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The Mighty H-Valve
A veteran technical diver shares his reasons for using H-Valves when diving recreational profiles

Bottom Line

The H-Valve provides divers a fully redundant regulator set (a backup first and second stage), which provides a level of safety not afforded by the traditional J-Valve (one first stage and second stage with a backup second stage) configuration.

Scuba has been around a long time and a look at the evolution of tank valves can be an interesting journey. Aside from the traditional scuba cylinder “K” Valves that come in two configurations (DIN and INT/Yoke), there is a history of tank valves that take their names from other letters in the alphabet, including the “J” Valve, “Y” Valve, and the “H” Valve.

We here at ATA/BAR Divers have dived thousands of times around the world; running into an H-Valve diver is a rare thing, but on a recent trip it happened! Rick is a Florida-based diver with some 2,500 dives over three decades as a recreational and technical diver and instructor. He is a firm believer in H-Valves. We asked him why:

I don’t want just an octopus for my backup, I want a full regulator set—that is a 1st stage and 2nd stage—as my backup air delivery system. The H Valve gives me that extra margin of safety. When diving with a second tank, like a pony bottle or sling tank, is not an option, the H-Valve is the next best thing.

Rick points out the big advantage of the H-Valve (a close cousin to the Y-Valve) over the traditional K-Valve: a second 1st stage. Being a self-reliant diver for much of his time underwater, Rick’s proximity to another diver is, at times, scant. His experience as a tec diver, including early rebreather systems, has certainly had an impact on his decision to have a fully redundant air delivery system:

Since I started tec diving, I’ve had redundancy drilled into my head. When I stepped back from diving the deep stuff it seemed only natural to keep my redundancy habits intact. In my mind, sure, we [typical recreational divers] have a second 2nd stage but only one 1st stage. The most important diving component—that 1st stage—has no redundancy. It did not make any sense. I dive alone and there are times when my diving partner and I are ‘same ocean buddies.’ So, it’s either a pony bottle or an H-Valve for me.


While high-quality and well-maintained scuba equipment rarely fails, things do happen. In the real world, there is no such thing as a piece of scuba gear that is immune to failure, but there are limitations to how safe you can make diving, short of not diving at all. Rick discusses additional safeguards:

Diving with a pony doesn’t make much sense for me. I try to dive the ‘Rule of Thirds’ so running out of gas is lesser concern for me personally.


Another thing I’ve learned is not to have two matching regs. There have been times when one reg worked much better than the other in difficult conditions. The H-Valve gives me options I would not have with a single reg setup.


If there is a malfunction with one 1st stage, such as a free flow, Rick can easily isolate the regulator set by turning off the air supply. Both valve handles are easy to reach for Rick and he can turn on or off either valve with little effort. And, yes, Rick has experience with equipment problems:


Yeah, I’ve had a free flow… in bad current too! It’s no big deal with a redundant regulator set and an H-Valve to handle this situation. I’ve also tested my skills and have made my reg fail at depth to see if I can make it to the surface on only that 1st stage. What is practiced in class is in no way like trying it at depth. I quickly realized I couldn’t breathe off my 1st stage on a free flow to the surface while controlling buoyancy, dealing the current, as well as monitoring my pressure and everything else. That’s why I like the H-Valve. Problems with a reg? Just shut down the valve and the problem solved.


When he enters the water, both of Rick’s valves are fully open. The only time he would shut one down is if in case of a malfunction.


H-Valve divers need to remember that if the primary regulator set malfunctions and is turned off, the submersible pressure gauge (SPG) and low-pressure inflator (LPI) will no longer work unless redundancies are built in. Regardless, without an operational backup regulator, the dive must be terminated with an immediate and safe ascent to the surface.


In the diving world, there is no shortage of opinions as to what is right and what is wrong. Unfortunately, some divers have a tough time seeing the big picture when confronted with out-of-the-mainstream gear configurations. Rick says his gear does generate questions on dive boats:


Many recreational divers have never seen an H-Valve before, so sure, I get questions and I try to answer them all… Most questions are about what it is, why I use it, and what the advantages are. Sometimes I do get a strange look when I give them my answer, then they pause and think... Clearly the thought of a failed 1st stage had never crossed their minds before.


Have you suffered a faulty 1st stage? Do you always keep your buddy with a two-second swim distance as recommended by PADI? While a fully redundant air supply is most ideal, dragging around another tank and regulator set (a tec diving norm) is not reasonable for most recreational divers. The H-Valve gives divers looking for an additional safeguard—another 1st stage—against breathing system failures in the recreational diving arena.

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