Time：2026-10-09 10:15:22 Browser 14 Origin：本站
The valve body of the pneumatic-electric high-precision control valve is provided with a valve chamber where a valve seat is fitted. A valve plug is mounted on the valve seat. The bottom of the valve plug is machined with a control orifice. A radial through-hole is arranged circumferentially in the middle of the valve plug, and each radial through-hole communicates with the valve chamber above the valve seat. The valve plug adopts a piston-needle type structure. The lower end of the needle-type valve plug is coaxial with the control orifice. A sealing plate is arranged in the middle of the valve plug to form a sealing interface with the inner wall of the sleeve, and the upper end of the valve plug extends through the valve bonnet.
During operation of the pneumatic high-precision control valve, the pneumatic actuator drives the valve plug upward. The positioner receives a 4–20 mA signal to adjust the valve opening. A gap forms between the lower end of the needle-type valve plug and the control orifice. Fluid flows from the valve chamber below the seat, passing sequentially through the control orifice, the flow passage in the guide plate and the radial through-hole in the middle of the valve plug, and enters the valve chamber above the valve seat. Precise regulation is achieved by varying the covered area of the radial through-hole via the sealing plate on the valve plug.
SEVICON pneumatic high-precision control valves realize multi-stage pressure reduction and flow throttling. Pressure is reduced for the first time through a constricted bell mouth and further reduced via throttling at the valve seat. They are suitable for various high-pressure and low-flow control applications.
High-Precision Control Valve Design
The low-flow high-precision control valve independently developed by SEVICON consists of a valve body, valve seat, valve bonnet, throttling plate, valve stem, oil-free bushing, packing and sealing rings. The seat seal is arranged inside the valve body, and the throttling plate is mounted at the lower end of the valve seat. The valve stem passes through the valve bonnet and connects to the valve plug. The oil-free bushing is installed on the inner side of the valve bonnet and closely fits the valve stem. The packing is fitted at the upper part inside the valve bonnet, and the sealing gasket is placed at the joint between the valve body and the valve seat. This design reduces leakage and improves the control precision of the valve. SEVICON pneumatic high-precision control valves overcome the technical drawbacks of poor sealing performance and low control accuracy found in conventional flow control valves.
It transmits accurate fully-open and fully-closed valve position feedback signals to the on-site DCS safety barrier.
SEVICON high-precision pneumatic control valves have been successfully applied in specialty gas supply and recovery systems, enabling precise control of on-site gas flow and meeting customers’ diverse requirements for specialty gases.
High-precision control valves are available in two types upon customer request: pneumatic high-precision control valves and electric high-precision control valves. The valve bodies of both types are precision-machined with CNC technology and adopt the structural design described above. Actuator options include pneumatic diaphragm actuators and electronic actuators. Depending on precision requirements, accessories such as Siemens positioners and imported electric actuators can be equipped. The whole system features high accuracy and low leakage rate, and can operate safely and stably with various gas mixtures and liquid media.
Should you require information on pricing and technical specifications of our high-precision control valves, please contact our team. We will support model selection and provide a suitable control solution. We look forward to cooperating with you.
