04 July 2018

Check Valve

If you watch The Expanse you've seen a scene where a character, Prax, has his umbilical come unplugged from the ship's central air line and dumps his air.

This is a poor design.

There should be a check valve in the helmet that snaps shut when the air flow tries to reverse OUT of the suit.

There should also be a rate-check valve on the ship side.  That way when the flow rate indicates a puncture in the line, the valve closes and isolates that section from the rest of the system.

5 comments:

  1. Angus;

    You are mixing proper engineering and technical know how...with"B" movies....How could you get in the way of a good story with logic...?

    ReplyDelete
  2. Don't get me started... Too late!

    During Interstellar when McConaughey's faceplate got a leak from Matt DAAAAAYMON! cracking it: I was the person screaming, "WHERE'S YOUR FUCKING SUIT PATCH?"

    I screamed that at Apollo during a Battlestar Galactica (2000) episode too.

    I scream that a great deal at Hollywood.

    Patches are going to be standard equipment when we start living in space, so there's no excuse for not having them.

    ReplyDelete
    Replies
    1. Hey Angus;

      Don't worry, I scream at Hollywood a lot also, LOL usually with stuff involving historical movies. Also SCIFI movies.

      Delete
  3. While they could hand-wave this and say the loss was from the return line (the umbilical for space works the same way as diving umbilicals), it doesn’t change the point that in rebreathing or umbilical diving equipment today (and for decades) has had valves to prevent loss if either the feed or return lines are compromised, since for umbilical diving, a return line failure (especially up at the surface) is almost worse than a feed line failure as a simple check valve won’t work, and the pressure differential from suit to surface is usually large.

    Basically, you are right, not only do modern space umbilicals have the needed valves to prevent this (for decades), but diving systems have had it for longer, possibly going on a century (to prevent helmet squeeze)

    Bad expanse, bad!
    (And it’s usually so correct, and that’s coming from an Aerospace Engineer)

    ReplyDelete
    Replies
    1. I had not considered a return line for the suit since I was using Heinlein's "Have Spacesuit; Will Travel" model that vented spent air as a means to cool the suit.

      But I might not have been thinking it all the way through...

      Thag LURN!

      Delete

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