Free flowing air source at depth

[frozenwarp]

Hi im just wondering what the chances are of my Air Source free flowing at depth as its matched to a legend supreme lx acd (over-balanced)

i've heard this can be a problem

I'm doing my deep/wreck soon and as part of it i will be diving down to 40m (130ft) and obviously dont want a free flow at depth

Any help or opinions would be greatly appreciated

Cheers, Brad

 

[Scottri]

I have an Overbalanced Apeks with a cheap octo and I have taken it below 150' without a free flow.

 

[Web Monkey]

I have no idea about your specific reg, but failures are possible at any depth with any equipment.

Part of your deep/wreck class should cover gas planning (to make sure you and your buddy always have enough gas to safely get to the surface after a failure), emergency procedures (sharing air with your buddy) and redundant equipment (doubles or pony).

Although theoretically possible, an Emergency Out of Air Ascent from 130' would not be my first choice.

S*** happens, and you need to be prepared for it.

Terry

Hi im just wondering what the chances are of my Air Source free flowing at depth as its matched to a legend supreme lx acd (over-balanced)

i've heard this can be a problem

I'm doing my deep/wreck soon and as part of it i will be diving down to 40m (130ft) and obviously dont want a free flow at depth

Any help or opinions would be greatly appreciated

Cheers, Brad

 

[Doc Intrepid]

Brad,

If the reg is properly adjusted it ought to not give you a free flow at depth.

(Even if the reg DOES begin free-flowing at depth, and you can't get it to stop, you know that the proper response is to simply breath normally through the free-flow and slowly ascend, correct? You've generally got plenty of gas to get you to the surface, and if you don't you can always grab your buddy's secondary second stage.)

(Are you referring to an Air Source as a generic name for a second stage, or are you referring to some specific kit similar to a SP Air II?)

Either way, free flows are rare. Popping the mouthpiece will often stop them. If it doesn't, no worries. Breath off the free flowing reg and thumb the dive.

Have fun with your class,

Doc

 

[halocline]

I suspect what you're referring to as a free flow is a slow leak from the mouthpiece, not a full out purge type free flow, correct? The idea is that "overbalanced" 1st stages increase IP above the "X + ambient" value so that as you dive deeper, your IP is actually increasing more than the increase in ambient pressure. Theoretically, if this increase is enough, it can cause non-balanced 2nd stages to free flow, because the cracking pressure on those is set by a spring alone working against IP, where a balanced 2nd stage will have a chamber that essentially negates differences in IP to a point. If this is the scenario, you will either have to increase the spring pressure on your airsource, making it breathe a little harder at less depth, or switch to a balanced 2nd stage for your alternate air source.

 

[Blind]

Can you just switch to your octy then bend your reg hose to stop the flow? I was wondering about this the other day.

 

[Kevin Carlisle]

Hi im just wondering what the chances are of my Air Source free flowing at depth as its matched to a legend supreme lx acd (over-balanced)

i've heard this can be a problem

I'm doing my deep/wreck soon and as part of it i will be diving down to 40m (130ft) and obviously dont want a free flow at depth

Any help or opinions would be greatly appreciated

Cheers, Brad

I have the same reg and an airsource 2 and have never had a problem. Been down to 140 several times.

 

[frozenwarp]

Cheers for the replies guys i think it all should be fine im not particually worried i just thought i'd see what everyone thought.

Brad,
(Are you referring to an Air Source as a generic name for a second stage, or are you referring to some specific kit similar to a SP Air II?)
Doc

It is an aqualung air source (same as an AirII)

Cheers all,

Brad