is there a 'downside' to boosting the IP to increase 2nd stage performance ?

[scubafanatic]

...I'm not concerned about cold-water free-flow issues, the regs in question ( Atomic B1/T2 , Mares Voltrex, Mares Ruby, Poseidon Jetstream ) are strictly warm water, ocean dive regs, with the occasional trip to the local fresh-water springs with steady 70-72 degree waters. I'd like to make sure my regs can cope with deep dives without any noticable performance declines, so I'd like to adjust the IP's to the top of the manufacturer's recommended range, perhaps even a bit beyond it.......will this compromise reliability/safety in any way ?

Thanks,

Karl

 

[FFMDiver]

...I'm not concerned about cold-water free-flow issues, the regs in question ( Atomic B1/T2 , Mares Voltrex, Mares Ruby, Poseidon Jetstream ) are strictly warm water, ocean dive regs, with the occasional trip to the local fresh-water springs with steady 70-72 degree waters. I'd like to make sure my regs can cope with deep dives without any noticable performance declines, so I'd like to adjust the IP's to the top of the manufacturer's recommended range, perhaps even a bit beyond it.......will this compromise reliability/safety in any way ?

Thanks,

Karl

I dont think some of those you mentioned are strictly warm water regs. Some would scold you and tell you to let the LDS handle this. IMHO I wouldnt exceed manufacturer's limit - I suspect extra psi on seat & o-rings in 2nd stage wouldnt like it. Increase it too much and the regulator might unscrew and a spring might fly out (depending on model?).

 

[Al Mialkovsky]

Don't even think about adjusting your IP higher than manufacturers specs. If your reg doesn't perform well enough set that way, then get a better reg.

 

[Rick Murchison]

Well, lessee now... if you increase IP you'll need to make a corresponding adjustment to the cracking resistance to keep from free flowing... and once open the second stage valve would free flow easier with higher IP...
Somehow that doesn't compute with "increase 2nd stage performance."
Rick

 

[scubatoys]

With a reg like the Ruby, which is nothing more than an abyss with a different seat, I'm pretty sure you won't have to monkey with the IP for the depths you plan on going. The Abyss set a record a year ago at 1050 feet... It should handle what you are doing. Same would be true of the Atomics. Remember that the IP of the reg changes with depth. It is 145 over ambient... so as you descend, it is taking the depth into account.

 

[H2Andy]

I'd like to adjust the IP's to the top of the manufacturer's recommended range, perhaps even a bit beyond it.......will this compromise reliability/safety in any way ?

not sure, but it won't help, probably... also, i can hear their lawyers laughing right now:

"dude EXCEEDED the clearly stated manufacturer's reccomendations? does the
warranty still cover it? hahahahhahaah! are we liable for anything that happens?
hahahahahaah!!!!"

or something like that :14:

 

[scubafanatic]

With a reg like the Ruby, which is nothing more than an abyss with a different seat, I'm pretty sure you won't have to monkey with the IP for the depths you plan on going. The Abyss set a record a year ago at 1050 feet... It should handle what you are doing. Same would be true of the Atomics. Remember that the IP of the reg changes with depth. It is 145 over ambient... so as you descend, it is taking the depth into account.

...Thank you, Larry, for your thoughtful response....what prompted my question was a few months ago I was in the market for a cold-water-kit for my Mares (Ruby and Voltrex) , not so much for cold-water protection and for the enviromental sealing aspect, especially when I'm on a live-aboard dive trip for a week and don't have the opportunity to rinse my regs for a week....but a local Mares dealer advised me they'd have to 'drop' the IP from 145 psi to 135 psi to make room to install the kit, and he added it would reduce my performance at depth, so it would be a trade-off, so I elected to abandon the enviro-kit modification at that time.......thus I thought, if a 10 psi IP difference in the downward direction made a material performance reduction, wouldn't an 'upward' IP adjustment of maybe 10 psi in IP setting/adjustment lead to a material performance increase ?

...don't worry, I don't adjust my own regs, I leave that to my local, trusted dive shops....and, no, I'm not planning to ask a dive shop to do something 'stupid' to my reg that puts either them or myself at risk.....I'm exploring the possibility of the pros/cons of making that adjustment, and would appreciate a logical explanation of the consequences......are we talking about slightly accelerated wear on some O-rings/seats/etc., or am I comtemplating turning my reg into an instant death-trap ?

I get annuals on my regs yearly/ after 50 dives, give or take, so I'd happily match my regs against anyone else out there from a care/maintainance perspective, I certainly don't abuse my regs, but since I get frequent inspections/service and don't go years/ 100's of dives between services, I'm not too worried if the worst 'fallout' from boosting the IP a bit is slightly increased wear, since I get my regs serviced well before any problems ever surface anyway.

Karl

 

[John C. Ratliff]

I dont think some of those you mentioned are strictly warm water regs. Some would scold you and tell you to let the LDS handle this. IMHO I wouldnt exceed manufacturer's limit - I suspect extra psi on seat & o-rings in 2nd stage wouldnt like it. Increase it too much and the regulator might unscrew and a spring might fly out (depending on model?).

I don't recommend that any diver who is not familiar with regulators actually work on the regulator, and reset the interstage pressure. You need tools to do this, and you need a familiarity with the specific regulator in question.

That said, there are a few things to know. First, apparently regulator manufacturers routinely set the breaking resistance for an inhalation at about 1.25 inches to 1.5 inches of water pressure. This is because the design of the regulator is such that the exhaust valve, in certain positions, can be about an inch above the center of the diaphragm. If the regulator is set to a lesser breaking resistance, then it can bubble a bit in certain positions, because the water pressure on the diaphragm is greater than the vertical distance at the top of the exhaust valve, and water pressure itself will cause the valve to leak. The extra psi will not harm the seat (it actually takes spring pressure off the seat in a downstream second stage valve). Nor will the O-rings suffer. But it could be inconvenient to have the second stage bubble when you are head down (or with FFMDiver's regulator, turned on his side with the exhaust straight up), especially if you are taking a photo of a fish at the moment with a macro lens setting on the camera.

What you can do is take it to the LDS, and ask that it be set at 0.75 or 0.5 inches of water pressure breaking resistance in the second stage for your primary regulator (don't do this with a safe second or octopus, as it will bubble and free flow when you enter the water). Have them put the regulator on a magnahelix and adjust it for you, then try it out.

Concerning depth, mostmodern regulators (post 1970s) have a venturi effect built into the second stage, and they actually become more efficient and better breathing regulators at depth. This is because the air (or nitrox) is denser, and causes the venturi to work more efficiently. Some also now have depth compensation built into the first stage for purposes of making the regulator breathe better.

SeaRat

 

[rescuediver009]

I am not too sure who fed you the line that in order to install and environmental kit the IP has to be dropped. From a technical side of things it does not make sense. All they are doing is replacing the endcap with one with threads on it, filling it with a load transmitting liquid, and capping it. So whether the water increases your IP as you descend or the env. kit does, makes no difference. I would have stuck with the kit for salt water though. That's a good idea.

 

[Viscya]

Mares calls it a Cold Water kit. It is normal practice to drop the IP of regs used in cold water to reduce the chance of the second stage freezing. Mares instructions probably tell the LDS to do this.

I would listen to Larry on the IP. You are not likely to notice a 10 psi change in IP (which is < 10% of the IP). The reg is designed to operate at a specific IP, and all of the designed is predicated on that range. You are much more likely to notice a poorly tuned second stage. The MR-22 held the world record, and performs well without having to up the IP. My 4 year old Abyss has been to 240 fsw with no noticeable loss of performance.

As far as sealing your first stage for a live aboard trip, your main issue is the sea water drying up and salt crystals forming around the spring and diaphragm. In most climates where liveaboards operate, the humidity is close to 100% and the salt water will not have much time to dry. I just poured a glass of fresh water into the low pressure opening of the first stage and the mouth piece of the second stage after each dive. No one on our trip had any problems with their regs. Soak them good when you leave, or you might want to have them serviced when you get home.