Question Aqua lung core regulator hissing

[Endler's]

Would require a little more inhalation effort, to crack open valve and let gas into stage.

'Majority of safe second octos are purposely tuned this way.

(In effect, not actual practice. The bulk being tuned on benches with test equipment, not in the field like yours was.)

 

[Nemrod]

Thanks that worked perfectly! I might have gone a 1/16 total. What happens if I went farther just out of curiosity?

You only need to turn the orifice in until the leakage stops and then as I said 1/32 to 1/16 additional. Further than that and the cracking effort will increase and the lever height will be lower than spec.

Edit to add: One of the indicators of a worn seat or out of spec/damaged orifice is that the orifice will need to be turned inward more and more until cracking effort will increase beyond specification to get a seal.

 

[happy-diver]

Thanks that worked perfectly! I might have gone a 1/16 total. What happens if I went farther just out of curiosity?

Magnificent job, not scary at all, let's hope you continue to hold reg techs in the high esteem they crave

like some with chocolate

 

[Scoooter961]

You only need to turn the orifice in until the leakage stops and then as I said 1/32 to 1/16 additional. Further than that and the cracking effort will increase and the lever height will be lower than spec.

Edit to add: One of the indicators of a worn seat or out of spec/damaged orifice is that the orifice will need to be turned inward more and more until cracking effort will increase beyond specification to get a seal.

It will be overhauled in January (it was overhauled last January too) but I will mention that I had to adjust it. Also, they supposedly replaced the air spool on my wifes transmitter and it started leaking last trip too. The shop I use in Maryland lost their tech so they send them out, which I don't like at all.

 

[Scoooter961]

You only need to turn the orifice in until the leakage stops and then as I said 1/32 to 1/16 additional. Further than that and the cracking effort will increase and the lever height will be lower than spec.

Edit to add: One of the indicators of a worn seat or out of spec/damaged orifice is that the orifice will need to be turned inward more and more until cracking effort will increase beyond specification to get a seal.

Posted twice (deleted)

 

[mundo121]

If it was doing it since the service, they didn't take the time and service the regulator right. Or they didn't replace all the parts on the service. Would question their work, next time after service ask them to put all the parts they replaced in a ziplock bag to see that everything was done correctly (what parts they used with service kit). That is why a lot of members on here have learned to service their stuff themselves so you know its done correctly and not by shady DS employees.

 

[Scoooter961]

If it was doing it since the service, they didn't take the time and service the regulator right. Or they didn't replace all the parts on the service. Would question their work, next time after service ask them to put all the parts they replaced in a ziplock bag to see that everything was done correctly (what parts they used with service kit). That is why a lot of members on here have learned to service their stuff themselves so you know its done correctly and not by shady DS employees.

It started doing it after about 80 dives. Not since day one but I will ask for the parts back, if they don't have to turn them in for the warranty.

 

[rsingler]

Make adjustments of 1/32 to 1/16 turn per adjustment until leakage stops and then another 1/32 to 1/16 turn.

Thanks that worked perfectly! I might have gone a 1/16 total. What happens if I went farther just out of curiosity?

Would require a little more inhalation effort, to crack open valve and let gas into stage.

'Majority of safe second octos are purposely tuned this way.

NO!
This is how DIY can kill you. @Endler's comment above is true, but apples and oranges.

Turning the second stage orifice in further will drop the lever. It is poorly appreciated how small an adjustment should be made. At depth, (high gas density), a low lever will provide inadequate gas flow and may kill you.

While safe second octos are indeed tuned this way, they are almost all downstream (unbalanced) seconds, where you can raise the lever with the nut, after screwing in the orifice.
The Core is a balanced second.

While a hiss from a worn seat can indeed be fixed with a TINY orifice adjustment, anything beyond 1/6 turn after the reg seals will visibly drop the lever. And a scratched knife edge cannot be adjusted with a proper lever height. It takes too much pressure on the seat to seal.

To the lurkers reading this thread. Please don't tune your leaking gear from an Internet post.
And if you think having the Service Manual will eliminate the "no formal training" problem, read this tuning instruction from the Dive Rite XT2 manual.
"Using the second stage adjusting tool set the resistance to .8-1.0 inches of water."
That's all it says. "Just keep turning the orifice in until you get 1 inch." WRONG!
If you haven't been trained, get someone who has, to help you.

Kudos to @Scoooter961 for not thinking, "if a little is good, more must be better", and for asking questions!

 

[Nemrod]

I am going to stay with exactly what I said. The seat has likely taken a set which essentially results in a high lever, mine (a Core) will sit above the case rim in such case. Turning the orifice in 1/16 to 1/32 turn incrementally until the seat mates with the orifice will drop the lever height slightly (as the seat now engages with the orifice). The lever should be even with the top of the case rim pressurized properly set. If the cracking effort exceeds specification or the lever sits low then it is time for a new seat/orifice or both. Nobody said 1/6 of a turn. That would be far too much and drop the lever below the case rim. You can use a straight edge to verify lever height as acceptable.

So, to restate, for the Ops condition, and only the OP as he described, the seat has likely taken a set in use and the regulator is "hissing" because the second stage was not adjusted to allow for break-in nor possibly cycled sufficiently on the bench. The orifice (crown) can be turned in until leakage stops and then a maximum of 1/32 to 1/16 additional. The lever can be verified as not being low with a straight edge and a cracking effort check made. I will correct one thing, I said 1.8 inches of water as maximum cracking effort, for the Supreme it is actually 1.7 inches, standard model 1.4 inches of water. I would prefer a Magnahelic but a rudimentary test can be done in a sink.

And I have been accused of being a drama queen, geeez. Let me just put this disclaimer in here right now. Anybody who does anything I say or recommend from cameras to fins to plates to regulators, anything I have said in the past, now or ever in the future, will most likely die if they do. So take from that your death is likely from following any advice given by me at any time and go ahead and get that will and testament made out for your survivors if you do. Is that enough drama? Is that clear enough?

 

[Zef]

I am going to stay with exactly what I said. The seat has likely taken a set which essentially results in a high lever, mine (a Core) will sit above the case rim in such case. Turning the orifice in 1/16 to 1/32 turn incrementally until the seat mates with the orifice will drop the lever height slightly (as the seat now engages with the orifice). The lever should be even with the top of the case rim pressurized properly set. If the cracking effort exceeds specification or the lever sits low then it is time for a new seat/orifice or both. Nobody said 1/6 of a turn. That would be far too much and drop the lever below the case rim. You can use a straight edge to verify lever height as acceptable.

So, to restate, for the Ops condition, and only the OP as he described, the seat has likely taken a set in use and the regulator is "hissing" because the second stage was not adjusted to allow for break-in nor possibly cycled sufficiently on the bench. The orifice (crown) can be turned in until leakage stops and then a maximum of 1/32 to 1/16 additional. The lever can be verified as not being low with a straight edge and a cracking effort check made. I will correct one thing, I said 1.8 inches of water as maximum cracking effort, for the Supreme it is actually 1.7 inches, standard model 1.4 inches of water. I would prefer a Magnahelic but a rudimentary test can be done in a sink.

And I have been accused of being a drama queen, geeez. Let me just put this disclaimer in here rightZ now. Anybody who does anything I say or recommend from cameras to fins to plates to regulators, anything I have said in the past, now or ever in the future, will most likely die if they do. So take from that your death is likely from following any advice given by me at any time and go ahead and get that will and testament made out for your survivors if you do. Is that enough drama? Is that clear enough?

So the OP has now dialed in his oriface to stop his 2nd stage from leaking, but is still unsure why it was leaking in the first place.

You mentioned in an earlier post, in response to the OP, that he should check that the IP was within spec. This was a good recommendation but given the OP's initial concern/question and their follow-on questions, it seems you took for granted the OP's level of knowledge about IP, with what and how it is measured, and how it is adjusted. You also added other recomendations that led the OP to take the easy path to just adjusting the orifice.

While the symptom has been taken care of, the problem has not been properly diagnosed. If the IP is causing the issue, changing the cracking pressure by dialing the 2nd stage orifice is a temporary fix at best, but leaving the problem undiagnosed could result in issues when diving the reg at depth. I can't help but think that you have created a false sense of security for the OP, who should have taken his reg to a competent service tech, or done a lot more research before adjusting and certainly before diving it.

-Z