A pneumatic proportional constant flow valve with mechanical feedback

To make the flow rate of a gas valve insensitive to changes in inlet pressure and to achieve proportional constant flow characteristics, a proportional constant flow valve is proposed, which is mechanically fed back by the pressure of the flowing gas itself. Using air as the source, the motion equation of the spool is established according to pneumatic theory. By means of the steady state equation, it is proved that the valve is insensitive to the change of inlet pressure compared with an ordinary proportional valve, and the optimization direction of the valve is analyzed. Based on Amesim software, the entire model of the pneumatic proportional constant flow valve is established, and the flow characteristic parameters of feedback holes with different diameters are obtained by numerical calculation. Subsequently, through overall simulation, we obtain the specific values of the optimization parameters. Finally, relevant experimental tests are conducted. The results show that the optimized proportional constant flow valve with mechanical feedback has a good proportional constant flow effect compared with the ordinary proportional flow valve.