Opinions on Inline Regulator Shutoff Valves for SideMount Diving?

[SlugLife]

The one use case that comes to mind for normal stages is for decompression stages: Power up the regulator on the surface, breathe from it, then close the inline shutoff valve.

That's my thought as well. I don't need these yet, but might as well add them to my stash of hardware.

The most valid point made here. Installing flow stops is very dangerous and should not be done unless you know the down stream effects or have a good reason for it.

Your second stage is essential an OPV so if you block it off and do not have an actual OPV installed on your first stage you have just created a potential hose bomb.

I acquired an OPV with that equipment-lot I mentioned. If I do use these for some reason (later), I'll make sure to also install the OPV.

 

[rjack321]

I acquired an OPV with that equipment-lot I mentioned. If I do use these for some reason (later), I'll make sure to also install the OPV.

OPVs are one of the least reliable bits of scuba kit period. Adding a flow stop, to add an OPV is making a mess from something which was previously simple.

 

[sprockjohnson]

I'm not a great fan of the inline shutoff valves, however- I did put one on my octo that's on a bungee around my neck for use while scootering. I found the regulator liked to freeflow while underway no matter which angle I tried to position it in. I could probably just tighten up the seat/ detune it but the valve was a simple fix for a regulator I have never had to actually use. I would never put one on both second stages for overpressure reasons stated in previous posts.

 

[grantctobin]

I'm not a great fan of the inline shutoff valves, however- I did put one on my octo that's on a bungee around my neck for use while scootering. I found the regulator liked to freeflow while underway no matter which angle I tried to position it in. I could probably just tighten up the seat/ detune it but the valve was a simple fix for a regulator I have never had to actually use. I would never put one on both second stages for overpressure reasons stated in previous posts.

Let’s add a step into the process of using the ONLY regulator that has to work when you need it.

 

[Bigbella]

OPVs are one of the least reliable bits of scuba kit period. Adding a flow stop, to add an OPV is making a mess from something which was previously simple.

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 . . .

 

[grantctobin]

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 generally rebuilt annually).

To the OP's original point, I have 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 . . .

That is on a Poseidon and different. Do you use OPVs that are externally screwed into an LP port? I, too, have never had an issue with the integral OPVs. The external ones are bad enough that I keep five in the spares kit and one in my wet notes, despite not having any on my unit

 

[SlugLife]

That is on a Poseidon and different. Do you use OPVs that are externally screwed into an LP port? I, too, have never had an issue with the integral OPVs. The external ones are bad enough that I keep five in the spares kit and one in my wet notes, despite not having any on my unit

Perhaps it's an issue of brand then, if you feel it necessary to have so many spares? Alternatively, perhaps the regulator's IP is too high, so it's blowing, not because it failed, but because it did it's job?

 

[sprockjohnson]

Let’s add a step into the process of using the ONLY regulator that has to work when you need it.

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?

 

[grantctobin]

Perhaps it's an issue of brand then, if you feel it necessary to have so many spares? Alternatively, perhaps the regulator's IP is too high, so it's blowing, not because it failed, but because it did it's job?

No, none of the above.

 

[Bigbella]

That is on a Poseidon and different. Do you use OPVs that are externally screwed into an LP port? I, too, have never had an issue with the integral OPVs. The external ones are bad enough that I keep five in the spares kit and one in my wet notes, despite not having any on my unit

Yes, Poseidon actually offers external 14 bar OPVs (both G 1/8 and UNF 3/8 versions), like those you mentioned, for older model first stages -- and I have a couple mounted on older Cyklons with modern hoses.

So far, so good . . .