Regulator tuning

[cerich]

if you have a shop set it to the closest to the edge , after a few dives it will freeflow a little bit and will need re-tuned. If you don't know how to do it and need a shop, just have your regs serviced and tuned by a decent tech. Truthfully, the small difference in WOB is insignificant and you are unlikely to notice anyhow. If you can notice, it would be because you are diving and tuning regs a ton, in which case you would know how to do it.

 

[txgoose]

I am surprised by the number of folks in this thread that are unaware of the medical fact that if you set a reg close to the edge, it actually increases the diver's tidal volume. This was covered in one of the Marvel movies. I forget which one though. I really don't feel like you guys and gals are paying attention.

PS, OP, get a new shop!

 

[Daniel M. Thomas]

Thank you all for your replies. It was definitely the same guy (dive shop owner) that i spoke too, i just found it odd that he told me two conflicting ideas. He is walking around in a huge face mask in his shop, behind a plastic screen and seemed overly anxious/worried about coronavirus, i can't blame him for that- so maybe that just has him distracted. I told him i was considering Poseidon regulators after reading on here that they are well designed, and he seems to think that if i bought Poseidon regulators (i was considering trying them before i opted to service my XTX200's) they breathe too easily, the same as if my apeks were tuned to the edge and i would end up using more air.

I will just let him do it as he wishes to do it. I'm sure it will be fine, i was just curious to see how it would feel if it was 'tuned to the edge'.

Can anybody recommend where i would go to find more information and learn how to tune the regulator myself? It's something i would like to learn how to do

 

[James79]

Can anybody recommend where i would go to find more information and learn how to tune the regulator myself? It's something i would like to learn how to do

I learned a lot from VintageDoubleHose.com . at the bottom of his site he has a link to a metric buttload of manuals and other documentation. He also posted a lot of youtube videos on working on the vintage stuff... But reg tech hasn't really changed in 60 years or so. Find the manual for your reg, and the video for the vintage reg that is it's technological fore father, and you're off to the races!
Respectfully
James

 

[JohnN]

Hold on here. . . the XTX200 has an adjustable cracking pressure adjustment knob. If you haven't figured out how to use it, you should. In any case, change your LDS and ignore all the previous BS about "Life support systems" and making adjustments yourself. If your reg did start to free-flow, you would only need to dial the cracking pressure back a bit.

Check out this YouTube on adjusting your secondary:
And here is a picture of the XTX200:

EDIT:

Please pay attention to the bit in the video about depressing the purge valve when making these adjustments. Otherwise, you'll put excessive wear on the valve seat and have to service the regulator sooner that otherwise

 

[cerich]

here is a video I made regarding second stage tuning.. the same will apply to your reg

 

[tbone1004]

If I were being paid to tune a regulator for a customer, then they are set to manufacturers specifications, that is a liability issue. Tuning them "hotter" than that is quite easy to DIY, however there is most definitely a limit that is defined by case geometry where you can tune them hotter on land, but they will freeflow underwater. I doubt that will be much if any lower than 1" H2O on that second stage, but 1" is pretty darned effortless in the water.
What the shop said about using more gas and swallowing some is BS though.

 

[Rusty Shackleford]

If the manufacturer allows a 1.0, that should be good enough.

I have found when I try to tune a conventional reg to less than one, it will free flow slightly in odd positions.

 

[BoltSnap]

The dive shop owner is doing and saying what he should be doing and saying, tune the equipment per manufacturer's specs, or within the range specified by the mfg., nothing more and nothing less. I have played around with my regs. where I tuned them to the edge of free flowing and they would appear to be stable on the surface but they will eventually leak air during the dive at different degrees and waste air and, indeed, increase my apparent air consumption rate underwater (I know what my typical SAC/RMV values are and compare them with values for when I am using a regulator tuned to the edge beyond mfg's specs and I know that it was "bubbling" or leaking air during the dive). In short, stick with the manufacturer's specs, go by the book, live by the book, the book is GOOD!

In regards to the point mentioned by the OP concerning the dive shop owner telling him that he would swallow air and increase his air consumption, I just find it amusing that some folks here took the OP's word at face value and started to tell him to find another dive shop and all of the words that went with that. I don't believe what the OP said concerning this point and I am more inclined to believe that the dive shop owner told him that he would be wasting air thru regulator leaking air and thus influencing his air consumption rate to increase which is very true and is probable should the regulator be tuned to the edge beyond mfg's specs. The dive shop owner was telling the truth, that is all what he told the OP.

 

[axxel57]

If the manufacturer allows a 1.0, that should be good enough.

I have found when I try to tune a conventional reg to less than one, it will free flow slightly in odd positions.

My manufacturer writes that I should adjust my D400/350 to 1,4-1,6 inch/h2o.
Well, that's definitely not good enough for me with that 2nd.
I wouldn't dive my Ds with a cracking effort higher than 0,7 inch/h2o and I haven't realized any free flow in any dive position.....