These Cabin Pressure Relief and Isolation Valves are
representative of a larger suite of components including manual and
motor driven isolation valves, regulators, relief valves, pressure
sensors, and flow restrictors.
The Quest Joint Airlock is a pressurized space station module
consisting of two cylindrical chambers attached end-to-end by a
connecting bulkhead and hatch. The airlock is the primary path for
International Space Station spacewalk entry and departure for U.S.
spacesuits, which are known as Extravehicular Mobility Units, or
EMUs. Quest can also support the Russian Orlan spacesuit for
The Joint Airlock acts as a stowage area for spacewalk hardware
as well as a staging area for crewmembers preparing to conduct a
spacewalk. A combination of the depress pump and pressure
equalization valves located within the hatches accommodate the
depressurization/pressurization capability of the airlock.