The correct method for selecting chemical magnetic pumps

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The correct method for selecting chemical magnetic pumps: When choosing chemical magnetic pumps, it is necessary to take into account the nature of the enterprise’s production facilities, its own conditions, as well as the allowable constraints. The considerations mainly include medium flow rate, device head pressure, properties of the medium, pipeline layout, and operating conditions. I. Selection based on the physicochemical properties of the medium to be transported The physicochemical properties of the medium to be transported directly affect the performance, materials, and structure of the pump, and are one of the important factors to consider during selection. The physicochemical properties of a medium include: the name of the medium, its characteristics (such as corrosivity, abrasiveness, toxicity, etc.), the content and size of solid particles, density, viscosity, vapor pressure, etc. If necessary, the gas content in the medium should also be listed to indicate whether the medium is prone to crystallization or not. II. Selection based on process parameters Process parameters are the most important basis for selecting chemical magnetic pumps, and they should be determined carefully in light of the process flow and the range of operational variations. Parameters such as flow rate and head are among the key technical criteria for selecting a pump, as they directly affect the production capacity and transportation capacity of the entire system. 　(1). Flow rate: The flow rate refers to the amount of fluid that the pump is required to transport during the operation of the process unit. The process engineers should specify the normal minimum and maximum flow rates. Pump data sheets usually only provide the normal flow rate and the rated flow rate. When selecting a chemical magnetic pump, the rated flow rate should be no less than the maximum flow rate of the installation, or it should be 1.1 to 1.15 times the normal flow rate. 　(2). Head: Refers to the head value required by the process unit, also known as the calculated head. It is generally required that the rated head of the pump be 1.05 to 1.1 times the head required by the installation. 　(3). Inlet pressure and outlet pressure: The inlet and outlet pressures refer to the pressures at the flanges at the pump’s inlet and outlet. The levels of inlet and outlet pressure affect the pressure resistance requirements for the housing and shaft seal (sealing sleeve). 　(4). Temperature: Refers to the temperature of the medium at the pump’s inlet; generally, the normal, minimum, and maximum temperatures of the medium entering the magnetic pump should be specified. 　(5). The device’s net positive suction head available, NPSHa, is also known as the effective net positive suction head. 　(6). Operation mode: The operation mode is divided into continuous operation and intermittent operation. III. Selection based on the on-site conditions of chemical magnetic pumps The on-site conditions for chemical magnetic pumps include: (1) Installation location (indoor, outdoor, high altitude, seaside). 　(2). Ambient temperature. 　(3). Relative humidity. 　(4). Atmospheric pressure. (5). Atmospheric corrosion condition. 　(6). Classification levels of hazardous areas. IV. Selection based on the system’s piping layout conditions The system’s piping layout conditions refer to various parameters such as the height, distance, and direction of liquid flow, the lowest liquid level on the suction side, the highest liquid level on the discharge side, as well as details regarding pipe specifications, their lengths, materials, and the specifications and quantities of pipe fittings. These details are necessary for calculating the system’s head pressure and verifying the net positive suction head. V. Selection based on operating conditions There are many factors related to operating conditions, such as the saturated vapor pressure of the medium (liquid) under operation, the pressure on the suction side (absolute), the pressure in the container on the discharge side, altitude, ambient temperature, whether the operation is intermittent or continuous, and whether the pump’s location is fixed or movable. VI. For pumps with a power output of less than 10 KW, using chemical magnetic pumps can ensure optimal performance.