Pneumatic valve info

Pneumatic valves are driven by compressed air valves. Pneumatic valve procurement only clear specifications, categories, pressure to meet the procurement requirements of the practice, can be used to control air, water, steam, corrosive media, mud, oil, liquid metal and radioactive media and other types of fluid flow. In the current market economy environment is not perfect. Because of the pneumatic valve manufacturers in order to product competition, each in the unified design of pneumatic valves under the concept of different innovation, the formation of their own enterprise standards and product personality. Therefore, in the pneumatic valve procurement more detailed technical requirements, and manufacturers to achieve consensus, as the pneumatic valve procurement contract accessories is very necessary. This class of valves should generally be installed horizontally in the pipeline. The working principle of Using compressed air driven actuators in combination of multiple sets of pneumatic piston movement and force to beam and the characteristics of the curve track, drive tubular spindle rotation, compressed air disks to each cylinder, changed the direction of gas in and out of position to change the direction of spindle rotation, according to the requirement of the load (valve) the required rotation torque, adjustable cylinder combination number, drives the work load (valve). Two five-way solenoid valve which is equipped with double-acting pneumatic actuators, two is two position control, on-off, there are five tunnel ventilation, 45 is one connected with gas source, two external and double-acting cylinder chamber in and out of the port connection, two with the internal chamber in and out of the port in succession, you may refer to the working principle of concrete working principle of the double-acting pneumatic actuators. Due to more and more control methods and means, in the actual industrial production and industrial control, there are also many methods to control pneumatic actuators, commonly used as the following. Intelligent display instrument Intelligent display is used to monitor the valve working condition and control the valve opening work of the instrument, it through two lines of position sensor to monitor the working state of the valve, the valve is in open valve or valve state, through programming records of valve switch Numbers, there are two road and valve opening and the corresponding 4 ~ 20 ma output and bipedal normally open normally closed contacts. Through these output signals, control valve switch action. Control system PLC in the control system is more and more widely used, because this scheme is in OMRON PLC above the development, so OMRON PLC to introduce. Hardware :1 computer, 1 SET of PLC(including CPU, I/O module, ID212, OC224, AD003 module), 2 relays, 2 solenoid valves, 1 pneumatic valve actuator. General requirements 1, the production of pneumatic valve specifications and categories, should meet the requirements of the pipeline design documents. Pneumatic valve Pneumatic valve 2, pneumatic valve model should indicate the national standard number requirements. If the enterprise standard, should indicate the model related specification. 3, pneumatic valve working pressure, the requirement of ≥ pipeline working pressure, on the premise of not affecting the price, the valve can bear pressure should be greater than the actual pipeline working pressure; Under the closed condition of pneumatic valve, either side should be able to bear 1.1 times of the working pressure of the valve without leakage; When the valve is open, the body shall be able to withstand twice the valve pressure. 4, pneumatic valve manufacturing standards, should be explained according to the national standard number, if the enterprise standards, the purchase contract should be attached to the enterprise documents. Definition of folding parameters Nominal diameter is the largest outside diameter in the world, and we have to make up the nominal DN size of pipes and fittings. Pipe and pipe fittings with the same nominal diameter can be connected with each other and have interchangeability. It is not the actual pipe outside diameter or inside diameter, although its value is close to or equal to the pipe inside diameter. For example, welded steel tubes can be divided into thin-wall steel tubes, ordinary steel tubes and thickened steel tubes according to their thickness. The nominal diameter is not the outside diameter nor the inside diameter, but a nominal size similar to the ordinary steel tube inside diameter. Each nominal diameter corresponds to an outer diameter whose inner diameter varies with thickness. Nominal diameter can be expressed in metric mm or in. Pipe fittings are also indicated by nominal diameter, the same meaning as the slit pipe. Nominal pressure: maximum allowable working pressure for use at a given temperature. For the control valve of carbon steel body, refers to the maximum allowable working pressure when applied below 300℃; For cast iron valve body, refers to the maximum allowable working pressure when applied below 120℃; The control valve for the stainless steel body refers to the maximum allowable working pressure when applied below 250℃. When the operating temperature increases, the pressure of the valve body will be reduced. For example, carbon steel control valves at nominal pressure of 6.4MPa(PN64) have a pressure tolerance of 5.2MPa at 300 ° C, 4.1MPa at 400 ° C, and 2.9MPa at 450 ° C. Therefore, the control valve nominal pressure to determine not only according to the maximum working pressure, but also according to the maximum working temperature and material characteristics, not only to meet the nominal pressure is greater than the working pressure.