pony reg?

[rsingler]

I believe my comment stands: a flooded piston will recover where a flooded diaphragm may not.

 

[lowviz]

I'm not intending to stir the pot, but I consider this germane to the discussion:
Made In China

 

[Schwob]

I believe my comment stands: a flooded piston will recover where a flooded diaphragm may not.

OK, I'll bite.
Presuming I leave the first stage on the pony tank for the entire dive, what exactly would I need to do to flood a regulator in general or a regulator on a pony specifically?

 

[rsingler]

OK, I'll bite.
Presuming I leave the first stage on the pony tank for the entire dive, what exactly would I need to do to flood a regulator in general or a regulator on a pony specifically?

It depends upon your technique. Most people pressurize their system and then shut it down. During your dive, if your purge button gets accidentally pressed, the system pressure may go to zero and water may enter your second stage hose due to increased ambient pressure as you descend. Depending upon dive position it may track to your first stage.
Alternately, there was a recent thread in which a diver had his pony flood from the tank /1st stage connection due to an O-ring leak, and flood from there.

Me, I try to avoid this problem by adding an in-line shutoff switch at the second stage. I leave the system pressurized the whole time. Yes, the switch is an additional failure point, but I prefer that to the risk of flooding my emergency air source.

 

[Schwob]

It depends upon your technique. Most people pressurize their system and then shut it down. During your dive, if your purge button gets accidentally pressed, the system pressure may go to zero and water may enter your second stage hose due to increased ambient pressure as you descend. Depending upon dive position it may track to your first stage.
Alternately, there was a recent thread in which a driver had his pony flood from the tank /1st stage connection due to an O-ring leak, and flood from there.

Me, I try to avoid this problem by adding an on off switch at the second stage. I leave the system pressurized the whole time. Yes, the switch is an additional failure point, but I prefer that to the risk of flooding my emergency air source.

Thanks. Haven't thought of it that way yet.

 

[stuartv]

If it's a pony bottle, I would leave it pressurized and ready to use at all times, so no risk of flooding the 1st stage.

If it's a deco bottle, I leave it pressurized and turned off until I ascend to the depth where I want to use it. I also tend to turn it on and back off just after I get in the water, just in case it accidentally purged when I splashed.

One is for emergencies. The other is for use at a carefully pre-planned time and a hazard if used at any other time.

Different purposes. Different handling.

 

[stuartv]

Also, in the "different purposes" vein.

Pony bottle: Emergency use only (barring practice). Only intended to get you straight to the surface (i.e. no deco stops - only a safety stop). Thus, not intended to ever be breathed all the way down. Not intended to use in any kind of overhead environment. Only has to feed 1 diver - no octo and no BC inflator. For this purpose, a non-balanced, flow-through piston 1st stage, with no swivel turret seems like it would be perfectly adequate, when paired with a balanced 2nd stage.

Deoco bottle: Planned to be used on every deco dive. Planned to use for potentially long amounts of time. Thus, a swivel turret that gives better and more comfortable hose routing would be more desirable. Planned to possibly use at depths deeper than recreational limits. Lost gas contingency planning means plans that would possibly result in intentionally breathing it down to empty or nearly so. Thus, a balanced reg with a swivel turret (whether it's piston or diaphragm) seems most desirable.

Of course, a reg set for a deco bottle should be excellent to also use as a pony bottle reg. But, if the purpose is really for use as a pony reg, it seems to me like there really is no reason to spend the extra - unless you have long-term plans to move onto tech diving. And even if you do, an O2 Clean reg set that is best used only at shallower (i.e. recreational) depths is still something you'll have good use for - i.e. your O2 or 80% or other final deco gas of choice. Having a swivel turret for a deco reg is nice (I guess), but certainly not a requirement. My only deco reg is a Hollis HO2, which does not have a swivel turret.

 

[gcarter]

I personally would not put any reg on a pony or stage that I would not be willing to breathe or rely on as my primary.

 

[stuartv]

I am in the process of replacing my primary regs with ScubaPro Mk 25 EVO/G260 sets.

I definitely do not feel a requirement to spend that same money to have Mk 25 EVO/G260 sets for my deco bottles.

My Hollis HO2 deco reg is dirt simple. A design very much like the ScubaPro Mk2. A non-balanced, flow-by piston. I wouldn't breathe it as my primary. But, the only real nit I pick with it as a deco reg is that it doesn't have a swivel turret, so the hose routing is always a compromise.

 

[T.C.]

I personally would not put any reg on a pony or stage that I would not be willing to breathe or rely on as my primary.

Concur. I carry the exact same reg on my pony as my primary.
The upside of this is that if your primary malfunctions before a dive, you can install the pony reg and the octo/gauge, and complete your dive, if you're comfortable with the risk of not having the pony that dive.