A question of exhaust

[DrQuest]

I'm trying to figure out how regulators work. how much psi is involved in the exhausting of breath.
Trying to put it in simple terms, if I was underwater and my tanks became empty, but I still had air in my lungs, would the psi of what I still had in me be able to be exhausted through the regulator?
I'm not planning on this happening its for a project that I'm working on.

 

[spectrum]

With a normal breath in your lungs the internal pressure would be equal to the water pressure surrounding you. that is the "magic" of a scuba regulator.

If you remained at the same depth you would be able to exhale normally. It's really just a muscular action that changes your lung volume.

If you began to rise to a shallower depth which will reduce the water pressure surrounding you and if you keep your airway open the excess air pressure will escape through the regulators exhaust valve which has very low resistance. If you close your airway your lungs will expand due to the trapped high pressure air contained in them and they will rupture.

Just as the air in your lungs is at the same pressure as the air surrounding you the same is true while diving with a scuba regulator. the difference is that the pressure will vary with depth so you must let it equlibrate

Pete

 

[DrQuest]

would you know where I could find a used regulator for a great price, I don't need any hoses or other attachments, it's not going to be used by a person, it will be hooked up to a cordless vacuum in reverse with another pressurized container that would be hooked up to the mouth piece.
sorry its not an easy thing to explain, other than its an invention I've been trying to iron out the kinks.

 

[spectrum]

I'd talk to a local dive shop. They may be able to help you out with a beater. The right person might also be able to show you the workings so it's not a black box to you.

This may be helpful.

Pete

 

[David P]

the exhaust is a different part of the regulator than the inhalation. The exhaust valve is basically a thin silicone piece or rubber that folds back as you exhale. It doesn't require psi, it requires inches of water (IIRC it takes about 30 inches of water to equal 1 psi). Sometimes a piece of sand can get caught under the exhaust valve and allow water to leak in.

 

[DrQuest]

I did have a misconception of them, will need to ponder these revelations.
again thanks.