Free flowing regulators... how much air loss?

[M DeM]

hi there-

Never had a free flowing reg problem that wasn’t fixed by turning it upside down, but I got to thinking..

How much air is lost with a free flow? Say i’m At 60’ and my reg starts to free-flow with, say, 800psi in the tank.

How long can I take to ascend? Is there even a “standard” rate it comes out or does depth/pressure add a variable?

Oh, hey.. say I’m breathing off a free flow... can I try to use my palm to cover the reg every so often if I’m worried about losing air?

 

[CuzzA]

hi there-

Never had a free flowing reg problem that wasn’t fixed by turning it upside down, but I got to thinking..

How much air is lost with a free flow? Say i’m At 60’ and my reg starts to free-flow with, say, 800psi in the tank.

How long can I take to ascend? Is there even a “standard” rate it comes out or does depth/pressure add a variable?

Oh, hey.. say I’m breathing off a free flow... can I try to use my palm to cover the reg every so often if I’m worried about losing air?

Kink the hose, just like a garden hose. If the failure is in the first stage it will only buy you time before the octo starts flowing. If it's just the primary reg that failed, you could easily end your dive without risk of running out of gas before you get to the surface.

There's a good video that tests the time it would take to lose all your gas from various failures. Let me see if I can find it.

 

[CuzzA]

Here you go...

Life Ending Seconds • ADVANCED DIVER MAGAZINE • By Curt Bowen

 

[cerich]

totally depends on the freeflow. If a complete first stage HP seat failure, think not long at all, if a partial failure could be not much. Same with a freeze up causing the free flow.

 

[2airishuman]

hi there-

Never had a free flowing reg problem that wasn’t fixed by turning it upside down, but I got to thinking..

How much air is lost with a free flow? Say i’m At 60’ and my reg starts to free-flow with, say, 800psi in the tank.

How long can I take to ascend? Is there even a “standard” rate it comes out or does depth/pressure add a variable?

Depending on the reason for the freeflow, you may have very little time at all, perhaps less than half a minute.

What you can/should do about it depends on the situation and your comfort underwater. I believe that most open water courses teach people that they should thumb the dive and ascend with their buddy while sipping air, and follow usual OOA procedures if necessary. I think that's good advice in most cases.

Some people might try feathering the valve, if they can reach it. Some people might try to diagnose the reason for the freeflow. For example, some second-stage freeflows can be caused by foreign objects or sand stuck in front of the diaphragm or in the purge button.

The fact that freeflows occur is one of the main reasons solo divers carry redundant air.

In cold water, if freeflows caused by ice are anticipated, some divers carry redundant air and are prepared to shut the valve on their primary air in the event of a freeflow. In many cases the reg will thaw after a minute or two, and the dive can be continued.

Oh, hey.. say I’m breathing off a free flow... can I try to use my palm to cover the reg every so often if I’m worried about losing air?

It usually won't work, and can cause the mouthpiece to come off.

 

[John Bantin]

Take a full tank and open the valve and time how long it takes to empty.

 

[mmerriman]

padi requires a free flowing regulator skill in confined water for open water class. I have observed 500-800 PSI loss in 30 seconds (in 4 ft or water). So - full tank at a very shallow depth will be empty in just a few minutes