribution requirements, taking into consideration five aspects: liquid flow rate, head capacity, properties of the liquid, piping layout, and operating conditions. It is considered from five main aspects: liquid flow rate, pump head, properties of the liquid, pipeline layout, and operating conditions. I. First, list the basic data: 1. Properties of the medium: name of the medium, specific gravity, viscosity, corrosivity, toxicity, etc. 　　 2. The diameter and concentration of solid particles contained in the medium. 　　 3. Medium temperature: (°C) 4. Required flow rate: For general industrial pumps, the leakage in the piping system can be ignored in the process flow; however, the impact of process changes on the flow rate must be taken into account. If agricultural pumps are used for water conveyance through open channels, leakage and evaporation rates must also be taken into account. 5. Pressure: pressure in the water intake tank, pressure in the water discharge tank, and pressure difference in the piping system (head loss). 　　 6. Pipeline system data (pipe diameter, length, types and quantities of pipeline accessories, geometric parameters from the suction tank to the pressure tank, etc.). 　　 If necessary, the device characteristic curve should also be prepared. 　 　 Secondly, when designing and arranging pipes, the following points should be taken into account: A. Choose the pipe diameter appropriately. A larger pipe diameter results in a lower flow velocity at the same flow rate, thereby reducing frictional losses; however, it increases costs. A smaller pipe diameter leads to a sharp increase in frictional losses, which in turn requires a pump with higher head pressure, greater power consumption, and higher costs as well as operating expenses. Therefore, a comprehensive consideration from both technical and economic perspectives is necessary. 　　 B. The discharge pipe and its fittings should take into account the maximum pressure they can withstand. 　　 C. The piping layout should be arranged as straight as possible; accessories within the pipes should be minimized, and the length of the pipes should also be reduced as much as feasible. When bends are necessary, the radius of curvature of those bends should be 3 to 5 times the diameter of the pipes, with the angle being as large as possible, ideally greater than 90°. 　　 D. A valve (such as a ball valve or globe valve) and a check valve must be installed on the discharge side of the pump. Valves are used to adjust the operating point of the pump, while check valves prevent the pump from rotating in reverse when fluid flows backward, thus protecting the pump from water hammer effects. (When the liquid flows back, a huge reverse pressure is generated, which can damage the pump.) II. Determining the flow rate and head of pipeline pumps – Flow rate determination The flow rate is one of the important performance parameters in selecting pipeline pumps; it is directly related to the production capacity and transportation capability of the entire system. As in the hypothetical calculations for the plant, it is possible to determine the normal, minimum, and maximum flow rates of the pump. When selecting a pump, the maximum flow rate is taken as the basis, while also considering the abnormal flow rate; when the maximum flow rate is not available, 11 times the abnormal flow rate can be used as the maximum flow rate. 　 a. If the minimum, normal, and maximum flow rates are specified in the production process, the maximum flow rate should be taken into account. 　　 b. If only the normal flow rate is specified in the production process, a certain margin should be considered. 　　 　　For high-flow, low-head pumps with ns>100, the flow margin is set at 5%, for ns