Quick exhaust valves are special valves which are added to a cylinder to increase the cycle speed of pneumatic cylinder time during return of the piston. They are used in the inlet of a spring return or a double acting pneumatic cylinder.
Older models of pneumatic cylinders had no possibility of variation of release timings, since it solely depended on the rate at which the air can push back through the control command line to retract the piston in the cylinder. A faster return action of the cylinder can be achieved with the addition of Stainless Steel Quick exhaust valves which is in effect a 3 port tee valve fitting that is added to the inlet of the pneumatic cylinder command line.
The quick release valve is a 3 port valve fitted before the air supply entry to the cylinder. The free exhaust location marked in the drawing is always open to atmosphere. The control command or air supply source to the cylinder is from the bottom. The air supply or control command usually is from control valves. The port connection to the cylinder is at an angle to the other two inline ports. There is an oil resistant diaphragm of either VITON or Polyurethane chosen as per service medium and port size requirements. The diaphragm acts as the switching element in the valve.
When the air supply or control command is pressurised, air lifts up the diaphragm, closes free exhaust port and fills air into the cylinder. This action leads to movement of the piston in the cylinder (to the right in our case). It remains in this position as long as control command is pressurised.
When the cylinder needs to retract, air from control port is cut. This allows the diaphragm to return to rest position- thus blocking the control port. The air in the cylinder is open to the free exhaust port. Since the free exhaust is exposed to atmosphere, there is quick action during retraction of the cylinder- which effectively reduces cycle time.
Fractional range: 1/8” through 1/2” pipe thread
BSP as standard. BSPT, NPT and SAE threads also available on request.
Sealexcel is an established name across various industrial sectors owing to the dependability and durability of their pneumatic valve and fittings. Sealexcel’s robust Quick Exhaust valves are durable that adheres to high quality standards making it a leading Quick Exhaust Valve manufacturer.