First stage flooding, possibly how to avoid it

[Dtaine]

So I'm looking at getting a 40cf pony bottle which I'll be slinging (sole purpose as redundant gas since I'm currently diving a single tank and stuck with instabuddies).

I've read that the regulator first stage on a pony is more likely to flood since the tank's turned off until you need it, my question is if you pressurize it before the dive (final air/reg check) and turn off the tank, but don't purge the air from the regulator will it be less likely to flood during the dive?

I can see some of the arguments against doing it:
1) If the air from the regulator was purged because of a collision/current it might confuse other divers (I really don't see myself getting confused by it)
2) It could depressurize while entering the water because of a surface free flow (although not really an issue, just defeats the purpose of leaving it pressurized)

Any other reasons why it wouldn't be a good idea? Would it even have an effect on the likelihood of flooding the first stage?

I posted this here because I'll be taking GUE Fundamentals in the Spring and am looking from input from DIR/GUE divers.

 

[Redshift]

I carry mine pressurized and turned off.

 

[Bismark]

So I'm looking at getting a 40cf pony bottle which I'll be slinging (sole purpose as redundant gas since I'm currently diving a single tank and stuck with instabuddies).

I've read that the regulator first stage on a pony is more likely to flood since the tank's turned off until you need it, my question is if you pressurize it before the dive (final air/reg check) and turn off the tank, but don't purge the air from the regulator will it be less likely to flood during the dive?

I can see some of the arguments against doing it:
1) If the air from the regulator was purged because of a collision/current it might confuse other divers (I really don't see myself getting confused by it)
2) It could depressurize while entering the water because of a surface free flow (although not really an issue, just defeats the purpose of leaving it pressurized)

Any other reasons why it wouldn't be a good idea? Would it even have an effect on the likelihood of flooding the first stage?

I posted this here because I'll be taking GUE Fundamentals in the Spring and am looking from input from DIR/GUE divers.

Short answer is that GUE divers don't use pony bottles.

I also think you may be talking about the second stage, not the first stage??

However, assuming you are talking about the second stage, your question is still relevant for a deco bottle or a stage bottle. Your first and second stage will not flood if it is pressurized. The internal pressure will be higher than ambient so.......

If by chance you bump it and it depressurizes, no big deal. Just repressurize it. You will learn that flow checks should be done about every 5 minutes (and other times, but for sure every five minutes) and since this flow check consists of ensuring all regulators are powered and shut off (except for back gas and if applicable, bottle you are breathing from) you will catch that your reg is depressurized.

Don't worry about the "confusion" aspect for other divers. If your regs are not powered, the amount of bubbles will be small and of short duration.

Don't worry too much about flooded regs. Far better to have a flooded reg than no gas............

Good luck in Fundamentals.

 

[Dtaine]

I carry mine pressurized and turned off.

I had never heard it discussed, so I wasn't sure if it was common practice.

A couple questions though:

Have you ever had it depressurize entering the water (the result of a surface free flow perhaps) - and if it did would/did you just turn it back off and then on again to re-pressurize it?

 

[Dtaine]

Short answer is that GUE divers don't use pony bottles.

Yep - knew that one, I'm getting a 40 so I can use it when I get into technical diving in a few years as well (a bit a ways away, but why not plan ahead).

Although I guess it could be used as a stage on shallow recreational dives - hehe. Now that should illicit some response (I'm kidding people)

I also think you may be talking about the second stage, not the first stage??

Well, I had read about first stage flooding (I'm gonna have to find where that was again) - wasn't as concerned about a second stage flooding.

 

[nadwidny]

Have you ever had it depressurize entering the water (the result of a surface free flow perhaps)

Yes

- and if it did would/did you just turn it back off and then on again to re-pressurize it?

Yes

 

[rjack321]

There are plenty of fundies level and up divers in Miami. PM "deepstops" he might be able to help set you up with some buddies.

Get an AL40 bottle, it will be more useful down the road.

 

[TSandM]

Flow checks every five minutes? Is that something one encounters at the T1 level or above? Because I have never been taught that . . . Flow checks before submerging, after any contact with the overhead, after any manipulations of valves, and Danny had us do one on reaching the mainline. But nobody has ever taught me to do flow checks every five minutes. Is that only for the deco bottle(s)?

 

[RJP]

my question is if you pressurize it before the dive (final air/reg check) and turn off the tank, but don't purge the air from the regulator will it be less likely to flood during the dive?

Yes - that's the way to do it.

 

[jeckyll]

Lynne,

Dan mentioned during our fundies class that you should check your valves periodically during the dive... about once every 5 minutes. Of course Guy could be referring to something after that time as well, he'll have to comment

Bjorn