Open or closed valve on pony bottle?

[TMHeimer]

There's a previous thread somewhere--same question. Differing opinions with I think open winning out.

 

[sunnyboy]

A stage should be charged (valve open to pressurize 1st stage) then closed. That keeps water out. By definition a stage is something you use at a specified point in the dive, so having the valve closed until you need it should not be a problem. It's a good idea to check the SPG periodically to be sure it hasn't lost pressure.

Rebreather divers carry something called a bailout. Physically it can be the same tank & reg you use as a stage, but the difference is bailout must be available instantly. Therefore, you dive the bailout with the valve open.

 

[PSUSciDiver]

I charge then turn the valve off because thats how I was trained. I don't have a ton of dives using a pony but I have never accidentally purged its second stage. Recently I had a Tec instructor recommend adding one of those inline shutoff valves some times called a free flow valve. I have been considering his advice.

 

[sunnyboy]

I charge then turn the valve off because thats how I was trained. I don't have a ton of dives using a pony but I have never accidentally purged its second stage. Recently I had a Tec instructor recommend adding one of those inline shutoff valves some times called a free flow valve. I have been considering his advice.

Everyone has a different view on these, but my training was to avoid adding failure points. I consider those inline valves to be an added failure point, so I won't use them.

 

[oldschoolto]

Part of diving with a pony is to keep a eye on it... I don't use the little button pressure gauges for that reason... They would be fine on a stage bottle... I sling the pony across my body so it's easy to control in a wreck and the SPG is right there in plain site....

Jim...

 

[dumpsterDiver]

I charge then turn the valve off because thats how I was trained. I don't have a ton of dives using a pony but I have never accidentally purged its second stage. Recently I had a Tec instructor recommend adding one of those inline shutoff valves some times called a free flow valve. I have been considering his advice.

I have no tech training, but that sounds like a really bad idea. You add failure points, expense AND the potential for confusion during an emergency. And what benefit does this extra device provide? I'm not really sure.

The complexity could kill you.. What if you have the valve on, the shut off switch off and you try to inhale in an emergency. you get nothing, so you get confused and think the tank valve is off(even though it is on) and in your confusion, you try the valve one way and then finally the other.. now you have shut the valve off.. try again and get nothing... then you think .. oh yeah the shut off valve, so you open that and inhale and get half a breath and then nothing....then you switch positions on the shut off valve and try again and get nothing. Then you turn the tank valve on and try to inhale .. and.. you get nothing (because the in-line valve is off) Are you confused yet? How about when you are cold, tired, scared, narced and have empty lungs?

I would wear the sling bottle with the tank on, but if you want it off, I don't have a huge problem with that, but adding an in-line valve seems to score really low on the risk versus reward scale.

Oh yeah... and if you have one of those inline valves, then you probably need to add an over pressure relief vlave on your first stage (so the hose does not explode when you have a little creep in pressure from the first stage) ... so more failure points and cost.

 

[hroark2112]

Everyone has their own opinion. The only wrong way is the way the guy does it who disagrees with you.

If I am diving with a pony, the valve is open. IMO, it's of no use to me if I can't immediately go to it in an emergency. I did this even before I began rebreather diving, and I still do it this way.

If you don't do it my way, you're going to die.

 

[uncfnp]

Choose one and use it consistently. And practice with it.

If you are prone to feeling rushed and tunnel vison under stress, leave it on.

If you handle stress well, have a small bottle or a first stage you can not easily detune. Consider leaving it off, pressurized and check/cracked throughout the dive or at least after you enter the water. Bumps here can trigger a flow.

 

[stuartv]

If it's my redundant breathing gas, the valve stays open. Would you dive doubles and keep the left post turned off?

If it's deco gas, it's charged and then turned off until needed.

 

[sunnyboy]

Everyone has their own opinion. The only wrong way is the way the guy does it who disagrees with you.

If I am diving with a pony, the valve is open. IMO, it's of no use to me if I can't immediately go to it in an emergency. I did this even before I began rebreather diving, and I still do it this way.

If you don't do it my way, you're going to die.

I would agree with you except we probably don't dive the same rebreather, which automatically makes you wrong.