Equipment failure and response: The free-flowing regulator

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Ricky B

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Introduction

Many times I see a thread with a post about an equipment failure and the responses are to take some action that was purportedly learned and drilled in the open water class. Most often, I don’t remember any such drill being taught, and many other posters indicate that they don’t either. If the drill is taught, the amount of time devoted to it is so short so that when the need arises, say, five years later, there’s no recollection of the needed skill.

That led me to the conclusion that there are a number of common equipment failures that can readily be addressed by standard responses but not all of us know them.

Now some may say that there are plenty of threads on various equipment failures—just search for them. Well, I have, and I can say that (1) the search function on ScubaBoard is primitive, (2) going through numerous threads is tedious, particularly since many of which threads that turn up in a search result out to be off-topic, and (3) advice given in one thread contradicts advice given in another.

More important, divers without a lot of experience often don’t know to search for information on equipment failure (before it happens). You don’t know what you don’t know.

In the interest of helping new divers and those new to the board (not to mention wanting to learn more myself), I gathered what I call the collected wisdom of ScubaBoard and distilled it in this post. I make no claim that the comments in this post are definitive and certainly not original with me. I shamelessly cut and pasted other people’s posts and did some editing.

I am posting this for feedback and maybe we can get a sticky or a FAQ out of this thread.

The problem: regulator starts to flow freely under water.

First, for the new diver: regulator problems are uncommon. But problems happen, and you should know how to deal with them. The most common problem is the free flow.

A free flow is when the regulator spews forth air on its own. Under water, it can create violent bubbling.

This is not necessarily an equipment failure: regulators are designed such that they will free flow when the regulator mouthpiece faces up under water. If a regulator starts to free flow when in the water, simply turn it so the mouthpiece faces down. Under water that usually does the trick. If not, cover up the opening in the mouthpiece with your fingers, and that will usually create enough backpressure to stop the free flow.

Sometimes when you push the purge button (whether in the water or not), the regulator will free flow. Same procedure. Turn the regulator face down, and cover up the opening in the mouthpiece with your fingers.

As simple and as basic as this is, I have been on dive boats with certified divers who did not have a clue as to why the regulator was free flowing or how to stop it. So in addition to this post being for new divers, it is also for the dive tourist who dives a few times every couple of years.

The purge button doesn't have to be pushed by the diver. If the diver is facing into the current, the pressure of a strong current on the purge button can cause a free flow. Once again, this is not an equipment failure. Put the palm of your hand across the second stage to cover the purge button so the current doesn't depress the button anymore. Or turn your head (and thus the regulator) at a slight angle to reduce the impact of the current on the purge button.

An equipment-failure free flow typically occurs when there is sand or grit in either the first or second stage, when the pressure settings are out of adjustment, or when a part fails.

A free flow can also be caused by an icing-up of the first stage (a common cause of free flows at depth in cold water). Free flowing because of cold air/cold water are dealt with separately below.

Diver response

Let’s assume the turning the regulator so the mouthpiece faces down and covering the opening of the mouthpiece doesn’t work. Don’t freak out. It may be an easily solved problem.

1. For some people, smacking the regulator on the side a couple of times with the fleshy part of the base of the thumb on the palm of the hand works (in which case it was probably some grit caught in the mechanism). If that doesn’t immediately solve the problem, take the next step.

2. If you’re not next to your buddy, move closer! If you can’t sort out the problem, you’ll need to be able to use your buddy’s alternate second stage (octopus). Watch your buoyancy and maintain contact with your buddy.

Assuming you don't think your regulator has frozen because of cold water (see below), your next step is to make a safe, controlled ascent to the surface.

You do need to act quickly. A free-flowing regulator can empty a full 80 cu. ft. cylinder in a minute and a half to three minutes (depending on depth). But if you can get 60 seconds of breathing before going on your buddy’s octopus, you can be 30 feet closer to the surface in a 30 feet-per-minute ascent.

Keep in mind that as the tank empties, buoyancy can change up to 5 lbs. on an 80 cu. ft. tank. So keep an eye on buoyancy.

3. You CAN breathe from a free-flowing regulator. Don’t just abandon it. (This is a skill you supposedly learned in your OW course. If not, get into a swimming pool, press the purge button to simulate a free flow, and practice.) The PADI Open Water manual says:

First, don't seal your mouth on the regulator because the continuous flow could, in the worst case, cause a lung over expansion injury, but more likely it would make the regulator pop out of your mouth and flood your mask. Instead, hold the regulator in your hand and press the mouthpiece to the outside of your lips, inserting one corner if you like. Breathe the air you need like drinking water, letting the excess air escape.​

If the free flow is not too violent, you can choose to keep the regulator in your mouth and let the regulator exhaust excess air.

In either case, if the bubbles obstruct your vision and annoy you (and they probably will), you can take the free-flowing regulator out of your mouth after you take a breath and hold it arm’s length (not holding your breath and blowing small bubbles all the while) until you need to take another breath.

(You don’t even need a regulator to breathe compress air under water! I saw a dive instructor dive to a shallow bottom (20 or 25 feet deep) holding a bare cylinder to his chest with the valve slightly open and breathing the air as it bubbled up over his face.)

4. The next step might be to get kinky (see below). This becomes more appealing if you're at 100' and no buddy is around.

If you are within the no-deco dive time limit (NDL) and at a reasonable depth, you might be able to make a controlled emergency swimming ascent (CESA) to the surface (keeping your airway open and saying AHHH all the while to avoid a lung over-expansion injury). (If you're not within the NDL, well, doctors can treat "being bent"; they don't have luck with treating "being dead.")

Getting Kinky

Some posts have suggested bending in half the hose supplying the free-flowing regulator. Just like you can put a kink in a garden hose to shut off the water flow, you can shut off the air flow that way.

Double the hose over and then slide your hand up to where it is doubled over, compressing the hose further, to stop the flow. Only kink the hose sufficiently to stop flow and don't apply needless force. Kinking the hose might damage it, so the hose should be inspected before re-use.

Kinking the hose to the second stage assumes that the free flow is caused by the second stage. But what if it’s the first stage that is free flowing—for example, a failure of the high-pressure seat? In that case, kinking the hose would probably cause your octopus to free flow. If you were to kink that hose too, you would apply the high pressure from your tank to the low pressure hose, which might burst, a small problem made larger.

If both the primary and secondary second stages are free flowing, does that mean that it’s the first stage that is causing? Not necessarily. It could be both second stages that are independently free flowing, though that would be unlikely.

If only one of the second stages is free flowing, then must it be that second stage that is the problem? Again, not necessarily. If the first stage is free flowing, only one second stage might free flow (whichever second stage is adjusted for lighter resistance). If the first stage is free flowing, then breathing on the other second stage (or purging it) could trigger a free flow there too.

Given the issues related to kinking the regulator hose, my inclination would be to do that as a last-ditch effort if (1) I had no buddy nearby and no redundant air supply or (2) my buddy was already out of air and breathing from my air supply. And then I would hope that I had the strength to kink the hose, to hold it kinked, and that it was a second stage, not the first stage, that was the problem.

Buddy response

1. Move closer to be able to offer assistance. Immediately. Don't just gawk.

2. Stand ready to offer your octopus (so the distressed diver doesn’t have to search for it and doesn’t grab the regulator out of your mouth).

3. When your buddy is on your octopus, turn off his tank’s valve to eliminate the distracting bubbles and reduce buoyancy changes.

Keep an eye on buoyancy and help your buddy make a controlled ascent.

Prevention

1. Don’t drag your regulator; clip it to so it doesn’t dangle when you walk across the beach or swim along the bottom.

2. Have your regulator serviced as recommended by the manufacturer (although a distressing number of regulator malfunctions are reported as occurring immediately after annual servicing). Test the newly serviced regulator in a pool before taking it one a dive trip and make sure it works properly.

3. Often the alternate second stage is de-tuned a bit by having the cracking pressure raised to prevent free-flow.

4. Some regulators have a dive/predive control switch. If yours has one, before entering the water, adjust the dive/predive venturi control switch to “MIN” or “Off” for the octopus.

5. Some octopus holders have a built-in plug that helps block the mouthpiece while it's in the holder, which can reduce free flows of the octopus.

6. Buy an intermediate pressure (IP) gauge and check the IP from time to time. Know the standard IP for your regulator, and if it creeps up too high over time, get it serviced. A basic IP gauge can be had for as little as $7.95.

Cold Water

Cold water and high demand on the air supply are the ingredients for regulator freeze-up, another cause of free flow.

Diver Response

If you can breathe off your buddy’s octopus, try shutting off the air from the tank, swishing the second stage in the water for a minute or two, and then turning the air back on to see if the regulator has defrosted. Of course, your buddy might be the one to have to turn the valve on your tank if you can’t reach it. So it would be a good idea to have a pre-dive discussion with your buddy about possible regulator freeze-up and the need for your buddy to turn off your air once you are on the buddy’s air supply.

Prevention

1. Use a regulator designed for cold water.

2. Don’t breathe through the regulator on the surface when the air is cold because the moisture from your breath can increase the chance of freeze-up. If diving in frosty weather, don’t put the regulator in your mouth until ready to jump in. And take the first breaths at the surface with the regulator in the water.

3. Don’t tax the air supply. Try to breathe normally, not extremely deeply or quickly. When inflating the BCD, use short bursts rather than holding the inflator button down. Try not to inflate and inhale at the same time.

Buddy response

1. Move closer to be able to offer assistance.

2. Stand ready to offer your octopus (so the distressed diver doesn’t have to search for it and doesn’t grab the regulator out of your mouth).

3. When your buddy is on your octopus, turn off his tank’s valve to eliminate the distracting bubbles and reduce buoyancy changes.

Two people sharing air at extremely cold temperatures at depth will increase the draw on the first stage and will increase the chance the buddy’s regulators will free flow too. So an alternate air source, such as a pony bottle, would not be a bad idea for diving in extremely cold water at depth.

Keep an eye on buoyancy and help your buddy make a controlled ascent.

Comments and Suggestions

Are there alternative responses not mentioned? Are some of the responses listed above a bad idea? What order should the diver’s responses be in?

So please jump in and add your suggestions, comments, corrections, and additions.
 
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The post was in the process of being edited and completed. It's now "above"!
 
There is no reason to try and breath from bubbles, keep the regulator in your mouth unless you have an alternate. The flow rate cannot exceed the exhaust valve capacity on a modern regulator. Stick your tongue in the mouthpiece if need be to modulate it. Go up, the surface is your safety zone.

N
 
Has anyone actually on ScubaBoard done this or seen it done? ------ Yes have done it.

Would the average diver able to bend the LP hose sufficiently to shut off the air? ------ Yes it is very easy to do, double the hose over and then slide hand up to the end where it is doubled compressing the hose further, it will stop the flow. I would however suggest if done only kink the hose sufficiently to stop flow and don't apply needless force.

Would kinking the hose in that fashion damage, requiring replacement? ------ Normally it shouldn't if the hose is new, or in good condition. If the hose is very old however it may damage it, but most probably it should have already been replaced if so.

If the free flow is caused by a faulty primary regulator, kinking the hose could cause the LP hose to then burst under a much higher supply pressure (than design) from the primary regulator

You could install a shutoff valve prior to the secondary regulator, however that introduces its own issues. Lack of familiarity by others with your gear, and not realising that the valve is shut. Again a faulty 1st stage could cause the reg hose to burst with the valve shut. In hindsight probably better to risk a free flow rather than the additional complication of another bit of gear to think about. I like to apply the KISS principle (Keep It Simple Stupid). The more items you have the more to go wrong.
 
There is no reason to try and breath from bubbles, keep the regulator in your mouth unless you have an alternate. The flow rate cannot exceed the exhaust valve capacity on a modern regulator. Stick your tongue in the mouthpiece if need be to modulate it. Go up, the surface is your safety zone.
N
Thats an interesting concept, but one I have never tried....way back when,I was taught to pull the left corner of the mouthpiece out to allow excess air to escape, and then tilt your head to the right to keep the bubbles from blocking your vision....that the PADI way anyway, and that's how Im required to teach it also...
 
Thats an interesting concept, but one I have never tried....way back when,I was taught to pull the left corner of the mouthpiece out to allow excess air to escape, and then tilt your head to the right to keep the bubbles from blocking your vision....that the PADI way anyway, and that's how Im required to teach it also...

See, thing is, I apply common sense, not PadI sense. You go ahead and attempt to breath from bubbles, me, I am going to keep it in my mouth. There is this thing called an exhaust valve and the excess air will spill through it. There is this thing in your mouth called a tongue and you can block the air flow with it.

As well, just kink the hose. Of course if it is a short hose and that is your only partially functioning second, then that will not work. But see, the thing about all of these Scubaboard scenarios, in some 40 plus years a sport diver, I have seen very little of this needed, much less breathing off of bubbles.

Can it be done, yes, is it needed, no.

So, let me get this straight, Padi has teaching open water divers to breath from bubbles but has them kneel on the bottom while doing it? You will have to excuse me if I do not care what Padi says and I am way beyond the point in time where I rely upon what instructors do or say.

I mean no disrespect to you, I am sure you are a fine and conscientious instructor just trying to do the best you can for your students. I think the best thing to teach them is for them to beat a hasty retreat back to the surface on either their octopus or their buddies and forget the malfunctioning bubble blower. Let it blow, it does not matter. This is the Basic Scuba forum and we are not in overhead.

I could be wrong and occasionally, I am.


N
 
Nice post.

As a relatively novice diver, I had a violent freeflow. I had practiced the "breathe from a freeflowing regulator" skill in OW. Nonetheless, I was not prepared for the horrendous noise and the reduced visibility that came with the torrent of bubbles.

My buddy donated, and we ascended on his regulator. It would have made the experience much easier to cope with had we shut off my tank valve.
 
See, thing is, I apply common sense, not PadI sense. You go ahead and attempt to breath from bubbles, me, I am going to keep it in my mouth. There is this thing called an exhaust valve and the excess air will spill through it. There is this thing in your mouth called a tongue and you can block the air flow with it.

As well, just kink the hose. Of course if it is a short hose and that is your only partially functioning second, then that will not work. But see, the thing about all of these Scubaboard scenarios, in some 40 plus years a sport diver, I have seen very little of this needed, much less breathing off of bubbles.

Can it be done, yes, is it needed, no.

So, let me get this straight, Padi has teaching open water divers to breath from bubbles but has them kneel on the bottom while doing it? You will have to excuse me if I do not care what Padi says and I am way beyond the point in time where I rely upon what instructors do or say.

I mean no disrespect to you, I am sure you are a fine and conscientious instructor just trying to do the best you can for your students. I think the best thing to teach them is for them to beat a hasty retreat back to the surface on either their octopus or their buddies and forget the malfunctioning bubble blower. Let it blow, it does not matter. This is the Basic Scuba forum and we are not in overhead.

I could be wrong and occasionally, I am.


N

I think you just misunderstood me...the regulator stays in the mouth, you just pull the corner out ..I believe the reasoning is so that you don't get force fed too much air....as a PADI instructor, I'm required to teach it that way.

I wont debate the pros and cons on an open forum..:)


EDIT: I took no offense to anything you said....this is a valid discussion that perhaps we can all learn from
 
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Shut your tank valve down. When you need to take a breath, crack open the tank valve and shut it down again. Repeat as needed, switch to your back-up reg/octopus as well if the unregulated flow of gas from the malfunctioning primary reg is too much to handle.

Perform this tank valve "feathering/modulation" technique while doing a CESA (if your buddy is nowhere to be seen and you're essentially solo). . .

With your left hand, slow your CESA rate via BCD/wing hose deflator dump button . . .with your right hand reach back, feather/modulate your tank valve and take breaths as needed.

All it takes is practice (and IMHO --should be a mandatory skill taught in basic open water courses. . .)

The motivation after realizing that you can breath off a catastrophic non-fixable free-flowing 2nd stage reg, is to shut down the tank valve to stop further hemorrhaging of precious breathing gas. Crack the tank valve, take a breath as needed and shut down the tank valve, modulating the valve while performing the CESA as described above.

Actual incident that happened:
Cozumel 2006, my adjustment knob on the second stage blew-out resulting in a catastrophic nonfixable free-flow, on a single-tank dive in 6m of depth, during a weightbelt lead check. I actually could see the gauge pointer/indicator hand on the SPG sweeping from 200 through 150 bar literally in an instant before reaching back to shut-off the cylinder valve. Switched to my bungied back-up reg around my neck and then modulated/feathered the tank valve behind my head while doing a CESA. (Again, this should be a skill regularly practiced starting in basic open water).
 
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