How important to have same regulator setup for tec

[jgttrey]

I am happy and willing to take advice from more experienced divers - and I do know who Bill Main is. But that doesn't make it gospel (and I would suspect he did not intend it that way either, but of course I was not there). People say a lot of things.

Let me ask this: are there any real life examples of simultaneous identical double-failures attributable to conditions where where simply having a different model or mfg would have made a difference?

I understand the theory perfectly. But it strikes me as just that -- a purely notional consideration that if it offers any advantage, is vanishingly small.

 

[PfcAJ]

who is he to make that doctrine? Also how do you know that is his argument for using different regulators?

Who's to say that the same shop didn't service both scubapro and apeks? Who's to say it wasn't the technicians fault? Who's to say it wasn't a mass bad-batch of HP seats that are shared from different manufacturers *which is a thing btw*. Those failures are arguments for not servicing both posts at the same time with the same batch of parts, but not for using different regulators altogether.

Case and point, the link that @PfcAJ has a lot of incorrect information on it in the discussion of regulators. There is nothing inherently "better" about a balanced second stage, it is less sensitive to fluctuations of IP, but it is not an inherently "better performer". The higher IP does not make more gas "available" to a diver, even at 80psi it will deliver more gas than you can breathe, but it does help counteract the spring pressure "better" on unbalanced second stages which will make them breathe more smoothly.
There is discussion that unbalanced regulators should only be used shallow and for low-demand. They still depth compensate and the lack of balancing is as a function of tank pressure not depth. There is nothing about them that makes them able to respond slower or provide less gas than a balanced equivalent. It certainly applies to a MK2 vs a MK25, but that is on a specific regulator, not a design of regulators.
This is coming from a highly lauded training agency and there is incorrect information on their site. Who's to say that Bill isn't using those regulators because he's been using them for 30 years and doesn't have a need or desire to get new/different regulators?

"Theres nothing inherently better....except these things that make it better....but its not better"

Yeah ok.

 

[tbone1004]

Because I asked him.

Do you know who Bill is?

yes I'm well aware of who he is, and I've met him, though haven't asked him about why his regulators were mismatched. Last I heard he was using Conshelfs because they didn't have a poppet at all and were tilt valve regulators.
WKPP is using MK25's, have the wing on the right post which he is firmly against, etc etc.
The point is not who he is or what he did 30 years ago, it's what drove those decisions in the first place and whether that experimentation has continued.

@PfcAJ their implication is that the balancing makes them inherently better performers. That is an incorrect statement and you can "unbalance" a G250 and make it spit out the same WoB and cracking effort as a normal one if you change to the old 109's duro poppet. What makes them useful is in adapting to imperfect balancing of the first stage, and no first stage *especially pistons* are perfectly balanced so you can get a more consistent WoB regardless of tank pressure.
Doesn't make them inherently "better performers" because the balancing is only necessary to compensate for an imperfect first stage.
Does it make the balanced second stage "more ideal"? Sure, but it's not a "better performer" as they wrote it on the page.

More importantly, I'm curious about the argument on why a 109 is more reliable than a G250 because it's unbalanced, preferably with data on balanced second stages failing because of the balancing mechanism.


Of interesting curiosity in all of this. The Poseidon MK3 first stage has the least amount of moving parts and seals of any first stage on the market. The Jetstream/Xstream second stages are unbalanced, designed around an IP of 123psi, have less moving parts/seals than any other second stage, better WoB, and some of the performance under cold/deep conditions.

 

[fullytek]

All the 4 pages of this set aside
I dive similar regs on left and right post becaus I like things that match and becaus I see value in being able to interchange regs for other aplacations. I like the simplicity of stocking 1 parts kit. And for me it works.

Now there is no single good reason that you must have a matched set of regs for tek diving.

All regulators today including the value priced regs are dam good . If you are have a ds4 and find a good deal on a hog and are ok with having to seek service from different shops,then buy it.

If your tek instructor is adamant that your regs match or must be a specific brand then it's time to get a new instructor not a new reg.

 

[rjack321]

They'll write songs about this!

They already have

I don't worry about matching regulators, but I also don't use unbalanced pistons (like a mk2 + 190 2nd) anyplace except on a deco reg. They are not just as good as a mk25 + s600 combo whatsoever. Also, I have not experienced this "scubapro" creep concept at all. The finickiest regs I have actually ever tried to deal with a hog sealed diaphragms.