Regulator Free Flow

[chrisch]

You can buy devices that stop freeflows. I have no experience of them - perhaps someone can comment. Regulators should not free flow - if they do there is a problem with them. I have never had one in a couple of thousand dives or more over 20 odd years.

 

[Neilwood]

My instructor did teach on how to properly breathe out of a free flowing reg. My question was brought about mainly because I saw it happen at 60+ ft. The guy it happened to panicked. I believe I was trained well in the matter. I'm just attempting to see if there are any other tips and tricks outside of what I was taught.

If you are still concerned, practise the procedure as you were taught on your course (say on your safety stop). Simulate a freeflow (by using the purge button) and sip air from that supply. Please tell your buddy you plan to do this first though just in case they panic.

It is possible that although the other diver might be more experienced, he hasn't kept on practising his skills. This is something we are probably all guilty off to a certain extent but could, if the drills are practised regularly, make the difference between a dangerous panicked diver and someone that can take a situation that is out of the ordinary and just deal with it safely.

 

[2airishuman]

My instructor did teach on how to properly breathe out of a free flowing reg. My question was brought about mainly because I saw it happen at 60+ ft. The guy it happened to panicked. I believe I was trained well in the matter. I'm just attempting to see if there are any other tips and tricks outside of what I was taught.

1) Dive well-maintained equipment. Inspect your regs (or have a shop do it) every year and have them serviced every two years, or more often if the manufacturer so recommends. In reasonably warm water, the most common cause of freeflows is poor reg maintenance.

2) Use clean air. Ideally this would mean using your own cylinders and a single, reliable fill station, but that's not practical in the real world. Absent that, do what you can to be sure you're getting clean fills. Most dive shops are careful about air. Fire departments, less so overall but some are very good. Boat fills, it depends but it's a wet environment which makes it harder to get right. Individuals, paint ball places, non-diving shops that provide air mainly for the store owner's convenience but will do fills as a sidelne, etc., it depends, some are very good but not all of them.

3) Dive warmer water. Freeflows due to ice are a common problem in water below 35 degrees and are thought to be possible at temperatures as high as 50 degrees.

 

[2airishuman]

You can buy devices that stop freeflows. I have no experience of them - perhaps someone can comment. Regulators should not free flow - if they do there is a problem with them. I have never had one in a couple of thousand dives or more over 20 odd years.

There are inline shutoff valves that can be used to shut off a free-flowing 2nd stage. For extremely cold water where 2nd stage freeflows due to ice are common, they are sometimes used. Outside of that, they aren't recommended because they can lead to an OOA emergency if inadvertently closed. I wouldn't use one. If I were on an ice dive, I'd use H valves and two 1st stages instead and just shut down the post in the event of a freeflow.

 

[uncfnp]

I'm a new diver, and have done a few dives since being certified, but I worry about free flows. I suppose the reason why I worry is because I haven't experienced it during a deeper dive. What techniques have you found work best when encountering this?

With well maintained gear a freeflow at depth should be easy to solve. Just flip the mouthpiece down or cover it with your thumb. Or both. Absolutely no reason to panic.

The truly serious freeflows occur when a reg freezes in cold water. This is why cold water divers use gear specifically rated for those temperatures. Usually an environmentally sealed reg.

 

[Caveeagle]

ok.. I think you need to better understand what can, or typically does cause a free-flow.

a) Your worst case scenario is a first stage malfunction, allowing too much pressure (IP) to get to your 2nd stage and forcing your demand valve open. You can minimize this risk with regular service and/or using an IP (intermediate pressure) gauge to check out your regs before a trip or dive. (making sure the IP is not creeping above OEM spec)
aa) Even if your IP is stable, make sure it is within spec. IP to low can make breathing hard. IP to high can lead to free flow.

b) A 2nd stage malfunction. valve stuck open or broken. As previous comments.. Continue to breath off the flow and ascend safely. *This is a good reason to never breath past safe reserves of air/gas. You could be in world of cr@p if you have this kind of free-flow at 100' with only 500psi in your tank.

c) 2nd stage reg adjustment. With the better (newer) regs available, many have user adjustments. A dial that allows +/- to your breathing effort. Some also have a venture that can direct/alter the path of air flow to the divers mouth. Both of these can make a regulator more likely to free-flow. Typically at the surface, and when not in your mouth. You can usually turn it mouth down, or cover the opening and the back-pressure will stop it. Maybe experiment with this a few times so you are familiar with how it works.

**Maybe I missed something, but I think this covers most situations.

 

[Rooster59]

If your 2nd stage has adjustments, know how to turn off the venturi assist, and increase the breathing effort. That may stop the free flow.

 

[tr3a]

I would not use inline shutoff valves. If the freeze up is in first stage it will be of no help (and depending on equipt setup cause bigger problems).

 

[Landstander]

I haven't used it myself, but some divers attach an inline shutoff to to their regulator for this scenario. The idea is to always start with it in the open position (so that your primary and alternate second stages behave normally), while giving a fallback option to quash persistent freeflows. I don't have a position on whether or not this is a good idea, however.

I may try out one of the beasties with my pony bottle, but that's a very different scenario than what's being discussed here.

 

[redacted]

I haven't used it myself, but some divers attach an inline shutoff to to their regulator for this scenario. The idea is to always start with it in the open position (so that your primary and alternate second stages behave normally), while giving a fallback option to quash persistent freeflows. I don't have a position on whether or not this is a good idea, however.

I may try out one of the beasties with my pony bottle, but that's a very different scenario than what's being discussed here.

Shutting off your only downstream overpressure relief valve would be a big mistake.