Dump Valve, Gold Body 90554902 Optional Normally Closed Dump Valve, Silver Body Controlled Response Height Control Valve Dump Valves 90054007 Type CR - Controlled Response Height Control Valve 1/4" 90554114 Type CR - Controlled Response Height Control Valve No Fittings 90554183 Type CR - Controlled Response Height Control Valve 3/8"Sep 12, 2020 · Pressurization safety valves are used to prevent the over-pressurization of the aircraft cabin. They open at a preset differential pressure and allow air to flow out of the cabin, also act as a dump valve, allowing the crew to dump cabin air manually. On most aircraft, safety valves are set to open between 8 and 10 psid.
Apr 07, 2002 · During an RTLS abort, liquid oxygen initially is dumped through the SSMEs and 30 seconds later via the liquid oxygen fill and drain valves. This dump is performed without helium pressurization and relies on the self-boiling of the trapped liquid.