Quote: (Originally Posted by
dave t)
I saw the new voyager a couple of days ago and it does use a normal compensating first stage but no needle valve. The flow is set before diving and as far as I could see is not adjustable once underwater. Aledgedly the flow remains stable even though the IP increases!!
The voyager, from his first appareance as a prototype, is using a normal first stage without any sealing that change the IP with the depth.
It does use a needle valve that the user preset at surface and can't adjust during the dive.
The IP of the first stage is normally set to +4 or +5 bar and the flow is usually set quite low (0.5) at surface.
I tested the voyager needle valve personally with a first stage that can change the IP, two pressure gauges, one additional needle valve, a bucket of water and a flow meter.
The result is that the flow of oxygen increase with the depth.
I made a test with the same setup using with a Kiss valve instead of the needle valve and the flow didn't changed until the ip was more than 2 time the pressure after the orifice, then started to decrease, according to the theory.
If someone has a swagelok needle valve with 1/4" tubing connection for sale at very low price, i am interested to buy it, to check it with the same setup.