Electric pneumatic control valve selection

Pneumatic control valve is mainly composed of body, sleeve, disc, stem and other parts. Sleeve and the disc drive with orifice by rotary disc in the seat to change flow area, regulate traffic. With ZKJ type or other type electric quarter-turn actuators can realize remote control and automatic control. Pneumatic - valve widely used in feed line to adjust flow. Can also be used in oil pipeline. Product selection points manner; Electric pneumatic control valve selection of main control parameters for: nominal pressure, nominal diameter, design allowed temperature range, flow coefficient, etc. 2. ; Open for traffic and high proportional relationship of rigorous situation, should choose special pneumatic control valve. Ball valve and butterfly valve general coarse adjustment can be chosen. 3. Valve sealing performance is one of the main indicators evaluation valve quality fit and unfit quality. Valve sealing performance mainly includes two aspects, namely, internal leakage and leakage. Leakage refers to between the seat and closed on the degree of sealing medium to achieve. Leakage is refers to the leak of stem packing place, in the mouth of the gasket leaking caused by casting defects of leaking, and the valve body. No leakage is allowed. 4. ; Pneumatic - valve ideal flow characteristic are quick opening, parabolic, linear, such as percentage of the four, to choose appropriate flow characteristics according to actual work flow characteristic of pneumatic control valve. ⒌; The selection of pneumatic control valve nominal diameter should be determined according to the required valve flow capacity. Pneumatic control valve nominal diameter should not be too big or too small. Increase the project cost is too big, and the valve is in low percentage range, accuracy is reduced, the control performance. Is too small, increase system resistance, can appear even open valve 100%, capacity requirements set by the system still cannot achieve.