Regulator Shut Off Valve

[DarinMartell]

During OW we were taught to "sip" air from a free flowing reg. I asked why wouldn't I just grab my oct? The reply was that a free flowing reg bleeds off a-lot of air and it is better to use that then use even more by breathing from your safe second.

My question is why Regs don't have a shut off valve. This way if you have a problem, you just need to grab your octo then shut off the free flowing reg. That way there wouldn't be so much wasted air.

Just wondering.......

[tedwhiteva]

Shutoff valve - another failure point.

Don't agree with the reason for not using octo if primary is free flowing. If it makes you more comfortable, use it as you ascend. That amount of air use won't make the difference, and if it helps reduce stress/avoid panic, thats a good thing.

[LaCroix42]

I had the same question over in the OW section...

Dealing with a Free Flowing Regulator

[wheelman]

The reason why I have a pony setup.

[texdiveguy]

So many times a free flow issue originates at your regs. first stage in which both the primary and octo will free flow.....another case to support an on-board redundant gas source....such as a pony bottle.....'and or' an H-valve with second first stage.

[ianr33]

Apeks makes one that will fit most regulators:
Apeks Products

I have never seen one. I suppose they are not very popular beacause
1)Its something else to go wrong
2)As texdiveguy said if the problem is in the first stage then if you shut off the freeflowing primary the backup will then freeflow.

Any dive where a freeflow would be dangerous really requires redundant regs (doubles,pony etc or at the very least a competant buddy)

Apparently a freeflow can be stopped by kinking the hose,never tried that one either.

[SkuaSeptember]

To the points made by Texdiveguy and ianr33 I would like to add that anything that can be shut off that easily can easily be shut off unintentionally.
As far as concerns about "wasted air" - if you are doing a recreational dive within the normal parameters you are able at any point to make a direct ascent to the surface.If your regulator starts to free flow IT IS TIME TO END THE DIVE. The method you were taught in the pool is relatively simple and proven effective.You are not going to get a refund on the air you don't waste or a discount on your next fill.
Kink the hose? You are just introducing a weak spot that may rupture in the future.

[in_cavediver]

To answer the question of free flowing 2nd stage and why not to breathe the octo? - The answer is actually quite simple. Not all 1st stages can supply enough air to the non free flowing reg to breathe. Simply put, air will take the path of least resistance and that's the free flowing reg. If for some reason the first stage supplies more air than it can handle, you would be able to breathe it. (very unlikely though)

Curt Bowen of Advanced Diver magazine did some tests and found for a single AL80 at rec depths, it takes around 90-100 seconds to completely empty the tank. It was only a couple seconds difference to that of the tank without a reg. That's a lot of air flowing with little to no restricition.

[MLenyo]

i have a feeling nervous divers would have a terrible time with a regulator shut off valve. some of the people in my OW class were nervous enough as it was! it'd be one more thing to think of and remember. in my OW class they said it was very rare that a reg would freeflow anyway.

[cummings66]

Which is why I've seen numerous divers have a freeflow that lasts way longer than it needs to. I saw one guy lose half his air supply on a freeflow on the surface, sad sad sad.