The DHD9156 High Flow Valve is intended for applications requiring the moving of large amounts of air in short periods of time, automatically. The unit offers both pressure and vacuum relief at an opening point of 0.50 psi ± 0.25 psi in both directions. Rapid decompression, or explosive decompression, is becoming a more common requirement for airborne military packages. This requirement has presented a very difficult design challenge. One solution to this requirement has been the use of rupture disks which require replacement if used or if accidentally over-pressurized.
With a flow rate of up to 140 SCFM, the DHD9156 will provide for the rapid decompression needs of a 50 ft.³ container that experiences a loss of pressurization from 10.1 psia (altitude of 10,000 ft.), a typical cargo hold pressure, to 2.7 psia, the external ambient pressure at 40,000 ft., in a 15 second time period.
Airborne transport of large volume containers, even without a rapid decompression requirement, need to move large volumes of air to keep from exploding or imploding due to atmospheric pressure changes with altitude. SAE AS27166 recommends that valves should have a flow capacity of 12% of the container volume. Applied to the High Flow Valve, this means a container of over 1,100 ft.³ can be protected with a single valve.
The manual release button ensures easy entry into the enclosure when it is under vacuum conditions and safe opening when the container is pressurized. The attached retaining clip guarantees the button is only used when intended. The lanyard makes losing the retaining clip impossible. The valve is low profile, projecting only 1.25" from the container wall to the tip of the manual release button. Installation into container walls up to 1/2" thick is simple.
Unit of Measure