Freeflowing Reg

[Morpheus]

I was diving the weekend... normal 35ft 80 water. i took the regulator out of my mouth for a second and it started freeflowing.I put it back in my mouth and it breathed regularly,i was concerned so I took it out again...freeflow again. Im sure this isnt normal. I turned it upside down and it did stop each time. what would cause this?

 

[murphdivers286]

1st question. What reg are you using?

I have a B2 which is very sensitive to pressure. It will freeflow if I drop it in the water while I'm on the surface, but if I turn it over for a second it stops. Even if it turns back facing up, it does not freeflow.

2nd question. Does you reg have an adjustment knob. Some regs have an adjustment knob that is more of a predive and dive knob than anything else.

I hope this helps a little. Maybe someone with more experience with regs can give you more information.

 

[MikeFerrara]

I was diving the weekend... normal 35ft 80 water. i took the regulator out of my mouth for a second and it started freeflowing.I put it back in my mouth and it breathed regularly,i was concerned so I took it out again...freeflow again. Im sure this isnt normal. I turned it upside down and it did stop each time. what would cause this?

Point it down when you take it out of your mouth and it probably won't free flow. From your description it sounds completely normal.

When the reg is pointing up there is enough pressure drop accross the diaphragm to depress it activating the valve.

Try this...

Put your reg on a tank.
With the mouthpiece pointing up slowly lower the reg into a bucket of water and see how low it getts before the valve opens...about an inch maybe? You just measured the pressure it takes open the second stage.

also...if you remove the reg from your mouth and slowly let it fill with water before pointing the mouthpiece up it probably won't free flow. That's because with water on both sides of the diaphragm the pressure is about equal.

 

[Morpheus]

Im using the Atomics T1x

 

[MikeFerrara]

Im using the Atomics T1x

It don't matter. While the pressure required will be a little different from reg to reg, if a couple inches WC isn't enough to open the valve it'll breath like junk.

 

[rescuediver009]

This is normal, if you open the adjustment knob and venturi all the way on the surface, and hit the purge it will also likely freeflow. It is a characteristic of most performance regs such as the Tx1. Is a good indication of how well your reg is working.

 

[Marek K]

OK, at the risk of getting just a little bit off-topic... I understand why a regulator free-flows... it's because of the pressure difference between the diaphragm and mouthpiece, cause by even the couple inches of depth difference when the mouthpiece is pointed up.

But why (in contrast to Morpheus) have just about all of my free-flows happened on the surface? Since water pressure increases linearly, the delta-pressure should always be the same at all depths.

My guess is that, on the surface, free-flows usually get started when the reg is dropped into the water diaphragm-down -- the smack against the surface pops the valve open, and it just goes from there. Yes?

--Marek

 

[Lemonade]

OK, at the risk of getting just a little bit off-topic... I understand why a regulator free-flows... it's because of the pressure difference between the diaphragm and mouthpiece, cause by even the couple inches of depth difference when the mouthpiece is pointed up.

But why (in contrast to Morpheus) have just about all of my free-flows happened on the surface? Since water pressure increases linearly, the delta-pressure should always be the same at all depths.

My guess is that, on the surface, free-flows usually get started when the reg is dropped into the water diaphragm-down -- the smack against the surface pops the valve open, and it just goes from there. Yes?

--Marek

On surface you have water on one side of the diaphragm, air - on the other, the difference in pressure of water vs. air is what pops it open. In contrast if you fill you reg with water and submerge it even with diaphragm down it should not open, since the delta is negligible.

 

[Marek K]

OK, I see what you're saying (I think)... the two inches of air are still practically at 1 atm; while the water two inches down would be at significantly higher pressure. (My rough estimate is that the difference would be just over one ounce per sq in... does that sound right? Enough to pop the diaphragm?)

I just seem to remember that everytime I've had a surface free-flow, it was after dropping the reg into the water for some reason...

And it also seems to make sense now that in a flooded reg, there should be no measurable difference in water pressure just above the diaphragm (inside the housing) versus outside -- assuming water can move freely in and out of the housing. So why would regs free-flow at depth?

--Marek

On surface you have water on one side of the diaphragm, air - on the other, the difference in pressure of water vs. air is what pops it open. In contrast if you fill you reg with water and submerge it even with diaphragm down it should not open, since the delta is negligible.

 

[murphdivers286]

OK, at the risk of getting just a little bit off-topic... I understand why a regulator free-flows... it's because of the pressure difference between the diaphragm and mouthpiece, cause by even the couple inches of depth difference when the mouthpiece is pointed up.

But why (in contrast to Morpheus) have just about all of my free-flows happened on the surface? Since water pressure increases linearly, the delta-pressure should always be the same at all depths.

My guess is that, on the surface, free-flows usually get started when the reg is dropped into the water diaphragm-down -- the smack against the surface pops the valve open, and it just goes from there. Yes?

--Marek

Yes, I believe that would be correct. I'm not an expert, but it sounds plausible.