Intermediate Pressure, Apeks v. Auqualung

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

ChrisA

Contributor
Messages
1,301
Reaction score
2
Location
Redondo Beach, California
# of dives
200 - 499
I have an Apeks ATX50 but it has one of theose low profile Aqualung octs on it. I've been having problems with the octo free flowing. I can make it stop it that required pilling the cover and diaphram off and a bucket of clean water, simply working the purge valve while in the ocean does not work. It still makes bubbles. Regs got service twice last year 60 then 125 dives. It's been only a half dozen dives since last service.

Ok now here is the question. Are the Apeks and Aqualung designed to use the same intermeddiate pressure. I'm thinking that the IP may be to high for thr Aqualung Octo..

I actualy had to use the octo today. A wave ripped the primary reg off the moulthpiece.
I sucked in some water, blow out to clear which of course didn't work so I went for the purge then found no reg. So I use the octo but it's got a mild free flow ging

OK new oct time. I've got a nice new Aqualung "partner" reg with a nice new full size 2nd stage that I could use. But if the IP pressure is the problem this is not a good fix. I'll have to go buy and AT20 2nd.
 
This a part of a reply I wrote in a more tech type forum. The problem should sound familar. Your octo is unbalanced BTY. Bottom line where you bought it does not understand what they are selling. You need a balanced octo. It is all a function of the overbalanced first stage.

"To be honest the most common Apeks complaint I see is the octo free flowing at depth. This is because shops don't understand that the unbalanced Apeks(they call them "over balanced"- yes I am poking fun here) should not be paired with an unbalanced octo. As the IP increases beyond the ambient pressure increase the IP will overcome the set cracking pressure, usually set below 2" and the octo will freeflow, come shallow and it goes away and when the poor ******* tells the shop that sold it to them they throw it on a tank and hear no freeflow and tell the poor slob cust that it's OK now....until the next deep dive. They may tune it so it won't, then you have a unacceptable cracking effort and no purge left. So with those first stages you need to go the balanced octo route, more expensive and more likely to go from bad to worse if you have a complete HP seat failure. Ever wonder why Scabbiepro has never made a balanced octo? They would make more money selling them... guess it is only computers they are willing to sell knowing they ain't safe.. :)
 
Had the same problem, same setup. Bought a Titan octo, problem solved. It freeflows like a demon at the surface til it gets good and wet, then works great.
I had to breathe off of one of those LPOs this morning in a class drill...thought I was gonna die after breathing the Apeks first.
 
It shouldn't freeflow at the surface....
 
Not really a freeflow, just an upside down position hanging from the octo holder bubbling thing for a few seconds.
 
The problem does not occure at depth, well not at the depths I dive which is about 110ft or above. The problem happens in a test bucket at home at 1 ATM.
It mostly happens while beach diving. I think it is realated to fine suspended sand BUt other
divers with other equipment don't have this problem

cerich:
.....
"To be honest the most common Apeks complaint I see is the octo free flowing at depth. This is because shops don't understand that the unbalanced Apeks(they call them "over balanced"- yes I am poking fun here) should not be paired with an unbalanced octo.....)
 
what is the IP of the reg?
 
ChrisA:
The problem does not occure at depth, well not at the depths I dive which is about 110ft or above. The problem happens in a test bucket at home at 1 ATM.
It mostly happens while beach diving. I think it is realated to fine suspended sand BUt other
divers with other equipment don't have this problem

first is the bubbling consisten or does it pause?

take a breath off your primary and watch the octo, does it momentarily stop bubbling??

Many freeflows I have seen is from a creeping ip... the ip becomes stable when one of the regs bleed the excess pressure or if the reg is breathed from..

You need to put a guage and monitor the IP..
 
ChrisA,

The IP used on an LPO and ATX are within +/- range and from what you say (re # dives since service & type of freeflow) on an ATX we would not expect to see any creeping of the IP, the seat used by Apeks is the best out there. (I also assume the LDS didn't set IP over spec)

Now its true you should use a balanced 2nd stage with the Apeks "over balanced" 1st stage but in practice the IP increse over ambient is not that great and within rec limits would not normaly (in my expirence) cause a free flow.
Note: "Over balanced" is not new, Dacor of old used it 10-15 years ago (thay called it "Turbo Boost") and sold it with non balanced octos no probs (well apart from the usual Dacor probs).

Now the LPO on the other hand, not even Aqualung could get them all to work right first time! We had to adjust loads of these octos from new as we sold them. For you to have your free flow is sadly almost "normal"! The LP seat used will "bed in" after a service and due to the small size you don't have much lever slack to play with. Your octo just needs a tiny tweek, go see LDS.

Now if you have a Caylpso/Titan 2nd stage from a Partner this is also an "un-balanced" 2nd stage (Titan LX/Legend octo is balanced) and also not ment for the ATX, but, real world, it breaths 10 times better then an LPO and is a much better choice.

So for you, a trip to your LDS, get the LPO adjusted, make sure the IP is within specs and not creeping (like thats go'na happen), have the other octo fitted and keep LPO as a spare!

Or if your a Divemaster then just beat it on the boat rail till it stops!!!


Any way thats my opinion, and i'm sure some one will disagree, after all what do I know about regs?
 
https://www.shearwater.com/products/perdix-ai/

Back
Top Bottom