An inflatable aircraft evacuation slide system includes a primary valve, a
bust disk and a valve leakage trap operatively disposed between the
primary valve and the burst disk. The valve leakage trap comprises a
small exhaust vent opening into a flow restriction orifice in the gas
path between the primary valve and the burst disk. In operation, when the
aircraft emergency exit is opened in the armed condition, the primary
valve opens and pressurizes the chamber until the burst disk ruptures
allowing inflation gases to pass through the flow restriction orifice to
inflate the inflatable evacuation slide. Because there is a substantial
pressure drop across the flow restriction orifice, the presence of the
valve leakage safety vent in the orifice does not result in significant
loss of inflation gas needed for inflating the inflatable evacuation
slide. In the event of leakage past the primary valve, however, the valve
leakage trap safely vents the leakage pressure to the atmosphere.