posted 04-06-2024 08:32 AM               

First of all, the context: I have in front of me two PDF documents:

• Apollo Operations handbook extra vehicular mobility unit Volume 1 system description CSD-A-789-(1) Apollo 14

• Ventilation system for inflatable pressure garments (United States Patent US3667460)

Pages 107 and 108 of the first document show diagrams of the IV pressurization/ventilation system (107) and the EV pressurization/ventilation system (108).If you look closely at the drawings, you'll see that the flow of contaminated (black arrow) gas goes up through the feet and arms to the outlet connectors via the appropriate channels.

The second document states (and I quote):

...the life support gas enters at the helmet and through ducts at the extremities of the arms and exits from the garment only through ducts located at the legs after passing over the entire body of the wearer.

posted 04-09-2024 02:30 AM               

Oxygen is fed into the suit thru the blue connector and sent to the helmet and to the horizontal distribution duct at the waist. For EVA operations the valve on the inlet connector is rotated to block oxygen flow to the waist duct and directs all oxygen to the helmet. Suit exhaust gas is collected in the gloves and feet of the suit and routed to the red outlet connector on the suit.

The diagram and description in the patent may be an earlier configuration but does not reflect what was used for the Apollo A6L and A7L suits. The configuration described in the patent requires a 4-port oxygen inlet connector plenum and the ones used for Apollo only had 3 plenum ports (one port for the cross-feed duct to the other connector, one port for the helmet duct, and one port for the valve-controlled waist duct).

I have yet to find any mention of changes in the direction of gas flow in the suit arms during suit development. The initial concept as captured in the patent apparently evolved with a reversal in gas flow in the arms. If NASA directed that change as a result of analysis or testing, then it would not be in the patent as the change was not part of the ILC invention.

posted 04-13-2024 03:37 AM               

Here are two photos sent by Mr David Mather (a few years ago, I'm not sure where they are). One, on the white liner confort:

The other apparently on the bladder:

Then for the torso ventilation ducts...

Apparently, and this is a deduction on my part, these are not made in the same way as the leg vents. It seems to me that torso channels are permeable so that oxygen can be distributed to the astronaut's chest unlike the others, which must be impermeable to evacuate stale gas.

posted 04-13-2024 10:16 AM               

quote:

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Originally posted by Apolloman:
...which must be impermeable to evacuate stale gas.

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posted 04-13-2024 02:33 PM               

The two inlet gas connectors and the two outlet gas connectors are each interconnected by plenum chambers. The ventilation ducts to the torso area and the head are connected to the inlet connectors.

Or:

The inlet connector permits the distribution of inlet ventilating gas flow to the helmet, torso ducts, and to the adjacent inlet connect (EV configuration only). The inlet connector has a butterfly diverter valve with two positional modes; OPEN , used for intravehicular operations, and CLOSE, used for extravehicular operations. The position of the valve is identified by a raised projection on the diverter valve knob, horizontal for OPEN, and vertical for CLOSE. In the CLOSE (EV) position, the inlet gas flow is directed to the helmet vent duct and in the OPEN (IV) position, the flow is divided between the helmet vent duct and the torso duct(s).

I found the document where it was written out in full:

Incoming gas is also supplied from one of the inlet connectors to the torso channels 380 and 382. These channels preferably are pervious to gas along their length so that the gas is distributed to the astronauts torso over substantially the entire length of both the torso channels to which the gas is supplied.

posted 04-18-2024 01:40 AM               

I know what this part is used for (it connects the intake connectors together and also the exhaust connectors), but I can't find any representation (photo or correct diagram) of it apart from those used in industrial ventilation.