Tank Equalizer for $2.50

[halocline]

Someone ask about something similar in another post and while thinking it over I came to the conclusion you really need either a second stage or relief valves on both ends for a couple of reasons (I am assuming you are dedicating a couple of old first stages for this). First off, how are you going to bleed off the pressure when you try to remove the regs? Secondly, if the regs are OK everything would be fine but what if the IP on one or both regs goes high? You could end up with HP side pressure on the LP side. This is surely going to blow out a diaphragm or piston Orings at a minimum if not something more dramatic. For safety’s sake, IMO some form of pressure relief is needed on both ends as well as a means of depressurizing the regs when the transfer is done.

You only need one 2nd stage on one reg to depressurize. When you depressurize one, both HP chambers empty because they're connected via the hose. What could happen, I suppose, is that IP could get "trapped" in the IP chamber of the reg with no 2nd stage, then the next time you loosen a port plug, you'll get a little air releasing. That has happened to me before, it just wasn't until now that I figured out why that 1st stage sitting in my drawer had some pressure in the IP chamber one day.

Regarding using a 2nd stage on both 1st stages in case of a HP seat failure/IP spike, it's not a bad idea, but on mine, if that were to happen, there would just be a massive leak at the piston head o-ring, at least I don't think that o-ring could handle 3000 PSI!

I use this set up with one 2nd stage all the time, but as I said, your suggestion of two for the protection of each 1st stage is not bad one at all.

 

[Flatliner]

This is a really great idea. Just ordered a fitting. It will work wonderfully to top off my pony bottle from my 121 when I use it to vaccuum the pool...

 

[Slamfire]

Dammit!!! Why is it that I get to see this thread only until today?!!! I rushed to the closest Acklands-Grainger (Canadian Grainger) which is only a few km's away from my office and we identified both adapters and I ordered two of each. They will have them in on Monday which is going to be too late for my upcoming dive trip.

*deep breath* No matter. The adapters will come in good time and I also managed to find a new source of orings. I placed an order Acklands-Grainger for 2 dozen 2-013 viton orings for the HP seats of my Mk10's and all these orings come at the exorbitant price of $1.46 cents. I'm not sure if these guys are making any profit after the postage.

Brother, couv, this is a simple, elegant solution... Kinda makes me feel bad I didn't think of something like this and was seriously entertaining the idea of getting a $170 dollar whip...

 

[Mitchell Teeters]

Necropost

I don't have any spare first stages and don't want to have to take apart mine. So I ordered two scuba fill stations off ebay @ $15 ea, I'll pick up some high pressure hose and make a quick trans-fill set up from that. I saw a guy doing it on youtube and think this would be a quick easy method of topping off my 19cf pony.

 

[The Chairman]

After someone actually does this, please post how quickly the tanks equalize. Most HP ports have only a tiny orifice that acts to inhibit voluminous loss of gas in case of an HP hose/oring failure.

 

[Mitchell Teeters]

NetDoc, after talking to a buddy that works in a scuba/paintball shop he stated that the method I'm going to use will be faster than a first/first setup. He said that the yokes I'm going to use are large orifice and the fills will be MUCH faster. He like the idea a lot and planned on doing one himself (or he led me to think). LOL

I just need something to top off a pony, or equalize tank to tank. I'm debating on whether to adapt a scuba high pressure hose (gage) or buy a braided hose from the local auto shop. I figure I will be told I will DIE if I use the steel braided hose.

 

[redacted]

Necropost

I don't have any spare first stages and don't want to have to take apart mine. So I ordered two scuba fill stations off ebay @ $15 ea, I'll pick up some high pressure hose and make a quick trans-fill set up from that. I saw a guy doing it on youtube and think this would be a quick easy method of topping off my 19cf pony.

The key is getting the right connection for the HP hose to fill station. I made my equalizer from two spare air fill yokes. A local hydraulic shop made the hose for me for about $40. The two connectors were a bit of an oddball thread size so they ran about $12 each.

 

[Slamfire]

After someone actually does this, please post how quickly the tanks equalize. Most HP ports have only a tiny orifice that acts to inhibit voluminous loss of gas in case of an HP hose/oring failure.

I've been using couv's $2.50 equalizer for the better part of a year now. I like it specifically because it is slow. Slow fills are good. Particularly when dealing with high O2 concentrations. I haven't timed it yet, but if I had to guesstimate I would say 5-10 mins. I deal with Al80's, Al50's, Al40's, LP108s doubles, LP77s doubles, Al80s doubles. I'll take time readings next time I transfill and post the results here.

I'm debating on whether to adapt a scuba high pressure hose (gage) or buy a braided hose from the local auto shop. I figure I will be told I will DIE if I use the steel braided hose.

I built my mixing whip using this hose which I got for $30 brand new. My fillers (CG540 for O2 and DIN) both have a female 1/4" npt. If your fillers dont have this thread size, Mcmaster-Carr has this same hose in several other sizes.

 

[cc.harley]

My KISS solution with things on hand

 

[Mitchell Teeters]

Fill stations arrived
$14.99 each
Hose
$33 (more than I expected)
Flushed the hose (6 k psi burst by the way)

Took 40 Secs to set up on tanks.

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