Can a regulator breathe too easily?

[luis]

Mouthpiece valves, and even the bare valve cage cause a noticeable increase in breathing effort. I really like the way my regs perform when I dive without the inlet valve... really smooth and open feeling. Try it sometime and you might be surprised at the difference in performance.

To eliminate the air resistance of the spokes in the cages(wagonwheels)I have completely removed the spokes from a couple of cages, essentially turning them into just a bare piece of tubing to support the mouthpiece tube.

I haven't run into any problems with this arrangement yet, but would like to hear from others that have tried this. Any problems clearing out the water, etc?

That is not what I have measured with the new valves and cages.

With the old valves, I could measure as much as 0.3 inWC pressure drop across the valve while taking a strong breath. With the new valves it is barely 0.1 inWC. Sometimes, it is actually hard to measure.

I don’t like getting water in my regulator, so I personally don’t think it is worth the hassle to not use mouthpiece valves.

With the performance of this new regulators, I am actually counting on that little bit of flow resistance of both mouthpiece valves and the duckbill eliminator, in order to control any light free-flow from such a low cracking effort.

[luis]

OK, well, Luis, et al, just for reference, where are you guys taking your suction on your Magnehelic gauge. I am taking mine from a fitting between the mouthpiece and the can outlet, not, at the mouthpiece. I do this, right or wrong, to remove differences due to various cage valves etc. I thought this to be a more pure reading, only influenced by the diaphragm and mechanical bits?

So, my Phoenix RAM HPR is cracking at .4 inches. IP around 130 to 135. This of course is with the new "super flex" diaphragm. No shims installed. If I take the suction at the mouthpiece it is closer to one inch, maybe like .7 to .9. This is an old mouthpiece with the stiff neoprene cage valves, I just use it in my test rig.

One thing I notice is the strong venturi, as soon as the reg begins to flow at .4 inches, the suction actually drops off to near zero. This is only noticeable with the suction being taken from between the mouthpiece and the can outlet.

What is the wisdom on this, not sure I have ever head a reg flow at .4 inches before.

Nem

I do the same thing…
Actually, it really depends on what I am measuring. I have a set up with about 8 inches of smooth clear tube with a test port halfway down the tube. This set-up eliminates variations from the corrugated hose assembly, etc. This allows me to do comparison test of just the regulators.

I also have set-ups to test the flow resistance at the mouthpiece, etc.

[antique diver]

Luis, that sounds like the best way to compare regulator to regulator on the bench. Still, I like to test the inhalation effort at the mouthpiece with the hoses and valves that I will actually be using on a given regulator. That shows me how that regulator is performing with its actual accessories taken into account... such as the turbulence caused by the corrugated hose, the valve cage and inlet valve. The test mouthpieces I use include the old style straight as well a curved AquaLung model. Each of these testors has a brass hose adapter installed into the main body that accepts the 1/4" ID hose going to my Magnahelic gauge. It measures what I am actually feeling in the way of breathing resistance.

While the better regulators do breathe fine with the proper valves installed, my marginally performing regs noticeably benefit from the removal of the inlet cage and valve. After all, some of them came from the factory that way!

I readily admit to preferring the safety of the valves being in place, but have yet to incur an actual problem while not using them. So far I have not had a problem clearing them after intentionally letting the MP flood, but I realize that is a potential hazard.

With an open mind, I hope to hear from more of you with your experiences and advice on this subject!

[EHowe]

Could you guys post some pic's of how you rig your mag guage inline for the tests?

[Nemrod]

Could you guys post some pic's of how you rig your mag guage inline for the tests?

This is one of several variations I use. This is the one I am using for dh regs. The supply hose from the regulator slips over the end of the PVC Tee. A mouthpiece with cage valves slips into the other end. The "Minihelic" gauge takes suction from the small brass barb on the Tee.



For single hose, I have a similar Tee with a rubber sleeve to fit over the mouthpiece port and the other end of the Tee was squashed after heating to hold a mouthpiece. Works the same way.


I am afraid that .4 inches is too low for the real world, oh woe is me, my regulator breaths too easy

Nem

[luis]

Luis, that sounds like the best way to compare regulator to regulator on the bench. Still, I like to test the inhalation effort at the mouthpiece with the hoses and valves that I will actually be using on a given regulator. That shows me how that regulator is performing with its actual accessories taken into account... such as the turbulence caused by the corrugated hose, the valve cage and inlet valve. The test mouthpieces I use include the old style straight as well a curved AquaLung model. Each of these testors has a brass hose adapter installed into the main body that accepts the 1/4" ID hose going to my Magnahelic gauge. It measures what I am actually feeling in the way of breathing resistance.

I have a similar set up, that I use when I am testing the hose assembly, including mouthpiece valves, wagon wheels, etc. I also made a set up were I was using two of my Magnehelic gauges to measure pressure drops across the mouthpiece valves.

I have several Magnehelic that I use for different measurements, but I still don’t have a good flow meter. I know which one I want to get… I just haven’t gotten around to it. I haven’t even made the time to install a second meter on my bench (it is in a portable set-up). Someday I hope to organize my bench…

While the better regulators do breathe fine with the proper valves installed, my marginally performing regs noticeably benefit from the removal of the inlet cage and valve. After all, some of them came from the factory that way!

I readily admit to preferring the safety of the valves being in place, but have yet to incur an actual problem while not using them. So far I have not had a problem clearing them after intentionally letting the MP flood, but I realize that is a potential hazard.

With an open mind, I hope to hear from more of you with your experiences and advice on this subject!

My issue is not so much safety as it is that I just don’t like salt water inside my regulators… I dive salt water most of the time up here in Maine.



That being said… now that I have been diving with the HPR for several months, I can say that I thrilled with the convenience of opening and closing the cans of my Phoenix HPR without having to line up the diaphragm. I always new that it was a bit of a hassle, but it was just part of diving a RAM… Well, I am keeping two original RAM with their original second stage, but my “go to” regulators are all Phoenix HPR and I could not be any more please for the convenience (and performance).

I use thumb screws on the clamps at the horn and a thumb screw on the body clamp. I can open and close my regulator literally in seconds. I actually do it all the time as show and tell when other divers ask me about it.

[antique diver]

I used to be worried about salt water getting inside my double hose reg cans, then I realized that my single hose regs such as an MR12-3, Conshelf, etc., have essentially the same parts exposed to the water on every dive.

Really the only mechanism that stays dry in normal use of a single hose regulator with a diaphragm first stage is the HP mechanism between the air inlet and the 1st stage diaphragm.

That is the same part of a double hose regulator that would stay dry even with a flooded can. So, I just don't worry about it any more, but do rinse them out well after salt water use. That said, I must admit that my own DH regs see more fresh water than sea water during a normal year.

Luis, I like your use of clamps and screws that you can use without tools to easily open your regs and remove hoses.

[luis]

All my Conshelf first stages and my wife’s Titan first stages have dry environmental seal chambers.
Single hose second stages are design to allow easy flushing and up here I try to rinse them with fresh water while they are still wet (as soon as possible).

I don’t really worry about it, but I do like to avoid corrosion. I only like to service my regulators when they need to… That could be many years between service.

Allowing water into the chamber kind of defeats one of the basic advantages of a double hose regulator… the fact that the first and second stage are environmentally sealed. This is an advantage that no single hose regulator (with the present common geometry) can ever accomplish. This advantage is one of the key points to the higher reliability of a double hose regulator.

Double hose regulators are notorious for their performance in cold water and their extremely high resistance against freezing. This advantage is lost if you allow any water in the case.

I personally had a RAM freeze on me under the ice due to water inside the case (less than a teaspoon of water). The worst part was that I didn’t believe that it was possible and since the bubbles from the free flow where coming out the exhaust (and I could not see them), I didn’t take action as early as I should have.

In the conditions where I dive regularly, is not that I worry about it, but why ruin one of the primary advantages of a double hose.

[SurfLung]

- I finally installed my second HPR and combined this one with the new diaphragm. I asked Drado for a straight forward configuration that I shouldn't have to keep tweeking and adjusting... Here's what I did:
- The set up is the standard install and IP pressure but with one port blocked and the new diaphragm installed. I adjusted the lever height to be level with the can.
- Attached to 3000 psi tanks, it breathes super easy. Same tanks with a well tuned (non hpr) DAAM and I can tell a remarkable difference. I have to compare it to a non HPR/non New Diaphragm Phoenix... Still have one of those!
- I have not tested this in actual water and diving... Hoping it doesn't free flow!

[Drado]

With one port blocked, if you breathe in hard enough on the surface and remove your lips, you can get it to freeflow - which stops as soon as you block the mouthpiece again. I sorta like the venturi that strong. Initially, I too was worried that it might free flow at depth, but after taking it around again last week-end, I'm happy to report that there were no free flows.

[luis]

With one port blocked, if you breathe in hard enough on the surface and remove your lips, you can get it to freeflow - which stops as soon as you block the mouthpiece again. I sorta like the venturi that strong. Initially, I too was worried that it might free flow at depth, but after taking it around again last week-end, I'm happy to report that there were no free flows.

That is correct.

I sometimes induced an intentional free flow after a dive to allow some dry air to blow out. I haven't done a true control experiment, but I do think that it helps dry the intake hose if any moisture got in there. The only problem is that it does seem to dry the moisture, but in salt water, it does leave the salt behind; at the end, it wasn't a great idea. But it is still kind of cool.

[SurfLung]

- Last night I compared it to my Faux Navy (non HPR) Phoenix and to my Green HPR Phoenix. The new one with one port blocked and new diaphragm was a very clear and dramatic difference... Better than both of the comparison regs. I could feel the increased venturi flow.
- I didn't see this dramatic improvement in my first HPR install and apologize for not trying harder with adjusting... I've never been unhappy with the breathing of any of my regs... Mistral, DAAM, PRAM... And the Green PRAM install was AT LEAST as good as my PRAM... Just not noticeably better. This second install has OPENED MY EYES TO WHAT I WAS MISSING!