why do regs freeflow on surface?

[fisherdvm]

Why do they, and how do you prevent it? Aside from sticking it in your mouth..

 

[cerich]

finger at the mouth outlet normally will stop it.

not all do, just those that have been designed to deliver positive flow to make it seem like they breath better. Better design stops this problem.

 

[Penguinboy]

I believe freeflows are just when something sticks open inside the reg - for whatever reason. It may well be if they have not been serviced, or of course just serviced badly.

I was taught to almost karate chop it - give it a knock to loosen the parts up again and hopefully stop it sticking.

 

[redacted]

Because a properly tuned 2nd has a cracking pressure (gas starts flowing) of just a little over 1 inch of water. That is, when the pressure difference between the outside of the diaphram and the inside is the same as the pressure of 1 inch of water, the LP seat/poppet is pulled away from the orifice. So if the mouthpiece is pointed upwards at the surface and the regulator is submerged, it should freeflow. That's why I prefer a user adjustable alternate so I can temprorarily set the cracking pressure to over 2 inches so the reg will fill with water before the gas starts flowing and avoid the problem entirely.

 

[do it easy]

Hey fishersdvm, did you forget something? *cough* *cough* poll *cough*

I don't have adjustable regs, so I just point the the mouthpiece downward when I enter the water to relieve the pressure that is causing them to purge (see awap's post). Once under, I'll flood them and there are no more problems.

 

[jonesbf]

I would never hit my reg to make it stop free flowing. Just turn it mouth piece down in the water and it will stop.

 

[scarefaceDM]

What happens is at times, the second stage is dried and is stuck open slightly causing the free flow. As mentioned just stick your finger in it or dunk it in water and invert it (mouth piece facing down ) Or at imes some crudd gets in the diaphram/valve / Purge button and begins to free flow. Again purge the reg dunk in water and invert it. If yours is adjustable then tune it down alittle. Or if it is really PISSING...you may have to open it up to get the the adjusting screw to turn it down some.

If all fails...your screwed!!!! Not really, but you may have to clean the second stage on sight..or get your regs seviced and ask the LDS to show you how to FIX the free flows for next time.

Whacking your second stage is kind of extreme but hey it is your gear...hack away. The simple dunk and breath - works well...or shake the sucker in the water...

 

[Doc]

Whacking your second stage is kind of extreme but hey it is your gear...hack away. The simple dunk and breath - works well...or shake the sucker in the water...

Or while shaking, hit the purge as well.

Whack away. you can do no further damage with your hands. They're tougher than that.

 

[nymbus]

Because a properly tuned 2nd has a cracking pressure (gas starts flowing) of just a little over 1 inch of water. That is, when the pressure difference between the outside of the diaphram and the inside is the same as the pressure of 1 inch of water, the LP seat/poppet is pulled away from the orifice. So if the mouthpiece is pointed upwards at the surface and the regulator is submerged, it should freeflow. That's why I prefer a user adjustable alternate so I can temprorarily set the cracking pressure to over 2 inches so the reg will fill with water before the gas starts flowing and avoid the problem entirely.

Exactly right. If the reg is free flowing on the surface, no where near water, you should have it serviced. However, if it is mouthpiece up and set in the water, the partial pressure will drop, the diaphram will be pushed and it will free flow. Simply turn it mouthpiece down, or if it continues, have your buddy turn your air off and then turn it on again. I too, have been known to gently beat a reg mouthpiece until it stopped, but you really shouldn't need to do this.
Also- this can happen underwater if your reg is out of your mouth too. I suggest making sure that each time you take your reg out, you do two things:
1- if it is adjustable, turn the adjust to the setting that is hardest to breath against
2-make sure that when you remove the reg, you turn it mouthpiece down

 

[JC Franklin]

You guys rock! I had the same question, but was to chicken to ask.