Upstream Regs (2nd stage) - Who still makes them...Anyone...anyone...?

[David P]

a little off track... I took the Oceanic reg class a few months ago, the instructor went into detail how easy it is to damage the Omega during disassembly, he went on and said that as long as the little switch (sorry not yet 5 am and just started first cup of coffee) thingy is working fine, dont mess with it! I thought that was a rather odd thing to say for a rebuild class....

 

[Luis H]

Sitting in on a GUE Fundamentals class, and the instructor made a big point about upstream/downstream regs, and I said that I didn't think anyone was still producing the upstream valves. The instructor said that he'd sure be interested in finding out if anyone still does - thus this thread.

Back in the early 70’s I used to teach a half day regulator repair module as part of our advance class (*), and the subject of down stream versus upstream second stage demand valve was fairly important. Even during the basic Scuba class it was covered as something important to look out for (and make sure you have an overpressure relief valve if you had an upstream demand valve).

One interesting observation, as a regulator technician at the time, was that I don’t think any manufacturer had made any upstream valves for a few years (maybe Nemrod had a few left in stock for sale). They were definitely around, but the owners were more than glad to retire them and replace them with our new Scubapro line of regulators.

From what I recall, the upstream valves (also known as “tilt valves” or “needle vales”) were very prone to leaking, but that might have also been because the ones I serviced were already old and poorly maintained. There was also no adjustment on the tilt valves. They either breathed Ok or they didn’t. Parts were already hard to find and the parts were not interchangeable between different models.



(*) Note: Yes, our standard Advanced Scuba course back then was very comprehensive. It even included a decompression chamber lecture and dive (at the chamber in Cabo Rojo, Puerto Rico). We were friends with the head of hyperbaric medicine doctor at the facility. Heck, we even talked about ice diving in that course, but only the main instructor has ever dove in cold water. The subject was not covered in any depth.

 

[jeelan]

The Xstream series are also upstream.

 

[EricQ]

I think the pilot valve in the Omega may be downstream. There is a tilt valve in the Tusa power inflator.