High speed pneumatic valve common problems

pneumatic valve, usually by a pneumatic valve or in the downstream piping, pressure difference to produce high speed. And in the operation of the liquid itself generates turbulence and vibration, and high noise level in the operation of the gas. Speed is inversely proportional to the pressure loss and get, when logistics movement to the contraction section speed after slightly by the contraction section just reached maximum peak, pressure is at its lowest here.

the following general rules for speed: liquid generally should not exceed the ft/s ( 。 m/s） （ Or when air-pocket operation for ft/s or m/s) ； Gas should not exceed the speed of sound ( 马赫。 ） ； The mixture of gas and liquid ( For example, flash operation) Should not be more than the ft/s ( m/s） 。 This principle can change ( According to the size of pneumatic valves) , such as the small size of the pneumatic valve can normal higher processing speed, and large pneumatic valve can only deal with low velocity.

the temperature of the process liquid is close to saturation point, must be kept at the rate of less than or equal to the ft/s ( m/s） To avoid any fluid pressure drop below the vapor pressure and air pockets. The ft/s regulation is also applied to the operation of the wind hole, the higher the speed of the lead to the air hole damage downstream piping. Low speed will also reduce flash and wear problem.