How important to have same regulator setup for tec

[jgttrey]

I think OP is asking because he knows he has to replace the AirII with a conventional second stage and wants to know if his new second stage needs be same brand and/or model as his current primary second stage.

I think Tbone answered this in his first post. It's desirable but not mandatory.

But, I'll say that you will be doing lots of regulator exchanges and breathing off that new second on a regular basis, so it should be good. Depending on what you're training to do, you are also likely to buy more gear - you'll have more than one first stage for sure. So, you're gonna be buying stuff. You might get better, more complete advice if you tell us more about your current first/second stage and also where you see yourself going in your training.

For example, if you told me you were going sidemount and planning on doing deco, it might be most efficient to use keep your current first stage and second and use them on a stage or deco bottle and then get a dedicated set of regs that configure and route nicely for sidemount.

If you're buying gear anyway, my advice is buy once and buy right.

 

[Diver0001]

I think OP is asking because he knows he has to replace the AirII with a conventional second stage and wants to know if his new second stage needs be same brand and/or model as his current primary second stage.

I think Tbone answered this in his first post. It's desirable but not mandatory.

There is no logic by which identical second stages is desirable or mandatory.

This is like saying that if you wear socks that it is "desirable" for both socks to be the same, but not mandatory. The actual FUNCTION of a sock demands neither of these. Only social convention does.

When we talk about dive gear, the top 10 priorities are

10) function
9) function
8) function
7) function
6) function
5) function
4) function
3) function
2) function
1) what looks good.

... and by the way, given my personality, for many years I actually did NOT match socks. I just took any two random ones out of my drawer that morning and wore those.... even in a professional setting where I was required to wear a suit and tie to cover up the other "creative" aspects of my personality. I've even been known to wear un-matching shoes to work.

Not surprisingly, through most of my history of technical diving, function has won out over form and my gear has seldom "matched". At the moment it actually does but that's also just a random event because I replaced two regulators at the same time and *happened* to replace them with the same make and model.

R..

 

[jgttrey]

There is no logic by which identical second stages is desirable or mandatory.

This is like saying that if you wear socks that it is "desirable" for both socks to be the same, but not mandatory. The actual FUNCTION of a sock demands neither of these. Only social convention does

I commend your iconoclastic fashion sensibility but even if you don't care too much about your sock color, if you lost a black one (and there was a market for single replacements), would you intentionally go buy an orange one to pair up with it?

As to the logic: I prefer to have commonality of service kits and spares, for one thing.

OP is about to buy a new second to go with an existing first/second. He/she is in the market for another second stage with, I assume, similar performance characteristics to the existing second stage. Sure, you could buy another brand, but all things being equal, why do so?

Is it a big deal? No. If OP was looking on some special "deal" on a non-matching second, I'd say go for it. But, that has not been suggested as the situation.

 

[tbone1004]

@Diver0001 one can argue that when you are prioritizing function over all else, you will end up with the same regulators across the board.
If function is reliable and good breathing, why would that give two different regulators?

 

[fullytek]

@Diver0001 one can argue that when you are prioritizing function over all else, you will end up with the same regulators across the board.
If function is reliable and good breathing, why would that give two different regulators?

Why. Because of common mode failure.

An Identical device may fail when exposed to identical conditions.

 

[Magnus Lundstedt]

Why. Because of common mode failure.

An Identical device may fail when exposed to identical conditions.

Then it is better to avoid the one that fails first. ...

I prefere to use regulators that is suitable for the conditions I dive in, and keep them in good service.
And if one fails, its usualy not due to design, its due to some error.

 

[Diver0001]

I commend your iconoclastic fashion sensibility but even if you don't care too much about your sock color, if you lost a black one (and there was a market for single replacements), would you intentionally go buy an orange one to pair up with it?

No, of course not. But I wouldn't intentionally buy a second black sock either. When function is primary, the form is entirely secondary.

As to the logic: I prefer to have commonality of service kits and spares, for one thing.

I don't know why this would matter to you unless you are a registered regulator tech and you service your own gear.

OP is about to buy a new second to go with an existing first/second. He/she is in the market for another second stage with, I assume, similar performance characteristics to the existing second stage. Sure, you could buy another brand, but all things being equal, why do so?

All things being "equal" there would be no reason to, but then we are talking about functionality and not all other stuff.

Is it a big deal? No. If OP was looking on some special "deal" on a non-matching second, I'd say go for it. But, that has not been suggested as the situation.

My own view would be that if all things were indeed "equal" then toss a coin. That said, I do suffer (admittedly irrationally) from a fondness for certain brands and aversion to others, particularly with respect to regulators. In that case, if all things were truly "equal" I admit that I would decide based on emotion.

R..

 

[tbone1004]

Why. Because of common mode failure.

An Identical device may fail when exposed to identical conditions.

except they aren't exposed to identical conditions. May be on separate tanks, one isn't always being used, one sees inherently less cycles since it isn't always in use, etc etc.
Most common regulator failure is HP creep. That is not an exposure failure, it's a use failure. Just because one failed, does not increase the risk of the other failing.
In ice diving, most common failure is an ice block in the second stage which causes freeflow. Just because one failed does not increase the risk of the other failing that hasn't been used. One could argue that the operator error that caused the first will repeat the second, but in that case the regulator chosen was not up to the task at hand. I.e. buy NORSOK approved regs for ice diving, Apeks and Poseidon

 

[Diver0001]

@Diver0001 one can argue that when you are prioritizing function over all else, you will end up with the same regulators across the board.
If function is reliable and good breathing, why would that give two different regulators?

The question isn't about whether or not you would initially choose to buy a mix-matched set. The question is why you would choose to replace a regulator you already had for the singular reason that it happened to look different to the new one....

R..

 

[fullytek]

Absolutely it's better to avoid the failure.

But some times things outside of our control happen . And well one brand of regulator with a diffrent compound seat may be able to handle the conditions well another may not.

Back in my racing days I recall watching as 5 diffrent engines in 5 diffrent race cars all swallow valves within 25 laps of each other. The common link was all engines were built in the same shop to the same spec and delivered just for that one event. However they all were exposed to the same conditions for about the same amount of time .