How to select the appropriate model and parameters for plunger pumps based on specific needs, which requires considering the following five aspects: body discharge volume, installation head, fluid properties, pipeline layout, and operating conditions. This relates to the entire unit's production and conveying capacity. The following criteria should be considered when choosing a pump:

1. Flow rate is one of the key performance data for selecting pumps. Based on high flow rates while considering normal flow rates, when there is no high flow rate, it is generally acceptable to take 1.1 times the normal flow rate as the high flow rate. Typically, the head required for selecting the pump model should be increased by 5% to 10% with a safety margin.

2. The required head for the installation system is another crucial performance data for selecting a pump. This includes the name of the liquid medium, its properties such as physical, chemical, and other characteristics. Physical properties involve temperature (°C), density (d), viscosity (μ), the diameter of solid particles in the medium, and the content of gases, all of which relate to the system's head, the calculation of effective NPSH, and the selection of the appropriate pump type. Chemical properties primarily refer to the corrosiveness and toxicity of the liquid medium, which are important for selecting pump materials and the type of shaft seal.

3. The piping layout conditions of the system refer to the liquid delivery height, distance, and direction. Data such as the high liquid level on the discharge side, along with pipeline specifications and lengths, documentation, fitting specifications, and quantities are provided to facilitate the calculation of system head and the verification of cavitation margin.