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

[halocline]

I believe that you do most of the initial adjustment without the regulator pressurized, then just fine tune it with the tool. As such, you are not turning the orifice much while it is against the soft seat. Less than a full turn.

It is a valid question, though!

 

[redacted]

With an in line adjuster the regulator should be pressurised otherwise you obviate the whole point of the in line adjuster.

OTOH if you depress the purge on a pressurised reg whilst using an in line adjuster then air will escape from the reg and again you'll obviate the reason you're using an inline adjuster in the first place i.e. to adjust the orifice until no air comes out.

Yes, the orifice can indent the seat if you don't depress the purge but unless you spend a good few minutes grinding the orifice back and forth you'll put no more damage on the seat than the first dive after service will anyway.

The problem may be more than indentation. A sharp orifice, and many are, may cut the seat. Think of it like shaving. As long as you pull the blade straight, you should be OK. But get a little sideways movement in the blade against the skin and the blood flows. Once you cut the seat, it will not work. So, even with the inline tool, you probably should be pressing that purge button a little once the orifice is close to making contact with the seat.

 

[LeadTurn_SD]

OK, I'm seeking clarification, so please confirm my understanding below:

if I use a screwdriver to adjust the orifice, meaning the reg is NOT pressurized while I'm adjusting the orifice, I need to press the lever/diaphragm down while simultaneously turning the screwdriver on the orifice.

If I instead use the inline adjustment tool, and DO have the reg pressurized while adjusting the orifice, then I do NOT need to be pressing down on the lever/diaphragm while simultaneously using the inline adjustment tool.

...is this correct ?

One more voice chiming in wont hurt

Depress the purge button even when using the inline adjuster with the reg pressurized.

Some (many?) may say that depressing the purge is not necessary when using an inline adjuster with the reg pressurized, because air pressure is being exerted against the soft seat, mostly counteracting the spring pressure thus reducing the absolute pressure of the orifice against the seat surface... thus the belief that you cannot cut the seat by moving the orifice.... but I still say nay, don't do it.

You do not negate the advantage of using the inline adjuster. I simply press the purge just enough to cause a "hiss", make my adjustment, release the purge, and go back and forth slightly with the orifice depth a few times until I have the cracking pressure right where I want it, test purge it quite a bit to make "sure" (and to help establish a seating groove), and call it good.

The whole process is quite fast, absolutely eliminates any chance of cutting the soft seat, and helps "break-in" the seat all at once.

It is a "win-win". There is no downside to holding down the purge slightly for the fraction of a second that you are turning the orifice.

There is a downside to cutting a soft seat by not holding down the purge. I have been "ham-fisted" and cut a soft seat, just once, to my great embarrassment :blush:. And this was with a plastic orifice. If you do that, the seat goes in the trash.

As you do this more often, you'll get a feel for what is "ok", and what is not. I have been in a hurry, forgot to depress the purge while adjusting the orifice, and no harm done. But then there was that time I ruined a seat by being clumsy... so cautious is better.

Best wishes.

 

[ams511]

I have been "ham-fisted" and cut a soft seat, just once, to my great embarrassment :blush:.

I have done the same as I am sure others have also.

 

[Couv]

One more voice chiming in wont hurt

Depress the purge button even when using the inline adjuster with the reg pressurized.

Some (many?) may say that depressing the purge is not necessary when using an inline adjuster with the reg pressurized, because air pressure is being exerted against the soft seat, mostly counteracting the spring pressure thus reducing the absolute pressure of the orifice against the seat surface... thus the belief that you cannot cut the seat by moving the orifice.... but I still say nay, don't do it.

You do not negate the advantage of using the inline adjuster. I simply press the purge just enough to cause a "hiss", make my adjustment, release the purge, and go back and forth slightly with the orifice depth a few times until I have the cracking pressure right where I want it, test purge it quite a bit to make "sure" (and to help establish a seating groove), and call it good.

The whole process is quite fast, absolutely eliminates any chance of cutting the soft seat, and helps "break-in" the seat all at once.

It is a "win-win". There is no downside to holding down the purge slightly for the fraction of a second that you are turning the orifice.

There is a downside to cutting a soft seat by not holding down the purge. I have been "ham-fisted" and cut a soft seat, just once, to my great embarrassment :blush:. And this was with a plastic orifice. If you do that, the seat goes in the trash.

As you do this more often, you'll get a feel for what is "ok", and what is not. I have been in a hurry, forgot to depress the purge while adjusting the orifice, and no harm done. But then there was that time I ruined a seat by being clumsy... so cautious is better.

Best wishes.

What he said.

Even though one of my mentors said it is OK to adjust the orifice with the in-line tool while pressurized, I've had mixed results.

 

[raftingtigger]

I use the tool from VDH and connect in a in-line shutoff valve (ILSV) to the tool. My procedure is assemble everything: tank valve outward --> 1st stage --> LP hose --> in-line shutoff valve --> in-line adjustor tool --> 2nd stage. Pressurize the tank, open the ILSV and check for air leakage. Then close the ILSV, press the purge button, adjust the orifice. Repeat until satisfied.

 

[scubafanatic]

I use the tool from VDH and connect in a in-line shutoff valve (ILSV) to the tool. My procedure is assemble everything: tank valve outward --> 1st stage --> LP hose --> in-line shutoff valve --> in-line adjustor tool --> 2nd stage. Pressurize the tank, open the ILSV and check for air leakage. Then close the ILSV, press the purge button, adjust the orifice. Repeat until satisfied.

I'd thought of this procedure myself, except for the clever use of an 'inline shutoff valve' (I was just planning on turning the tank valve on and off repeatedly) I have 'ILSV's in my inventory, so I'm going to adopt your suggestion!

My scubatools order arrives next week, so hopefully by next weekend I can start the 'experiment'.

---------- Post added August 3rd, 2014 at 04:47 PM ----------

It has been suggested to me today (by couv) that it may not have been a good idea to leave my newly serviced 2nd stages with their adjustment knobs fully screwed down (for approx 5 days). The theory behind this was to help break in the seats. All the 2nd stages were unpressurized during this time, sitting 'loose' in the shipping box. Was that a big mistake, now requiring seat replacement ?

 

[Couv]

It is not likely that the seats were damaged due to the knobs being in all the way, however they may have taken a "set." This is no problem and easily dealt with by adjusting the orifice in until the freeflow stops. Again, I will remind you to depress the purge slightly while adjusting.

 

[scubafanatic]

It is not likely that the seats were damaged due to the knobs being in all the way, however they may have taken a "set." This is no problem and easily dealt with by adjusting the orifice in until the freeflow stops. Again, I will remind you to depress the purge slightly while adjusting.

Thanks Robert! Scubatoys parts arrived today, Scubatools order still in transit, plan is still for me to try my hand at the adjustments and we'll see how it goes. Karl

 

[scubafanatic]

I forgot to ask, when adjusting the orifice, which way am I supposed to turn the inline adjuster tool knob ? When to I turn it clockwise and when do I turn it counterclockwise ?

OK, I've got 4 full sets of MK 5's/109-156's assembled. (each set consisting of (1) 1st and (2) 2nds, and an SPG) With trial and error it appears I had to use the inline adjuster tool 'deep reach dimple' feature so the tool had enough "reach" to get to the orifice itself. The 'dimple' feature isn't completely clear in the instruction manual, but I figured it out. I'm just now getting a feel for how to tell when the tool is actually engaged.

I'll only have time to experiment with one set tonight, the IP is in the 125 - 135 psi range for 'unit # 1' as I'll name it, so that should be fine for a baseline on which to adjust the orifices on both '2nd's'.

The inline adjustment tool does appear to be working, so my next question is : what is the optimum free flow adjustment point ? Meaning do I want the 2nd stage adjustment knobs to be dialed all the way out before they begin a hint of free flowing

(BTW, the LP inline shut off valves are proving to be VERY handy too!)

Once I have a chance to fine tune all 4 sets next weekend, I'll then be doing a final leak test on each set via pony bottle/bath tub to eliminate any small leaks, if any.