Address:H7/1-2, Qingyang Industrial Headquarter Base, No. 1 Chengfei Avenue, Qingyang District, Chengdu, Sichuan

Overseas Dept in Shenzhen:

Tel: 86-755-83234282


Skype: ellenhu.selectech


Address: E-605 Yuetong Building,MeiLong South Road, MinZhi,Longhua,ShenZhen , GuangDong,China,518131

Selection Guide

Guide for Selecting Micro Vacuum Pump, Micro Air Pump, and Micro Diaphragm Liquid Pump


    See the type selection list for general situation before type selection, and details are listed as follows.   

    After years of hard work, our current main stream products are of many series and specifications, applied to each field. It becomes difficult to select the most appropriate product with so many options.

    First we shall identify the purpose of the micro pump. We will discuss three applications of micro pump.

    I. Micro pump is used to export compressed air.

       Simply speaking, this is the case where micro pump is only used to pump up and inflate, and the pumping hole of the pump is basically out of service. This circumstance is simple. Various types are available by output pressure from high to low:FCY series, FQY series, FKY series and FNY series. Of course relevant technical parameters such as flow index should be considered.

    II. In following situations, WKY series (constant speed),WNY series (variable speed), WJY series (constant speed),WPY series (variable speed),and WUY series(variable speed) ,WAT series (Economical version is equipped with brush motor) and WAJ series (Economical version is equipped with brush motor) should be selected. WNY, WPY, and WUY can be electrically controlled with PWM for speed governing.

        1. Micro pump is required to pump air or vacuum, and sometimes there will be liquid water entering into the pump chamber.

        2. Micro pump is required to pump both air and water.

        3. Micro pump is used mainly to pump water, but it is not supposed to manually add some water for guiding. (Some water pumps need to manually add some water to drive away the air and to increase leak tightness, and in such a way to pump water at lower place or the pump cannot pump and even get damaged). The advantage of the above series starting with the letter W is they will pump vacuum when they didn’t contact water, and pump the water forcibly with vacuum, and then begin to pump water.

        4. Micro pump is used to pump water, but sometimes there may be no water to pump, and then the pump is in dry operation. Ordinary water pumps are not designed for dry operation which may be fatal. However, the above W series products are complex pump. They integrated the function of vacuum pump and water pump. And some people call them vacuum water pump. Thus, when there is no water, it will pump vacuum, and when there is water, it will pump water. No matter it pumps air or water; it is in normal operating status. It will not be damaged in “dry operation”.

    III. Micro pump is used to pump air.

        In this case, it is required to determine conditions of the exhaust side of the micro pump first.

        In practical applications, the exhaust situation faced by the micro vacuum pump (suction pump) is not the same: sometimes the exhaust is very smooth, straightly to the atmosphere; while other times there is large exhaust resistance, for example, there are valves, small bending, damping sensor, non-exclusive muffler in the way of exhaust pipe, and exhausting below the liquid level, gas discharged into closed or semi- airtight container. In modern design and manufacturing, the micro vacuum pumps are treated differently by different exhaust conditions. The parameter “Maximum Exhaust Resistance Allowed: Por” is used to calibrate the exhaust capacity of the pump, so we can determine the selection is appropriate or not with stringent technical method.

        For system with large exhaust resistance, the selection shall be made within the series starting from the letter F, including FCY series (constant speed), FQY series (constant speed),FKY series (constant speed), FNY series (constant speed).

        For system with less exhaust resistance: 1. Series with brushless motor:VLC series(variable speed), VLK series(variable speed), VKY series,VCY series, VAY series,VJY series,VQY series and VBY series(variable speed).
2. Series with brush motor:VAT series(Economical version) and VAJ series(Economical version).

        According to above steps, the range of selection of micro pump may be determined. The specific model may be decided according to the requirements of flow rate and vacuum degree from the series which can be selected. The products to be obsolete are not included here. It is not appropriate to be chosen. It is advised that redundancy shall be given to the parameters, especially that concerning the flow. After the pump is connected to the air path, the flow rate of the pump will be less than the nominal flow rate of the pump due to the pressure loss of the pipeline and valve which will weaken the flow. There are some other issues relevant to the selection which can be taken as a reference.

    1. Start with load.

       If there is a vacuum in the pumping hole or a pressure in the exhaust hole of the micro pump before starting, another parameter shall be considered: inlet maximum starting load Pis, and exhaust hole maximum starting load Pos. The typical application is to maintain vacuum or positive pressure in the vessel with the micro air pump, and when the vacuum or positive pressure in the vessel is lower than the set value, the pump needs to be powered on, and when the vacuum or positive pressure in the vessel is higher than the set value, the pump needs to be powered off. This performance has a high requirement to the technical level of the manufacturer. If this performance is required, it is recommended to contact the manufacturer for necessary technical support.

    2. The medium temperature of the micro pump.

       It is advised to select normal or high temperature type according to the temperature of the air or liquid going through the pump.

    3. The electromagnetic interference of the micro pump.

       If the micro pump is controlled by precise circuit, micro pump with brushless motor is preferred. If micro pump with brush motor is selected, it must be “low interference type” so as to ensure the stability of the system.

    4. Speed regulating performance, feedback signal, and self-protection.

       These functions shall be selected according to the specific needs. These functions are recommended for high-end applications or fields where high stability is required.

Chengdu Qihai Electromechanical Equipment Manufacturing Co., Ltd
成都气海机电制造有限公司 蜀ICP备12008449 成公网备字[200600057]号