Apeks AT20 leaks at depth

[Jason McK]

I've been finding as of late. My Reg leaking between breaths. As I exhale and about to inhale I hear bubbling. This of course causes me to pause and listen. And sure enough the reg is leaking. I noticed this after about 15 dives on it and had it serviced but it continues to do it. I is fine on the surface of the first dive but once at depth it begins. So I guess you could say it's fine when attached to the tank until underwater. But continued until the pressure of the tank is shut off. I haven't followed up with my Dive shop, thought I'd ask here first.
Once I've finished my dive I can hear it leaking at the surface and if placed in the water it slowly bubbles.
Anyone had any experience with this. Or know what I can tell my Dive shop to help them narrow down the cause

Thanks
Jason

 

[jeckyll]

I think you should describe to the shop what you described here.

 

[halocline]

Try hooking it up to a tank, pressurizing, then turning the tank off and letting it sit for several minutes. See if the tank pressure goes down. You can also submerge the 2nd stage in a sink or something while pressurized and wait for bubbles. Another quick test is to see if the reg holds a tight vacuum while connected to a tank with the air off by trying to draw any air. (use some effort!) If none of these things on land reveal any leakage, then I suppose I would suspect IP creep, (likely) or (much less likely) an effect of the "overbalancing" increase in IP that some apeks regs are supposed to have. Higher IP could cause a slight free-flow in your 2nd stage, although if it is also balanced, it's really not supposed to. If you have an IP guage, you can hook up the reg to a full tank, cycle it a few times, then leave it pressurized for several minutes to see if the IP is slowly creeping upward.

I'm just a brand new DIYer, so take my suggestions with a bit of caution!

 

[DA Aquamaster]

A leaking high pressure seat in the first stage will eventually cause the intermediate pressure to increase to the point that the excess pressure is vented through the second stage as a slight freeflow.

Since the slow leak takes some time (a few seconds to a few minutes) to build up enough excess pressure, a delay in the leak occuring after the reg is pressurized (or after the last inhalation) is usually symptomatic of a high pressure seat leak.

On the other hand, a leaking low pressure seat in the second stage will normally start immediately once the reg is pressurized (or alternatively as soon as the reg is cycled) with no delay. It is not uncommon for these leaks to get a little worse as the dive progresses. It is very common for this to occur on arecently serviced reg once the seat begins to develop a seating groove. The fix is to readjust the orifice and takes abotu 2 minutes.

Another source of leaks in second stages with an adjustable orifice is the o-ring that seals the orifice in the inlet body. Sometimes these are not changed at the annual service. They act just like a low pressure seat leak, except of course they do not go away when the seat is changed.

Cycling the reg a few times then turning it off, noting the high pressure gauge reading, then coming back in a few minutes to se if there was much of a drop is a good way to check for leak somewhere in the system. Doing it in a bathtub is then a good way to isolate exactly what is leaking if the leak is not through the second stage.

I don't think the "overbalanced" explanation is the problem, given that it continues to leak on the surface after the dive and because I also think the overbalanced thing is just marketing BS anyway. Even if it were, the solution would be a regulator adjustment.

 

[keyshunter]

The AT20 is the one Apeks reg that is not touted as being overbalanced. The (possibly mythical) overbalancing is said to be a function of the second (environmental) diaphragm, which the AT20 does not have. Thus it is not designed for cold water. It has, however, a very small, light, first stage, and is really a nice breathing reg. As far as the leak--what DA said.