Equalizing tank pressure at depth

[traumadiver]

Imagine this scenario for a second. You and your buddy are at 40' having a wonderful dive seeing the little fishies swim around. Your buddy has lost situational awareness and stopped checking thier SPG. When your buddy does finally check it, the diver realizes that the fish are not so important anymore because they are critically low on air. Your buddy wide eyed and bushy tailed signals to you that it is time to go topside. You being the super diver you are have been keeping track of your air consumption and find you have alot of air left in your tank. Keeping your buddy calm you whip out a hose that is hooked up to your 1st stage and connect it to a device that is hooked up to thier 1st stage. You having the higher tank pressure, are now able to donate your air to your buddies tank, equalizing both tanks. You now have more dive time, or at least more time to avert an out of air emergency.
In the typical out of air scenario, you remain attached to your buddy for the most part via an octo. This device would eliminate that.
This scenario is played out on the surface many times in the fire service. As most know firefighters use Self Contained Breathing Apparatus or SCBA. One of the features is the ability to equalize air tanks using a hose. Once the tanks are equalized, you disconnect the hose and keep working.
I understand that there may be an issue with over-pressurization of your tank since the air you donate to your buddies tank will expand as you ascend. However, if your buddy is at less that 1000psi or some other magic number what do you think the dangers would be?
I am not sure if this is really a good idea or not. I am just looking for some input.

 

[Blackwood]

the air you donate to your buddies tank will expand as you ascend.

No it wouldn't.

Honestly, I think this is a solution in need of a problem. What does your buddy breathe as you are connecting the fill whip? Probably gas you're donating via a regulator. So what's the need to donate tank-to-tank? Not to mention the likelihood of injecting water into their tank.

 

[JBRES1]

All that comes to mind is, how are you going to make a dry connection between the 2 hoses. You could force high pressure water into the reg with the lower pressure.

Also, you would be needing to have 2 high pressure ports on your regs, and some regs only have 1.

Jim Breslin

 

[Kern]

Imagine this scenario for a second. You and your buddy are at 40' having a wonderful dive seeing the little fishies swim around. Your buddy has lost situational awareness and stopped checking thier SPG. When your buddy does finally check it, the diver realizes that the fish are not so important anymore because they are critically low on air. Your buddy wide eyed and bushy tailed signals to you that it is time to go topside. You being the super diver you are have been keeping track of your air consumption and find you have alot of air left in your tank. Keeping your buddy calm you whip out a hose that is hooked up to your 1st stage and connect it to a device that is hooked up to thier 1st stage. You having the higher tank pressure, are now able to donate your air to your buddies tank, equalizing both tanks. You now have more dive time, or at least more time to avert an out of air emergency.
In the typical out of air scenario, you remain attached to your buddy for the most part via an octo. This device would eliminate that.
This scenario is played out on the surface many times in the fire service. As most know firefighters use Self Contained Breathing Apparatus or SCBA. One of the features is the ability to equalize air tanks using a hose. Once the tanks are equalized, you disconnect the hose and keep working.
I understand that there may be an issue with over-pressurization of your tank since the air you donate to your buddies tank will expand as you ascend. However, if your buddy is at less that 1000psi or some other magic number what do you think the dangers would be?
I am not sure if this is really a good idea or not. I am just looking for some input.

There are whips you can get to equalise 2 tanks. You could even do this underwater. You would however need a third tank to breath off while you equalised the other 2 tanks. It's a stupid idea. Also, doing this underwater will put some salt water into the tank, this isn't a good idea. If your buddy gets low on gas or go's OOG its time to call the dive & head for the surface before something else can go wrong.

Your scuba tanks are made of rigid materials, as you ascend there will be no change in the tanks pressure due to the change in ambient pressure.

 

[herman]

Lot of other problems as well. HP ports on regs have a very small hole in them, ever notice how slow a HP gauge builds pressure? Pull a HP hose off and look at the hole in the reg, the hole in modern regs is almost too small to see. This is to prevent rapid loss of air if a HP hose ruptures. It would take hours to equalize tanks via a HP port. Besides, the moron has already went OOA once, do you really want to give them a second chance on the same dive. Octos work fine.

 

[redacted]

My buddy and I balance our air supply whenever it is necessary. Well before even getting close to a LOA (usually when lower tank is 1000 psi) she goes on my long hosed primary and we continue the dive just a little closer than usual. When I hit 1000psi, we each go back to our own gas and finish the dive.

 

[traumadiver]

Okay, well I can see that this idea was not a very good one. Although it works on the surface in dry conditions I can see how doing this underwater using SCUBA gear would be a major problem.
Thanks for reading the post and commenting. So much for my million dollar idea! hahahaha!

 

[Cave Diver]

Okay, well I can see that this idea was not a very good one. Although it works on the surface in dry conditions I can see how doing this underwater using SCUBA gear would be a major problem.
Thanks for reading the post and commenting. So much for my million dollar idea! hahahaha!

While this idea may not be practical, dont let that discourage you from thinking of others. Never know when you might find the one!

 

[shawrg]

Okay, well I can see that this idea was not a very good one. Although it works on the surface in dry conditions I can see how doing this underwater using SCUBA gear would be a major problem.
Thanks for reading the post and commenting. So much for my million dollar idea! hahahaha!

Don't be so hasty with your surrender. Most truly great ideas are originally ridiculed. Yet the truly great inventors always finds a way. Now I'm not saying this is one of those great ideas, I'm just saying don't give up on something you really believe in. There are applications other than recreational scuba diving to consider. Besides, to have a desirable product and thus make mega$, you only need to have Billy Mays endorse it on tv !

 

[rsilva708]

A transfill underwater was something I was looking at for my world record attempt. It can be done, but does have some risks involved.