transferring scuba regulator from tank to tank underwater?

[Scared Silly]

The responses from some are just silly ... good thing folks learn to dive on the internet.

What a question for an instructor to ask....the real answer would be:
"it's a BS scenario because A) I would not have an empty tank under any circumstances other than reg/valve failure, and B) please tell me exactly what kind of reg failure would make it impossible for me to get air out of a tank."

FAIL - This scenario does and has happened so it is not BS. The goal for diving is not just going on the dive but learning how to come back from the dive alive. As a Divemaster you should have better knowledge.

I belive it could possibley be done, however the risk of rusting the interior of the first stage exsists..

FAIL - Brass which the vast majority of reg are made from does not rust it corrodes. Short term exposure to water will not hurt the reg.

Assuming you have another tank to breathe from, it might be possible to unscrew the SPG from the good reg, stick the SPG HP hose in your mouth, and blow air into it while you (quickly) switch regs. I dunno...

FAIL - Do you carry a wrench to disassemble your reg while diving?

If you keep the inlet pointed downward and don't descend, The 1st stage will trap gas and minimize water intrusion. Then, with the valve pointed upwards, open the valve on the good tank just a bit to displace water from the valve as the good 1st stage is installed.

Possible solution but it depends on a number of factors. For instance, some regs such as Atomic the second stage poppet releases when there is no pressure on it. Thus air and water can freely move through. As such, if the second stage was above the first stage this would not work.


But in reality and as I learned, I really do not give a damn about water incursion into a reg if the scenario dictates that I need to switch regs between cylinders in order to survive the dive. The reg will work just fine - it is not like water even salt water will corrode a reg so fast that the reg will fail to work.

Next time you are going to get your reg overhauled go throw it in a pool. Then throw a cylinder in. Dive down assemble it and then sit there and breath off of it till the cylinder is about empty - probably take ya a good couple of hours. Then hand the reg to your tech and have them immediately disassemble it. Other than perhaps some water still inside I doubt you will see anything.

 

[redacted]

Possible solution but it depends on a number of factors. For instance, some regs such as Atomic the second stage poppet releases when there is no pressure on it. Thus air and water can freely move through. As such, if the second stage was above the first stage this would not work.


But in reality and as I learned, I really do not give a damn about water incursion into a reg if the scenario dictates that I need to switch regs between cylinders in order to survive the dive. The reg will work just fine - it is not like water even salt water will corrode a reg so fast that the reg will fail to work.

Next time you are going to get your reg overhauled go throw it in a pool. Then throw a cylinder in. Dive down assemble it and then sit there and breath off of it till the cylinder is about empty - probably take ya a good couple of hours. Then hand the reg to your tech and have them immediately disassemble it. Other than perhaps some water still inside I doubt you will see anything.

I see this as primarily an academic issue for recreational divers but still worthwhile in developing an understanding of how your gear works.

Reg with a seat saver feature would only be a special problem if the 2nd stage were above the 1st stage allowing gas to escape through the 2nd and thus enter through the 1st. Any water that enters the 2nd stage and hose while lower than the first would not compromise the gas pocket in the first and be blown out later.

And I do agree that, in an emergency, water in the first stage will have no immediate
performance impact and most problems it might cause can be easily dealt with later. One exception, which makes the pool play a bad idea, is that water in the HP section of the 1st stage is likely to be driven into the SPG bourdon tube where it is just about impossible to remove. This tube is usually copper and may, in time be damaged by corrosion which would effect accuracy. Probably little or no problem for a single exposure of FW but the effects would be cumulative. SW exposure is probably more serious and each subsequent exposure, even to FW, would redissolve the salt and allow their corrosive effects.

 

[DCBC]

I am a Divemaster and a friend of mine who is an Instructor asked me how would you transfer a scuba regulator from one tank to another underwater, if one tank was out of air(but has a good reg) and the other tanks regulator had malfunctioned (second stage and octo but tank is full) without flooding the reg?,

Yes, of course you could change regulators; although you could just breathe off the valve (another skill-set that has been discarded over the years by certification agencies). :mooner:

 

[Scared Silly]

AWAP, you are right about the HP gauge I should have been clearer. Kids when trying the above pool practice take all unnecessary gauges and hoses off - leaving only the first stage and a single second stage - do not forget to plug all the empty ports .

 

[fppf]

Don't worry about your wireless transmitter. It has a stainless body with a stainless sensing diaphragm.

 

[doc8425]

Agreed. A small amount of water will enter the first stage & most of it can be blown out as described. If in a life or death emergency (a gas supply issue can be life or death), the regulator, if in good shape should be fine for the duration of the dive, even with getting a little water in it The diver then had I would just get BOTH regulators serviced ASAP afterward.

Agreed! In a life-or-death bind, I'll opt to get the regs serviced afterwards.

 

[bwi_diver]

All I know is back in 1973 when my wife and I got our basic (NASDS) certification, one of the exercises we did in the pool was to change a regulator on and off a tank while buddy breathing.
Glad it was a rental regulator. We got our own regulators before our checkout dive.

 

[tarponchik]

FAIL - Brass which the vast majority of reg are made from does not rust it corrodes. Short term exposure to water will not hurt the reg.

When I was training our instructor specifically told us to be careful when blowing air at the reg cap after dive so no air flow gets into the reg opening, since this can force some sea water into the reg.

I wonder what are regs galvanized with? Nickel? If there are brass parts inside the reg then salt water can possibly cause trouble quickly (copper in brass+nickel=galvanic pair=>accelerated corrosion).

 

[halocline]

T
FAIL - This scenario does and has happened so it is not BS. The goal for diving is not just going on the dive but learning how to come back from the dive alive. As a Divemaster you should have better knowledge.

No offense, but please tell me exactly how you would end up in a situation where you had a full tank that you could not get air from due to the regulator failing, AND a completely empty tank, AND have nothing else to breathe to get to the surface. Did you think about that one, what is this mythical diver breathing while switching the reg?

If the point of the scenario is to just discuss the technique of taking a reg off one tank and putting it on another under water, fine, just ask that. But if the scenario is to discuss how to dive safely and "come back from the dive alive" then it's a stupid question, because the real answer is you would never be in that situation, and you could easily explain how to dive in a manner that would prevent it. That's what safe diving is. What happened first, the reg failure that somehow, unlike 99.9999% of all other reg failures, resulted in total loss of gas flow, or the completely empty tank? If it was the reg failure, why wasn't the dive aborted immediately? If it was the completely empty tank, why isn't the diver breathing off his/her buddy's tank on the way to the surface?

You're watching too many Maguyver episodes, dude. Next time you might consider the facts before telling me what kind of knowledge I should have.

 

[fppf]

I think in my first post I told of a friend that had this happen.
He was doing a technical dive, with a lot of deco. When he made it to his 20 foot stop and turned on the O2 the O-ring on the DIN fitting blew out.

Now, he could have done his deco on back gas, however when your in 40 degree water and you have an hour of deco on back gas, you prefer not to do that. Switching the regs from is 50% cylinder onto the O2 cylinder was a good option. It allowed him to deco in a timely manor and get out of the water.

Would a recreational diver ever run into this situation, no.