The basic selection of gear pump Pump selection basis, should be based on process, water supply and drainage requirements, to be considered from five aspects, namely liquid delivery capacity, the device head, liquid properties, piping layout and operating conditions. 1, the flow rate is one of the important performance of the election pump data, which is directly related to the entire plant's production capacity and delivery capacity. Such as the design process can be calculated in the pump normal, minimum, maximum three kinds of flow. Select the pump, based on the maximum flow, take into account the normal flow, in the absence of the maximum flow, it is usually desirable 1.1 times the normal flow as the maximum flow. 2, the lift system required for installation of the pump is another important performance data, generally to enlarge the 5% -10% head lift to choose. 3, the liquid properties, including the name of the liquid medium, physical properties, chemical properties and other properties, the physical properties of the temperature c density d, viscosity u, medium particle diameter and gas content, etc., which involves the system lift, effective gas Erosion margin calculation and the type of suitable pump: Chemical nature, mainly refers to the liquid medium chemical corrosion and toxicity, is the selection of pump materials and choose an important basis for the type of shaft seal. 4, the installation of piping system conditions refers to the liquid from the height of the liquid into the liquid distance to the suction side such as the lowest level, the highest level of the discharge side of some data and pipe specifications and length, material, pipe specifications, the number , Etc., in order to carry out the Department of combing head calculation and NPSH check. 5, the operating conditions are many, such as the operation of the liquid T saturated steam P, suction side pressure PS (absolute), the discharge side of the tank pressure PZ, altitude, ambient temperature operation is gap or continuous, the pump position is fixed Or removable. The specific operation of pump selection according to pump selection principle and selection of basic conditions, the specific operation is as follows: 1, according to the device layout, topography, water conditions, operating conditions, to determine the choice of horizontal, vertical and other types (pipe, Submersible, submerged, non-clogging, self-priming, gear-type, etc.) pumps. 2, according to the nature of the liquid medium to determine the water pump, hot water pump or pump, chemical pump or corrosion-resistant pump or impurity pump, or non-clogging pump. Pumps installed in the explosive area should be based on the explosion area level, using the appropriate explosion-proof motor. 3, gear pump according to the size of the flow, to determine whether the suction pump or dual suction pump menu; according to the level of the head, single-stage pump or multi-stage pump, high speed pump or low speed pump (air conditioning pump) , Such as single-stage pump and multi-stage pump can also be used when the first choice of single-stage pump.
