Scubatools.com , trying to understand purpose/logic of a couple 2nd stage tools ?

[LeadTurn_SD]

Here are the basics.

Rightie-tightie, Leftie-loosey.

Clockwise = harder breathing. Counter-clockwise = easier breathing.

Turning the orifice clockwise, whether using the fancy inline adjuster, or a screwdriver or allen wrench results in increased seating pressure against the soft seat, AND lowers the demand lever.

Turning the orifice counter-clockwise reduces pressure against the soft seat AND raises the demand lever.

Remember, moving the orifice changes both the amound of pressure being placed against the soft seat and the lever height.

If it hisses at you, turn it clockwise.

If it is silent, turn it counter-clockwise until it hisses, then clockwise until it just stops.

And to think, they said tuning a regulator should only be left to trained professionals

Others will chime in with more detailed (and better!) procedures, but in a nutshell that is really about all there is to it.

Oh yeah, and remember you've already been admonished to ALWAYS hold down the purge while moving the orifice.

Perform all adjustments with the knob on the 2nd stage set to the easiest position (full counter-clockwise).

A very slight hiss (VERY slight) is acceptable at the easiest position, with understanding that just a slight turn of the adjuster will stop the leak, but I typically tune all of my adjustable 2nds to the easiest setting that does not leak... this allows me a little leeway in case I did not adequately break in the seat prior to diving it.... generally the soft seat will take a set after a couple dives, and if you tune right to the very edge you may find you need to break out the inline adjusting tool and retune it... which is acceptable too. After you tune a few, you'll get the feel for how "hot" you can go on tuning.

Best wishes.

 

[scubafanatic]

Here are the basics.

Rightie-tightie, Leftie-loosey.

Clockwise = harder breathing. Counter-clockwise = easier breathing.

Turning the orifice clockwise, whether using the fancy inline adjuster, or a screwdriver or allen wrench results in increased seating pressure against the soft seat, AND lowers the demand lever.

Turning the orifice counter-clockwise reduces pressure against the soft seat AND raises the demand lever.

Remember, moving the orifice changes both the amound of pressure being placed against the soft seat and the lever height.

If it hisses at you, turn it clockwise.

If it is silent, turn it counter-clockwise until it hisses, then clockwise until it just stops.

And to think, they said tuning a regulator should only be left to trained professionals

Others will chime in with more detailed (and better!) procedures, but in a nutshell that is really about all there is to it.

Oh yeah, and remember you've already been admonished to ALWAYS hold down the purge while moving the orifice.

Perform all adjustments with the knob on the 2nd stage set to the easiest position (full counter-clockwise).

A very slight hiss (VERY slight) is acceptable at the easiest position, with understanding that just a slight turn of the adjuster will stop the leak, but I typically tune all of my adjustable 2nds to the easiest setting that does not leak... this allows me a little leeway in case I did not adequately break in the seat prior to diving it.... generally the soft seat will take a set after a couple dives, and if you tune right to the very edge you may find you need to break out the inline adjusting tool and retune it... which is acceptable too. After you tune a few, you'll get the feel for how "hot" you can go on tuning.

Best wishes.

On the concept of how 'hot' to tune it, what is the best compromise ? Easy breathing is preferred, but I don't want excessive instability either (meaning free flows when facing down underwater or facing into a current or giant-striding off the deck of a boat).

 

[redacted]

On the concept of how 'hot' to tune it, what is the best compromise ? Easy breathing is preferred, but I don't want excessive instability either (meaning free flows when facing down underwater or facing into a current or giant-striding off the deck of a boat).

For a DIYer, this is quite easy to manage. For user adjustable 2nds, any slight leak that may occur is easily managed with a small adjustment. For any 2nd with an adjustable orifice, it is a 5 minute job to grab the tools from your save-a-dive kit and make a 30 degree turn on the orifice.

There are some 2nds that are not user adjustable and even a small adjustment may be a bit complex (Scubapro D-series and Pilot). But they also tend to be quite stable even when tuned a bit hot. There is really no noticeable performance advantage in going right to the edge anyway. And, finally, even a reg that has a slight hiss due to overly aggressive adjustment will probably be fine for the dive at hand. They just don't lose that much gas. So play around with it and see what you prefer.

 

[LeadTurn_SD]

^^What awap said^^.

scubafanatic: Your 109's are among the sweetest, best mannered 2nd stages out there regarding "tuning". I don't know why, but mine seem to "hold" their tuning better than any other 2nd stages I own.

It is certainly possible to tune a 2nd to breath "too easily"... the result will be a "fussy" 2nd stage. This is only a big problem with 2nd's that do NOT have external resistance adjusters (like my Mares Abyss 2nd's, and I've learned the hard way not too tune them TOO hot!).

It is NOT a safety issue. As awap mentioned, what will typically happen if you get a little too "frisky" with your final tuning is that the 2nd stage will leak slightly during the dive, especially in certain positions. You'll discover the 2nd is bubbling a little in between breathes... you can usually crank down on the adjuster knob just a bit to stop the leak and continue the dive, and then make a mental note to do a quick touch-up tune when you get home, or back on the boat or beach between dives.

The goal is always to aim for the easiest-breathing 2nd that is still stable... if you overshoot that mark, it should not ruin your dive day.

Best wishes.

 

[Nemrod]

I have several inline tools, including the one linked in there OPs post, and I do de-pressurize before turning the tool to prevent damage to the seat. It still saves a lot of time because I do not have to R&R the LP hose between cycles.

I prefer a separate IP gauge on a short LP hose for setting IP. IP is set static, not while under flow to the second stage. I do feel you can get a better idea of IP drop under dynamic conditions with the gauge inline to the second stage.

I prefer this tool for my Conshelfs:

Shop Online

N

 

[scubafanatic]

OK, so I've completed preliminary orifice checking/tweaking on (4) complete regs sets ......(4) MK 5 / 109/156 sets, IP is pretty much spot on @ 135 PSI on all 4 sets, most of the 2nds needed little if any adjustment, so I feel good on the progress so far. I just need to pick my pony bottle next weekend to do final leak tests/fine tune the 2nds, and I need to let the regs sit pressurized overnite to help complete 'break-in'.

 

[Couv]

Cycle each 1st stage 20-30 times or leave them pressurized overnight to break them in. The second stages are already broken in, so once you've adjusted them you're done.

 

[scubafanatic]

Cycle each 1st stage 20-30 times or leave them pressurized overnight to break them in. The second stages are already broken in, so once you've adjusted them you're done.

Thanks as always !