Industrial pump selection conditions:
1, the physical and chemical properties of the conveying medium: the physical and chemical properties of the conveying medium directly affect the performance, material and structure of the pump, which is an important factor to be considered when selecting the type. The physical and chemical properties of the medium include: medium name, medium characteristics (such as corrosion, abrasion, toxicity, etc.), solid particle content and particle size, density, viscosity, vaporization pressure, etc. If necessary, the gas content in the medium should also be listed, indicating whether the medium is easy to produce.
2. Process parameters:
Process parameters are the most important basis for gear oil pump selection and should be carefully determined according to process flow and operating range.
(1) Flow rate Q Flow rate refers to the medium quality required by the pump in the production of the process device. The process personnel should generally give the normal, minimum and maximum flow rate. Only normal and rated flow rates are usually given on the pump data sheet. When selecting the pump, the rated flow is required not less than the maximum flow of the device, or take the normal flow
1.1 times 1.15 times.
(2) Head H refers to the head value required by the process device, also known as the calculated head. The rated lift of centrifugal oil pump is generally required to be 1.05-1.1 times of the required lift of the device.
(3) the inlet pressure Ps and the outlet pressure Pd inlet and outlet pressure refers to the pressure at the inlet and outlet flange of the pump, and the shadow of the inlet and outlet pressure t affects the pressure resistance of the shell and the requirements of the shaft seal.
(4) Temperature refers to the temperature of the pump inlet medium, generally should be given in the process of the pump inlet medium normal, minimum and maximum temperature.
(5) Device NPS day A is also called effective NPSH, and its calculation method is described in Chapter 3 of Chapter 2.
(s) Operation state Operation state can be divided into continuous operation and intermittent operation.
3. Site conditions:
The site conditions include the installation position of the pump (indoor and outdoor stainless steel pump requirements are more strict under special circumstances), environmental temperature, relative humidity, atmospheric pressure, atmospheric corrosion and the classification of dangerous areas.
