Reg on a pony bottle question

[Teller]

I use HOG D1s on everything. Stage, deco, pony and back gas.

 

[Kharon]

I use a H2Odyssey RG2V - absolutely wonderful.

Piston First Stage - RG2V - Marine Scuba Gear Air Systems - Goodrum International

 

[Scared Silly]

While the concern of a piston vs diaphragm is certainly worth discussing. First one needs to define cold water. If you are diving in waters that are in the 30s then I would say you probably should consider a diaphragm reg. However, if you talking about waters in the 40s then the Atomic Z2 would be fine if sealed. In the 50s then using it unseal is fine.

As others have mentioned, the atomic second stages has a seat savor on them thus if unpressurized there an increased chance of water entering the reg. When I use my atomics for deco bottles (and when I dove with a pony), I just leave mine charged (i.e. the valve is always on). The second stage was near me so if it free flowed I could deal it (it never has/did).

IMHO if diving with a pony, especially when back mounted, one is better off leaving it charged. The last thing one needs to be doing is trying to turn it on when you are out of gas. If slung, things are easier.

 

[GrumpyOldGuy]

I don't see how anyone can give you a valid answer without knowing how cold of water you are planning for, 35F vs 45F are 2 different worlds.
A pony reg only needs to support one diver for a short time, a primary has to support 2 divers and the inflation of the BCD or wetsuit.
Having a reg adjusted for a pony, slightly higher cracking pressure to minimize free flow is something else to consider.

I like using an older reg that I have retired from primary service, you pretty much know what you have at that point and the only issue to to use it on ocasion and do a regular checkup on the IP and cracking pressure. Its all too easy to skip all the service on a pony reg and have a nasty failure when you need it.

---------- Post added December 15th, 2012 at 12:40 PM ----------

I use a H2Odyssey RG2V - absolutely wonderful.

Piston First Stage - RG2V - Marine Scuba Gear Air Systems - Goodrum International

That intended for the really small bail out bottles, like the 6 cu ft on they sell. Its intended to be trans-filled from your primary bottle.

 

[beaverdivers]

It should be the best reg you own and definitely not one that's prone to free-flows.

I agree!

Also, I'd suggest a DIN connection on the reg and tank. When the brown stuff hits the fan, the last thing you want to discover is that instead of turning on your gas, you just unscrewed the yoke, It's too easy to confuse the knobs if you're not careful.

If your pony is ON, you won't be able to unscrew the yoke. However. I do agree that DIN may be your best bet.

However if you are travelling abroad, DIN tanks are not always available. If you have a malfunction with your primary 1st stage, then you may have lost your ability to use your backup DIN 1st stage to replace your down primary 1st stage. Of course, at that point you are down to just one reg. and no pony unless you rent one.

It would make life easier if the whole world were DIN!

 

[Kharon]

-------- Post added December 15th, 2012 at 12:40 PM ----------

Originally Posted by Kharon
I use a H2Odyssey RG2V - absolutely wonderful.

Piston First Stage - RG2V - Marine Scuba Gear Air Systems - Goodrum International



That intended for the really small bail out bottles, like the 6 cu ft on they sell. Its intended to be trans-filled from your primary bottle.

Definitely not so!

1st, it can be used on any size tank - 13, 19, 27, 30 - it's not limited to specific pony sizes. If you wanted to, it could be used on an 80 or bigger.

2nd, while it can be filled from another tank you won't get a full fill unless it's a very HP that you are filling from or you are filling a LP pony and use more than one 3000 psi. tank. It has a station filler available as well as the yoke filler. Unless I'm desperate, I get it filled at the shop to get a full 3000 psi.

 

[Jim Lapenta]

But why would you use it on an 80? For travel that is one of the last things I'd choose. Right after a Spare Air. It screws directly into a tank. Not an ideal choice. Are you using it with a hosed second? If so which one? If not then the second mounts directly to the first. That means you have to hold the bottle. I would not accept this as a possible redundant air source in my AOW class. If one is going to use a pony get a proper bottle and reg set up. First stage, 40 inch hose, second stage, spg on a 6 inch hose. I use HOG D-1 non colds on stages and pony bottles for shallower, warmer water and O2 bottles. D-1 colds on those that will see temps below 40 and under the ice.

 

[GrumpyOldGuy]

Definitely not so!

1st, it can be used on any size tank - 13, 19, 27, 30 - it's not limited to specific pony sizes. If you wanted to, it could be used on an 80 or bigger.

2nd, while it can be filled from another tank you won't get a full fill unless it's a very HP that you are filling from or you are filling a LP pony and use more than one 3000 psi. tank. It has a station filler available as well as the yoke filler. Unless I'm desperate, I get it filled at the shop to get a full 3000 psi.

It can be used on any tank, it just not a good match for the larger tanks. I have one, have used it many times, I also use a traditional reg on 2 other pony bottles and understand the pros and cons.

The idea behind integrating the valve and regulator is to save weight (assuming for travel). You also have a slightly simpler system (no yoke or din) connection. You can hook the 2nd direct to the 6cu ft bottle with a swivel (requiring a hand hold) or a hose.

That makes sense for a 6 or maybe a 13 on the outside. After that point, the reduction of travel weight is insignificant.

What you loose it the ease of filling. You have to purchase an adapter to fill at a station (more cost and something else to loose or break) and/or a trans-fill with another adapter (and end up with a 2800psi fill on both tanks). You also loose the ability to swap regs should your primary start to act up or swap pony bottles without draining both.

It a neat system, but like many non-standard systems once your use expands beyond the original niche the use of a standard system makes more sense.

 

[dpaustex]

I think people misunderstand the intent of the "pony reg". Each reg should be the same quality. As someone else stated, your main reg just failed....

If you're diving sidemounts, you have two independent setups, too. In cave diving, you take turns on each of these, breathing them down relatively equally (to your reserve, or "turn" pressure).

I, too, solo dive, but you need to understand that many incidents aren't just about OOA situations. With no buddy, their is no help for in-water issues that are not air-related.

 

[halocline]

If anything, I want my pony reg to be the most reliable reg I own. After all, the main reg just failed....

Or the tank valve failed, or the diver ran OOA due to not paying attention, or a hose blew, or another diver needs air for any of the above reasons...

I do agree that pony regs should be reliable, (like all regs should be) and flood tolerant, and cold water tolerant if necessary. The lowly MK2 or similar sherwood flow-by piston regs fit all these criteria in an almost ideal manner. Cold tolerance of these is far better than in flow-through pistons because the point of depressurization is shielded from the piston by the seat, and the orifice (which gets the brunt of the adiabatic cooling) is attached to the reg body and nowhere near the ambient chamber. In the flow-through (balanced) piston design like the MK5/10 etc....the piston edge itself gets the coldest and that can easily radiate up the shaft into the ambient chamber.

The other nice bit about this design is that there are no dynamic o-rings subjected to HP air, and as such flood tolerance is likely improved. (AFAIK nobody has done controlled experiments to positively determine this) The HP section on these regs is VERY simple, no balance chamber, no floating seat, etc...

The comments about 'the pony reg should be the highest quality' or similar are a little misleading because the implication is that the pony reg should be as expensive as the back gas regs. This is simply false; nobody needs ultra-balanced IP stability or ultra-high flow on a pony reg, and the MK2 provides significantly more air than any 2nd stage can flow regardless. Personally, I think that the unbalanced piston on the pony has another advantage; it will begin to breathe more stiffly as the tank nears empty. Under 500 PSI on a pony bottle means you've got a few more breaths, so having some warning you're nearing the end is not at all unwelcome.