darylm74
Contributor
What size pony are you using for Argon or extra air for that matter to use for a Drysuit?
Tank Size for Argon for Drysuit
- Thread starter darylm74
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Two VERY different questions. Unless it is one very strange question--you wouldn't use a pony for air FOR the drysuit when you already have plenty of that on your back!
Which of the 3 questions are you asking:
Size of pony for argon for suit?
Size of pony for air (or other gas) to breathe?
Size of pony for air for suit!?
theskull
Which of the 3 questions are you asking:
Size of pony for argon for suit?
Size of pony for air (or other gas) to breathe?
Size of pony for air for suit!?
theskull
It depends on a lot of factors, like whether you have a boost pump or are transfilling, how deep you are diving, how many dives per day/trip you plan to make, etc.
If you transfill, a low pressue (2015 psi) pony makes more sense as you will get a better proportion of a fill at less than full supply tank presures. Argon is normally only available at around 2200 psi, so without access to a boost pump, a 3000 psi tank will only hold 2/3 it's capacity when transfilled from a newly filled tank and will be down to 1/3 it's capacity as your argon supply tank drops to around half full at around 1000 psi.
If you do one or two dives per day, you can get by with a smaller tank but if you are doing multiple dives per day over multiple days, you need a larger pony or more than one pony. In a pinch you can top off your argon tank with air to get you through a day or trip, but this further compromises the already limited insulating properties of the argon as the fraction of air in the mix increases.
Shallow dives obviously require less argon than deeper dives.
My preference (when I believed in using argon) was a 15 cu ft 2015 psi AL pony. It was adequate for several dives even when only filled to around 1000 psi.
If you transfill, a low pressue (2015 psi) pony makes more sense as you will get a better proportion of a fill at less than full supply tank presures. Argon is normally only available at around 2200 psi, so without access to a boost pump, a 3000 psi tank will only hold 2/3 it's capacity when transfilled from a newly filled tank and will be down to 1/3 it's capacity as your argon supply tank drops to around half full at around 1000 psi.
If you do one or two dives per day, you can get by with a smaller tank but if you are doing multiple dives per day over multiple days, you need a larger pony or more than one pony. In a pinch you can top off your argon tank with air to get you through a day or trip, but this further compromises the already limited insulating properties of the argon as the fraction of air in the mix increases.
Shallow dives obviously require less argon than deeper dives.
My preference (when I believed in using argon) was a 15 cu ft 2015 psi AL pony. It was adequate for several dives even when only filled to around 1000 psi.
6 cfdarylm74:
When full, it's good for 3-6 dives depending on depth.
For Argon to be effective, I find I need to pre-purge the suit (from another tank if possible), otherwise the air already in the suit so dilutes the small amount of Argon I use that there's virtually no benefit.
OP
darylm74
Contributor
theskull:
I am looking at a pony to supply either air or argon to the drysuit. My primary reason for this is I have a conshelf XII that I want to start diving that only has 3 LP's, meaning I'm missing one for my drysuit. I wanted to buy a pony to supply either air or argon for the drysuit. So I guess the question would be, what size do I need for the drysuit and would the size be different depending on whether I use air or argon. Sorry for the confusion.
I use air quite often as my alternate inflator gas. It is much cheaper than argon and unless one is purging their suit prior to the dive to flush out the air anyway, the diver adding argon to their suit at depth is mixing it w/air and getting very little benefit from the argon itself. If one is using a helium based mix on their back, it's not the best idea to connect up back gas for drysuit inflation. The diver will chill rapidly, even in water one would otherwise consider "warm". I am assuming this is what the original poster was referring to when they mentioned using "air in the pony". I personally have not noticed that great of a difference between argon and air, but this is subjective and ymmv. My dives are at the most, only 90 minutes in the cold deep stuff, some of the shallow dives are in the 2hr range, but the temp is much warmer. I know some will do longer dives and claim the argon is noticeable....like I said, ymmv.theskull:
I (and most other mix divers I know and dive with) use a 6cf luxfer aluminum (3000psi) bottle. I have used the 2014 psi/14cf aluminum luxfer as well, hooked up to the left side of my twins via velcro straps. It is a bit overkill for what we do. The 6cf bottle will last for ~4 dives to 200' or 6-8 recreational depth dives. Currently, that is what I use on wreck or cave dives. It is small, simple, and works great.
dive safe!---b.
The volume requirements are the same for air or argon. The difference would be that you could always obtain a full 3000 psi fill with air in a 3000 psi pony while you won't be able to get a full 3000 psi fill with argon in most cases unless you or your LDS has a boost pump dedicated to argon use.
As snowbear indicates, a FULL 6 cu ft tank is good for 3-6 dives depending on depth. But it follows that if you can only transfill 1000 psi into a 3000 psi 6 cu ft pony, then you have 1 to maybe 2 dives at most. So unless you can obtain full argon fills for a smaller pony, a larger one may be required.
Another issue to consider is the need to purge the suit to remove as much air as possible and replace it with argon prior to the first dive. If you keep the suit on between dives, you can get by just doing this before the first dive. If you remove the suit during the surface interval, you will have to repeat it and the argon required for the days dives increases.
If you have a conshelf XII, my suggestion would be to use it for your argon reg and find a more suitable first stage with 4 ports for your primary reg since you are going to need 2 first stages anyway.
This will allow you to run another dry suit inflation hose off the primary reg. That in turn will allow you to only use argon on dives where you need it and will also allow you to switch hoses mid dive to finish inflating your suit with air if your small pony runs out during the dive.
Another option would be to locate one of the little adapters to add 2 more ports to your older 3 Lp port reg. They screw into one of your LP ports and then provide 3 ports that you can attach LP hoses to (so you actually gain 2 ports). They used to be a very common if less than elegant solution to the problem.
As snowbear indicates, a FULL 6 cu ft tank is good for 3-6 dives depending on depth. But it follows that if you can only transfill 1000 psi into a 3000 psi 6 cu ft pony, then you have 1 to maybe 2 dives at most. So unless you can obtain full argon fills for a smaller pony, a larger one may be required.
Another issue to consider is the need to purge the suit to remove as much air as possible and replace it with argon prior to the first dive. If you keep the suit on between dives, you can get by just doing this before the first dive. If you remove the suit during the surface interval, you will have to repeat it and the argon required for the days dives increases.
If you have a conshelf XII, my suggestion would be to use it for your argon reg and find a more suitable first stage with 4 ports for your primary reg since you are going to need 2 first stages anyway.
This will allow you to run another dry suit inflation hose off the primary reg. That in turn will allow you to only use argon on dives where you need it and will also allow you to switch hoses mid dive to finish inflating your suit with air if your small pony runs out during the dive.
Another option would be to locate one of the little adapters to add 2 more ports to your older 3 Lp port reg. They screw into one of your LP ports and then provide 3 ports that you can attach LP hoses to (so you actually gain 2 ports). They used to be a very common if less than elegant solution to the problem.
I think why we're confused is your use of the word "pony". "Pony" imples a breathable cylinder of air/Nitrox with a first and second stage regulator that's used in case of emergency to allow a diver to self-rescue in an out-of-air situation. You'd never put argon in a pony for this reason, because it's not a breathable gas. It's like asking "What kind of drinking container would you suggest I get for Gatorade and Gasolene?" -- it caused us all to go "Huh?"darylm74:
My guess is that your're simply asking for a recommendation of a cylinder/tank size to use for supplying argon (or air) to the suit, period.
Is this correct?
Roak
Ps. There are LP splitters available that will allow you to connect two LP hoses to one port, have you considered that?
OP
darylm74
Contributor
I wasn't aware of the splitters and that is an option if I can find one. I was not aware that they were out there or was worried about drop in pressure due to splitting the two. I guess it would be best to split the drysuit and BCD since I wouldn't be inflating both at the same time. Sorry for the confusion about the world "Pony" I heard that term used in welding and other areas that use cylinders for any smaller than normal tank. I guess I just didn't think to differentiate in this occurence.
Thanks for all the input.
Thanks for all the input.
boomx5
Contributor
As others have a stated, I also use a 6cuft bottle for my drysuit.
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