Adjusting reg by submerging how precise ?

[idive2]

I have been tinkering with a few old regs and have done some comparisons on my newer
reg when submerging compared to some octos. I have estimated the location of the diaphragm
and put some tape on the reg marked every 1/4 inch. I can actually get the flow to start from the
mouthpiece at a lesser measurement by gently touching the purge button. If I don't touch the purge
it starts a little higher on the tape. It will also keep flowing as I raise the regulator to a height below
where it started flowing without touching the purge. I'm not trying to get these regs down as low as
possible just trying to determine within plus or minus 1/4 inch of their actual setting.

 

[KD8NPB]

Why don't you make an "inches of h2o" manometer out of tygon tubing? It'd be quite a bit more precise and less fiddly.

 

[spectrum]

It's all I bother to do and it has worked just fine. If you are careful and know what you are looking for it's first hand information. The downside is that it's a little more interpretive than using a manometer. If you are trying to get within 1/4 you'll know that. At the end of the day if it breathes nice and is not prone to free flow what more do you care?

I have had cause to use the method literally out in the water before descending when a buddy had doubts about how a regulator was performing. You can do it in the lake, you can do it in the ocean, the bathtub, the sink, rinse barrel or the porta-pottie. Well, maybe not that last one.

If you are working with a double hose regulator or trying to compare parts and other variables then by all means use an instrument.

Pete

 

[herman]

I agree, simple and cheap to make and as accurate as it gets.

 

[Nemrod]

Magnahelics are fairly cheap. I have four of them and use them in various set ups to adjust both single and double hose regulators. It is much easier to adjust a regulator and reproduce results consistently using the Magnahelic. As well, an IP gauge can easily be made from a small pressure gauge often available in the tool department such as Home Depot and an old inflator or regulator LP hose.

N

 

[idive2]

Yeah, I think I may pick up one just to do an occasional check. Already set up an IP gauge using an inflator
fitting attached to a 0-160 psi gauge. Just connect inflator hose to gauge for a quick and easy IP check.
I've learned that just a small adjustment can make a big difference in the breathing effort. Don't want anything
free-flowing but I would like it to breathe as well as it should.

 

[Couv]

The sink or bucket method is fine for checking your equipment periodically. Just take note how deep you are immersing the second stage before it begins to freeflow. Compare the cracking pressure from time to time to keep an eye on its performance.

If you're going to service your gear then you'll find it more convenient to have a manometer or magnehelic gauge at your bench.

 

[elan]

If I try to tune my barrel seconds to the easiest breathing using the bucket method the following works for me.

- breath the reg a couple of times to make sure the exhaust valve is not stuck.
- Unwind the cranking effort knob all the way out.
- Plug the mouthpiece air tight, - I usually just use my thumb.
- Submerge the reg diaphragm down - mouthpiece up.
- Tune the micro-adjuster or the orifice to the point that it starts bubbling very slow through the exhaust and make sure it stops then the cranking knob is tightened down about 25%

That would give the setting that is roughly at the sensitivity level that is allowed by the case design.
You will not get a number doing it like that but in most cases I do not care about the number I just want the stage to be tuned at the best level.

 

[idive2]

If I try to tune my barrel seconds to the easiest breathing using the bucket method the following works for me.

- breath the reg a couple of times to make sure the exhaust valve is not stuck.
- Unwind the cranking effort knob all the way out.
- Plug the mouthpiece air tight, - I usually just use my thumb.
- Submerge the reg diaphragm down - mouthpiece up.
- Tune the micro-adjuster or the orifice to the point that it starts bubbling very slow through the exhaust and make sure it stops then the cranking knob is tightened down about 25%

I have a SP G250V and could try this method as well. I did find some pretty reasonable prices on a Dwyer
0-3 inch magnehelic gauge and may pick one up just to do a final check.

 

[Jim Lapenta]

Both of my magnahelics were under $15. I have one set up for inches of water and the other is in millibars.