Apeks ATX50 adjustment procedure

[ranger]

Does anyone have the correct adjustment procedure for the ATX50, after overhaul? I have the ATX Technical Maintenance Manual, which specifies how to install the spring adjuster in the adjuster screw and where to initially adjust it to. The problem I see is it has to be adjusted during the final testing phase of the overhaul to fine tune the reg. The manual does not go into any detail on adjustment, and since I am a stickler for detail, and getting it right, I would like to have this info. Anyone out there willing to give up this information? I know this is right up RescueDiver's alley, how about it?

 

[rescuediver009]

You rang?
Well...... it is the same as any other downstream reg... how about that does that help? I am guessing that you have not done this before? It is done the same way that you initially adjusted it. You just have to keep pressurizing it, test breathe and then readjust to your liking. Lefty loosy, righty tighty... comprende?

 

[ranger]

Been there, done that! I have questions based upon how I understand the reg should operate if correctly adjusted.

If correctly adjusted....with the adjuster fully CCW, venturi switch in +, when purging should get a strong freeflow. Freeflow should be capable of being stopped by rotating the adjuster approx 1 to 2 turns CW, or by putting your thumb over the mouthpiece. Also, with the adjuster fully CCW, venturi switch in the -, when purging should not get a freeflow. Am I correct???????????????

The manual doesn't go into any detail about adjusting the spring adjuster, but I've found by trial and error that it effects the sensitivity of the adjuster. Both of my ATX50's are UK models, and I understand they are very conservative about the adjustments vs the way the US models are adjusted. Out of the box, neither would free flow with the adjuster fully CCW, because the spring adjuster in the adjuster knob was screwed in to its max depth. Any elaboration on the spring adjuster setting from you would be most appreciated.

I'm certified on Dacor, Cressi, USD, Seaquest and Posiedon, but I left the dive shop before the Seaquest line changed to Apeks. This is the first poppet valve I've overhauled, and since its mine I can play with it, but I certainly want it right. From what I'm seeing with the spring adjuster in the adjuster knob, its possible to overadjust it, and practically negate the advantages of an adjustable second stage.
Do you agree??

 

[rescuediver009]

If correctly adjusted....with the adjuster fully CCW, venturi switch in +, when purging should get a strong freeflow. Freeflow should be capable of being stopped by rotating the adjuster approx 1 to 2 turns CW, or by putting your thumb over the mouthpiece.

You can also turn the venturi switch to the minus (-) to stop this.

Also, with the adjuster fully CCW, venturi switch in the -, when purging should not get a freeflow. Am I correct???????????????

You are correct.

The manual doesn't go into any detail about adjusting the spring adjuster, but I've found by trial and error that it effects the sensitivity of the adjuster. Both of my ATX50's are UK models, and I understand they are very conservative about the adjustments vs the way the US models are adjusted.

The spring adjuster can be used to describe the root of this 'problem'. It actually lies with the counter balance cylinder (#4 in the attached diagram). The one shown is the UK model. Take a look at the counter balance cylinder in the first diagram. Notice the little nib on the right side (its the red thing in the picture). Now if you look at the US model (get ready for this, don't say I didn't do anything for you) in the second picture that I editted. You will notice the the nib is missing. This will result in a very slight decrease in breathing. It has something to do with the energy of the spring is not concentrated onto such a small spot. So there you have it. As you mentioned there is another adjustment. Now this is the interesting part. IT is not present on all Apeks second stages. I have noticved a couple different designs in this respect. I do not kow when they changed it but I do know that ideally you want to adjust it so that it doesn't stick out like the end of the counter balance cylinder. You want it flush with the flat end of the metal adjustment knob. Now we are really getting into it. If you adjust it like this and then tune the adjustable orofice, you should do it so that it only trickles. If so you can turn it half a turn to a full turn to stop it. Of course people of your abilities, can adjust the regulator to their own preference, which will ultimately make little difference but also keep you happy. Hope this helps, if not I don't know what I missed.

I'm certified on Dacor, Cressi, USD, Seaquest and Posiedon, but I left the dive shop before the Seaquest line changed to Apeks. This is the first poppet valve I've overhauled, and since its mine I can play with it, but I certainly want it right. From what I'm seeing with the spring adjuster in the adjuster knob, its possible to overadjust it, and practically negate the advantages of an adjustable second stage.
Do you agree??[/QUOTE]

 

[ranger]

Thanks man, you confirmed my suspicions on the adjustments. Now I know I have the reg adjusted correctly, and that I need to touch up my newest of the two. Thanks again!!!!!

 

[rescuediver009]

I put too much effort into that... Let's keep it our little secret :winky: