Opinions on Inline Regulator Shutoff Valves for SideMount Diving?

[SlugLife]

True. It does add a step and a couple extra o-rings but also keeps the regulator usable in my scenario with the freeflow during scootering. Do you have a better suggestion/ solution?

I might have been a little less snarky, if I was to say something similar to what he did.

I might have tried de-tuning the regulator first. It depends on the regulator, but usually you can detune it inside of where the regulator attaches to the hose. All of mine have a flat-head screwdriver adjustment. There's one other style that semi-common which is a hex-wrench if I remember correctly.

That said, if one does have a shut-off installed, and is practiced in using it and switching regulators, I don't see it as a big-deal aside from perhaps a buddy grabbing it. The idea that a scooter might cause frequent freeflow on some regulators makes sense to me. Having a shut-off valve is probably better than losing all your air or ditching the octo.

 

[grantctobin]

True. It does add a step and a couple extra o-rings but also keeps the regulator usable in my scenario with the freeflow during scootering. Do you have a better suggestion/ solution?

Scootering horizontally rather than diagonally? It’s a non issue, even at >250’ a minute. Either it’s tuned improperly or oriented incorrectly.

 

[lowwall]

True. It does add a step and a couple extra o-rings but also keeps the regulator usable in my scenario with the freeflow during scootering. Do you have a better suggestion/ solution?

Detune it until the freeflow stops. If that makes WOB too high, then switch to a different second stage.

 

[rjack321]

I keep hearing this, usually based on second or third hand accounts; yet, in decades of diving, I have never experienced an OPV failure, whether they were a built-in feature of my older (Poseidon) hoses; or, more recently, mounted within the latter-model first stages (which are typically rebuilt annually).

To the OP's original point, I have regularly used shut-off valves and / or manifolds for full-face masks for years, without incident; but I agree that it may just add needless complexity for his purposes . . .

The external ones are horrible. They are a tiny nylon disk held against an orifice by a spring. The nylon falls apart on a regular basis. They also sometimes fail just in storage (probably due to excess summertime heat in the car). Having a handful of them on hand is legit. I have had 3 fail over the years.

 

[lowwall]

This was the topic of the most recent Innerspace Explorer's youtube video. There's nothing in their answer that hasn't been discussed above, but if you're interested...

 

[sprockjohnson]

Scootering horizontally rather than diagonally? It’s a non issue, even at >250’ a minute. Either it’s tuned improperly or oriented incorrectly.

Less helpful.

Detune it until the freeflow stops. If that makes WOB too high, then switch to a different second stage.

Much more helpful. Thank you.

 

[Bigbella]

The external ones are horrible. They are a tiny nylon disk held against an orifice by a spring. The nylon falls apart on a regular basis. They also sometimes fail just in storage (probably due to excess summertime heat in the car). Having a handful of them on hand is legit. I have had 3 fail over the years.

The Poseidon external OPVs have been just fine, though certainly pricey -- and the current ones attached to a couple of my heavily-used Cyklon 300s, are six-plus years old -- and I have far older ones on an Xstream MK3, made well before the addition of its integral OPV . . .

 

[lexvil]

The external ones are horrible. They are a tiny nylon disk held against an orifice by a spring. The nylon falls apart on a regular basis. They also sometimes fail just in storage (probably due to excess summertime heat in the car). Having a handful of them on hand is legit. I have had 3 fail over the years.

Didn’t you just describe a MK2?

 

[rjack321]

The Poseidon external OPVs have been just fine -- and those attached to a couple of my heavily-used Cyklon 300s, are six-plus years old -- and I have even older ones on an Xstream, made well before the addition of an integral OPV . . .

the highland ones are decent, even if they are $35 ish

 

[rjack321]

Didn’t you just describe a MK2?

The mk2 is the exact opposite of an OPV lol
OPV dies after 6 months in a save a dive kit, MK2 survives a nuclear war