Tank Equalizer for $2.50

[raftingtigger]

I use 2 old 1st stages connected via the HP ports and a LP BC hose as my pressure relief. Works great.

 

[Couv]

I use 2 old 1st stages connected via the HP ports and a LP BC hose as my pressure relief. Works great.

Raftingtigger,

If I'm not mistaken, the valve in a low pressure inflator hose is an upstream valve (such as one on a tire and wheel assembly.) It opens against the flow of gas and closes in the direction of flow. Therefore, the pressure in the hose would continue to build until the hose burst.

 

[chrpai]

If I'm not mistaken, the valve in a low pressure inflator hose is an upstream valve (such as one on a tire and wheel assembly.) It opens against the flow of gas and closes in the direction of flow. Therefore, the pressure in the hose would continue to build until the hose burst.

I had to read this a couple times. I think what you are trying to tell him is that the LP inflator is good enough to be able to purge the system when you are done with the equalization but it's not good enough to protect from runaway IP creep. You'd need second stages or those over pressure gadgets they put on argon bottle regulators.

Is that what you mean to say?

 

[raftingtigger]

I had to read this a couple times. I think what you are trying to tell him is that the LP inflator is good enough to be able to purge the system when you are done with the equalization but it's not good enough to protect from runaway IP creep. You'd need second stages or those over pressure gadgets they put on argon bottle regulators.

Is that what you mean to say?

It is certainly good enough to purge the system. As for a runaway IP creep, The system isn't connected and pressurized for more than a minute if even that. Unlikely to have a catastrophic IP failure of that level. I guess I could install an old 2nd (I have them), but that makes the rig that much bulkier to pack.

I am interested in the likelihood of, and consequences of a IP leak catastrophic enough to cause a LP hose failure under the above conditions.

 

[chrpai]

I've never built one of these hacked equalizers. I would have assumed it would take more then a minute to transfer any sizable amount of gas due to the size of the passage in the HP hoses. Are you just transferring a couple hundred PSI to top off a tiny pony or something?

For something smaller look at:

Over Pressure Relief Valve - Northeast Scuba Supply

If a high pressure seat fails, the gas as to go somewhere. How likely? Well, I'm going to guess you dedicated a couple of "junk" regs to put this together on the cheap (nothing wrong with that) and that you don't spend money to service them every year. It's not a sure thing, but it could happen.

 

[rhwestfall]

one of the HOG quick shot bag inflators provides the bleed off point, and at "minimal" cost, and minor mass to the device. OPV might be a good idea too.

Chrpai: I'd reckon that most of the folks making/using one of these are DIY folks, and likely would be servicing the stages as necessary (and we know yearly isn't necessary).

 

[chrpai]

Perhaps, perhaps not. I'm not judging.... I'm a cheap arse at heart and was attracted to the "$2.50" headline. That said, I wouldn't want to use my main regs so my first inclination is to go on eBay and look for the cheapest junkers I can find.

I think the paintball adapters and HP hose setup for around $65 is the most practical solution. I have a hard time spending $150 for a "proper" setup.

 

[uncfnp]

Perhaps, perhaps not. I'm not judging.... I'm a cheap arse at heart and was attracted to the "$2.50" headline. That said, I wouldn't want to use my main regs so my first inclination is to go on eBay and look for the cheapest junkers I can find.

Got the Grainger fitting (turned out they had a branch location 8 miles up the road!). Haven't needed to use it yet but curious about your concern for the regulators. How is using the regulator to equalize pressure between tanks different from using it on the same tank, exposed to the same pressures each time you dive? Is there a reason hooking it up to transfer air through the HP ports will increase the risk of damage? Understand, I am very much a beginner in this DIY stuff! Still lots to learn. Thanks.

 

[Mitchell Teeters]

If you are cheap the paintball filler yokes work great. They already have gauges as well.


Sent from my iPad using Tapatalk

 

[Couv]

Perhaps this thread has gotten too long in the tooth so I'll try to summarize the reason I started it.

......The intent: to transfer just a few cubic feet of air from one bottle to another...

...Herman points out, ANYTIME you install a regulator on a tank there MUST be some form of protection in case of runaway IP. . Usually that protection is provided by the second stage.

....I assumed most of you wanting to use this technique would use two fully functioning regulators-including a second stage attached to each first stage-

...The $2.50 fitting is just a very small addition to your Save-a-Dive kit; it's not intended to replace a cascade system. ...If you need a fill whip-get one.

Cheers,

Couv ....

Is that what you mean to say?

In response to:

... a LP BC hose as my pressure relief. Works great.

I should have said the low pressure hose will not act as an over pressure relief valve-unless one considers a blown hose a safety device.

....I wouldn't want to use my main regs ....

Please explain why.

I think the paintball adapters and HP hose setup for around $65 is the most practical solution. I have a hard time spending $150 for a "proper" setup.

OK, my method takes about 15 minutes (20 minutes including the set up time) to equalize a set of 80 cu ft tanks. The fitting weighs about 50 grams and takes up about 1.5 inches of a spare parts kit and cost $2.50. But time is money, so if you don't have 20 minutes to spare or have a lot of tanks to fill/transfer use one of the $65 or $90 or $150 bulky devices.

Is there a reason hooking it up to transfer air through the HP ports will increase the risk of damage?..

No....but with all the resistance to using this simple, inexpensive method, I would appreciate the input of someone who has found reason not to use it for the purpose I've described.