隔膜泵在过程控制中的作用是接受调节器或计算机的控制信号，改变被调介质的流量，使被调参数维持在所要求的范围内，从而达到生产过程的自动化。如果把自动调节系统与人工调节过程相比较，检测单元是人的眼睛，调节控制单元是人的大脑，那么执行单元—隔膜泵就是人的手和脚。要实现对工艺过程某一参数如温度、压力、流量、液位等的调节控制，都离不开隔膜泵。因此正确选择隔膜泵在过程自动化中具有重要意义。 Diaphragm pump role in the process control is to accept the regulator control signal, or computer change modulated medium flow, make the modulated maintain within the scope of the required parameters, so as to achieve the automation of production process. If the automatic control system compared with manual adjustment process, the detection unit are the eyes of the people, to adjust the control unit is the brain of a person, then execute unit - diaphragm pump is one of the hands and feet. In order to realize the control of temperature, pressure, flow, liquid level, etc., the diaphragm pump is dependent on the process. It is therefore important to choose the diaphragm pump correctly in process automation. 1.隔膜泵的组成与分类 Composition and classification of diaphragm pumps 隔膜泵又称控制泵，是执行器的主要类型，通过接受调节控制单元输出的控制信号，借助动力操作去改变流体流量。隔膜泵一般由执行机构和阀门组成。如果按其所配执行机构使用的动力，隔膜泵可以分为气动、电动、液动三种，即以压缩空气为动力源的气动隔膜泵，以电为动力源的电动隔膜泵，以液体介质(如油等)压力为动力的电液动隔膜泵，另外，按其功能和特性分，还有电磁阀、电子式、智能式、现场总线型隔膜泵等。隔膜泵的产品类型很多，结构也多种多样，而且还在不断更新和变化。一般来说阀是通用的，既可以与气动执行机构匹配，也可以与电动执行机构或其他执行机构匹配。 Pump, diaphragm pump, also known as control is the main type of actuator, by accepting conditioning control unit of the output control signal, from engine operation to change fluid flow. Diaphragm pumps are usually composed of actuators and valves. If by their ticket enforcement agencies use the power, the diaphragm pump can be divided into pneumatic, electrical, fluid movement three, namely to compressed air to power sources pneumatic diaphragm pump, based on electric power electric diaphragm pump, as a liquid medium (such as oil) pressure as the power of electric hydraulic diaphragm pump, in addition, according to its function and feature points, and electromagnetic valves, electronic style, smart, the total linear diaphragm pump, etc. The diaphragm pump has many types of products and has a variety of structures, and is constantly updating and changing. Generally speaking, the valve is generic and can be matched with the pneumatic actuator, or with an electric actuator or other actuator. 2.隔膜泵类型的选择 Choice of diaphragm pump type 2.1隔膜泵的阀体类型 Body type of diaphragm pump 选择阀体的选择是隔膜泵选择中最重要的环节。隔膜泵阀体种类很多，常用的有直通单座、直通双座、角形、隔膜、小流量、三通、偏心旋转、蝶形、套筒式、球形等10种。在选择阀门之前，要对控制过程的介质、工艺条件和参数进行细心的分析，收集足够的数据，了解系统对隔膜泵的要求，根据所收集的数据来确定所要使用的阀门类型。在具体选择时，可从以下几方面考虑: Selecting the body is the most important part of the diaphragm pump selection. Diaphragm pump valve body is a lot of more phyletic, the commonly used is through single-seat, pass-through two-seater, angular, diaphragm, small flow rate, tee, eccentric rotating, butterfly, sleeve, spherical, etc. 10. Before you choose the valve, the control process of medium, the careful analysis of process conditions and parameters, collect enough data, understand the requirement of system of diaphragm pump, according to the collected data to determine the valve type to be used. When choosing a specific choice, consider the following: (1)阀芯形状结构主要根据所选择的流量特性和不平衡力等因素考虑。 (1) the shape structure of the valve is based on factors such as flow characteristics and unbalanced force. (2)耐磨损性当流体介质是含有高浓度磨损性颗粒的悬浮液时，阀芯、阀座接合面每一次关闭都会受到严重摩擦。因此阀门的流路要光滑，阀的内部材料要坚硬。 (2) when the fluid medium is a suspension fluid containing high levels of abrasion particles, the valve core and the seating surface of the valve are severely rubbed against each shutdown. So the valve's flow is smooth and the inside of the valve is hard.