What function do the two large, chunky red valves on the center of the Soyuz control panel have? They are located in the lower middle of this image, just above the Vizor periscope. I wish to know what each one does, and how and when they are used by the cosmonauts during a flight. The more detail the better :)

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  • $\begingroup$ I think they were used in the film "Gravity" Whether that usage was accurate is a different matter $\endgroup$ – JCRM Aug 1 '19 at 7:10
  • $\begingroup$ If I remember right, in the movie they turn them to cut off and restore the flow of air, but I suspect there's some artistic license there, especially regarding her reactions. I do suspect that they are related to cabin air in some way, as I saw a video from a soyuz simulator where they turn these as part of an exercise to extinguish a fire. But I'm hoping for more detail. I guess they add o2 or n2, and there's a separate cabin relief (perhaps the third red handle on the right?) $\endgroup$ – Innovine Aug 1 '19 at 7:21
  • $\begingroup$ Views, slightly different construction: youtube.com/watch?v=boPOZGD8WzY and gizmodo.com/… $\endgroup$ – user10509 Aug 1 '19 at 8:19
  • $\begingroup$ I suspect their marked names (RPV-1 & RPV-2) stand for Pressure Release Valves -- they are marked above with OTKP (open) and below with 3AKP (shut). $\endgroup$ – amI Aug 1 '19 at 11:57
  • $\begingroup$ There's some info in the Soyuz Crew Operations Manual (linked elsewhere on this site) but it's cryptic, at least to me. The valves are referred to as РПВ 1 and 2, which is listed as both Air Flow Regulator and Manual Air Supply in the acronym list. There's no schematic for this system in the manual. My guess is that they allow O2 to flow into the cabin from a regulated system, but my Russlish isn't good enough to be sure. $\endgroup$ – Organic Marble Aug 1 '19 at 12:20

They are Manual Turn Valves 1 and 2, РПВ-1 and РПВ-2. (Soyuz Crew Ops Manual p. 24). They enable moving oxygen from tanks in the service module to the oxygen supply duct. source.

The crew ops manual contains a couple procedures involving them - e.g. closing them to determine presence of leaks.

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    $\begingroup$ "pumping"? Are there O2 pumps, or a regulated system? $\endgroup$ – Organic Marble Aug 1 '19 at 13:02
  • $\begingroup$ It doesn't really say what they DO though. I guess from the description of the leak check that they allow O2 and N2 to gently flow into the cabin if the pressure is below 1bar?, so they turn these off during the leak check. I know the Shuttle has two valves which top up the cabin pressure like this.. seems reasonable that these do the same? From the procedures it sounds like these are left open, so its probably not high pressure gas coming in. Which leads to the next question.. how do they vent the cabin gas, and rapidly refill it, if they can? $\endgroup$ – Innovine Aug 2 '19 at 7:54
  • $\begingroup$ @OrganicMarble: No, I don't know - the original wording is 'filling the central bus from the tanks' $\endgroup$ – SF. Aug 2 '19 at 15:35
  • $\begingroup$ @Innovine: Hopefully someone provides a better answer - this is all I found. Seems though like they serve only oxygen, to replace scrubbed CO2. I didn't find anything about nitrogen. $\endgroup$ – SF. Aug 2 '19 at 15:38
  • $\begingroup$ A schematic would be nice, but I can't find one either. I agree with @Innovine that they are likely connected to what we called on shuttle the 'cabin regulators'. $\endgroup$ – Organic Marble Aug 2 '19 at 15:44

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