Cheap equalization hose

[Couv]

Hello All,

If one were a cheap bass turd and wanted to make a tank equalization device; would it be feasible to connect two first stages at the HP ports via a SPG HP hose with one end adapted from female to male? If so, this would be a very quick and easy and cheap method for the occasion of when one wants to VIP his own tank and then take it to the LDS for a fill and avoid the didactics regarding a VIP required due to an empty tank.

Tanks,

couv

 

[ReefHound]

Being a cheapo I looked into this route and decided it wasn't worth it. First stages are not designed for HP reverse flow and certainly not for the volume needed to cross fill. You can pick up a decent equalizer with spg from scubatoys for under $120. It'll take awhile to recoup that from VIPs but there are other uses for it as well. It can serve as a tank pressure checker and good to equalize tanks at a dive site, such as maybe you have 3000psi and your buddy got a low fill at 2400psi or less. And then there's the cool factor...

 

[battles2a5]

It would take FOREVER to equalize two tanks using an HP hose. Plus you would need another second stage or some sort of bleed valve to depressurize the system once they are equalized. I haven't seen the $120 unit on scubatoys, but you can pick up a good transfill whip for under $200 from several places (TDL, Salvo, etc.).

 

[Couv]

I am given to understand that the HP part of a regulator is just the metal block with a hole drilled to the HP port and all upstream of the piston, diaphragm or even the HP seat. Therefore, the low pressure side of the regulator would not even "know" where the pressure was coming from. Speed in filling is not the issue, just need a quick spurt. To bleed, simply press the purge on the second stage.

But I could be wrong….hurry up and go try it on your regulators before I do.

c

 

[redacted]

I made the mistake years ago of buying a couple pool toys (spare airs) but the fill adapters served as the basis of my equalized hoes. Local hydraulic shop found the fittings and built the hose for about $50. I think I have recouped the cost just in top-offs of my somewhat marginal 13df pony.

Check with your local hydraulic shop to see if they can replace the female end of an HP hose with a male connector. If you are like me, you probably have a good supply of worthless 32" to 36" long HP hoses. Topping off a pony or balancing 2 close tanks shouldn't take too much time. Filling a small pony or xfering 10+ cf might take a while but so do surface intervals.

I got curious so I just put one of those larger party balloons over the female end of an HP hose and connected it to a tank with 800 psi. It was toast in about 30 - 40 seconds. I'd estimate that was about 1/2+ cf of gas. Thinking about what will happen as the pressure differential falls is giving me a head ache and I don't have any tanks handy with less than 100 psi. But you might want to try that before you spend the $$$.

 

[ReefHound]

I'm not saying using first stages wouldn't work, I just don't know and decided not to experiment with mine. It would be *possible* to design seats, diaphragms, and o-rings such that they would be dislodged or damaged by HP flow in the reverse direction. Whether any first stages out there are this way, I don't know. In the end, I decided I will be diving at least another 20 years, God willing, and the equalizer will last a lifetime. The money has been spent and forgotten but at least I have something material to show for it, unlike all the money I've spent eating out at restaurants.

 

[Luis H]

Ok, the cheapest way to do this I have heard is just put the two yoke style tanks in front of each other with the valve opening touching. Hold the valves tight against each other. You can get fancy a put a rubber doughnut like a slice of hose between them. Open the empty valve and just ram some air into the empty tank. I have heard you can easily get enough air to pass LDS inspection.

I used to use an old twin tank adapter manifold. Sometime they show up on eBay, but the price has gone up to much.

The best is to make a cross over hose using two old pressure gauge tank checkers. Sometimes you see some on eBay at a reasonable price if the gauge is all busted and has no collectible value.

The hole on many first stages is too small to transfer any reasonable amount of air in a reasonable time. In some they are laser drilled to be the smallest possible. For what you are trying to do would be OK, but it sounds like too much trouble for a very limited use (IMO, it would take too long to really equalize two tanks).


Let me know how my first suggestion worked, after you try it.

 

[pir8]

Are you going to get your own VIP stickers printed?

 

[battles2a5]

I am given to understand that the HP part of a regulator is just the metal block with a hole drilled to the HP port and all upstream of the piston, diaphragm or even the HP seat. Therefore, the low pressure side of the regulator would not even "know" where the pressure was coming from. Speed in filling is not the issue, just need a quick spurt. To bleed, simply press the purge on the second stage.

But I could be wrong….hurry up and go try it on your regulators before I do.

c

You said you wanted to attach the two regs via a HP SPG hose. The orrifice in that hose is tiny. Do a search on the "cutting a divers hose" thread and watch the video that scubatoys made. Maybe if you had the fittings made for some HP filling stock to fit into the HP ports it might work, but it would be a kluge. I think the best way to go about this would be just buy or make a transfill whip. You can find the parts list on the internet if you want to save a few bucks.

 

[ReefHound]

Actually, he already found the cheapest way - borrow mine.