Pump selection basis, should be based on the process flow, water supply and drainage requirements, from five aspects to be considered, both liquid delivery volume, device lift, liquid properties, piping layout and operating conditions.
1. Flow is one of the important performance data for pump selection. It is directly related to the production capacity and delivery capacity of the entire device. For example, in the process design of the design institute, the normal, minimum and maximum flow rates of the pump can be calculated. When the pump is selected, the maximum flow rate is taken as the basis and the normal flow rate is taken into consideration. When there is no maximum flow rate, it is usually possible to take 1.1 times of the normal flow rate as the maximum flow rate.
2. The required lift of the device system is another important performance data of the pump selection. Generally, it is necessary to use a 5% -10% margin to boost the selection.
3. Liquid properties, including names, physical properties, chemical properties, and other properties of the liquid medium, physical properties such as temperature c density d, viscosity u, solid particle diameter and gas content in the medium, etc. This involves the head of the system, effective cavitation Quantity calculation and type of suitable pump: The chemical nature, mainly refers to the chemical corrosivity and toxicity of the liquid medium, is the important basis for choosing the pump material and choosing which kind of shaft seal type.
4. The pipeline layout conditions of the installation system refer to the liquid-feeding distance of the liquid-feeding distance, the suction of the minimum liquid level, the maximum liquid level of the discharge side, and some data and pipe specifications, lengths, materials, pipe fittings specifications, and quantities. In order to carry out system head calculations and NPSH check.
5. There are many operating conditions, such as the operation of the liquid T saturated steam power P, suction side pressure PS (absolute), discharge side container pressure PZ, altitude, ambient temperature operation is gap or continuous, the pump position is fixed or Removable.