Pneumatic small flow control valve is small in size, light in weight and high in performance. It is used for precise control of small flow, such as precise chemical industry, scientific research institutes for precise micro-control of flow and pressure, etc. Pneumatic small flow control valve improves the sealing performance through structural improvement, thus improving the accuracy of flow control.
Pneumatic small flow control valve has long service life and high regulating precision. The design of special valve internals ensures that the small spool is not easy to break. When regulating unclean medium, in view of the small throttle gap, the blockage phenomenon is prevented by the design. The spool is not easy to block. It is suitable for small flow of liquid, steam and other media. Adjustment occasions.
The working principle of the pneumatic small flow regulating valve is:
Pneumatic small flow control valve changes valve opening through 4-20mA signal, so as to change the closure area of the control valve, to achieve the purpose of flow change! uuuuuuuuuuu The compressed air is used as the power to control the pressure of the air source through the electric valve positioner. The air acts on the rubber diaphragm of the control valve. The contraction and expansion of the diaphragm drive the stem up and down again, so as to achieve the purpose of controlling the medium. The regulator (DCS signal) converts the electric signal to the gas signal through the electric valve positioner and acts on the diaphragm of the regulating valve. The diaphragm compression spring drives the action of the regulating valve spool to control the opening of the valve, thus realizing the adjustment of the medium to be regulated. According to the technological requirements, the regulating valve is divided into air-opening valve (fault-closing) and air-closing valve (fault-opening). ).
Pneumatic small flow control valve has an effective and sufficient top guidance system to overcome the vibration of small opening. Its effective service life is longer. The choice of smaller flow coefficient increases the use of the valve. Its Kv value is smaller. It is mostly used for precise control of small flow, such as fine chemical industry, food additives, medicine, electronics and other industries.