Standard rental cylinders - right-tank valve in or out?

I've seen some interesting and varied approaches with sidemounting. One variation that caught my attention is the decision to orientate the right-side tank valve-in/reg-inside or valve-out/reg-outside.

Obviously, there are pros and cons to either:

Valve-In means the regulator 1st stage is protected inside the cylinder and routes cleanly. However, the valve handle is now inwards and more difficult to manipulate - also with potential (?) problems with bungee security.

Valve-Out provides simple bungee security and un-fettered access to the valve handle (shut-downs/feathering etc). However, the regulator first stage is now exposed, as are the hoses.

So a poll... which do you use.... and what drives your preference?

I currently use valve in because its what i was taught, but have been playing around a lot and will prob at some point try valve out and see how the hose routing goes for me.

Valve-in. I'm not going to have to manipulate both valves at the same time (i.e. manifolded shutdown), so I can always use my left / both hands.

Paul S:

Valve-in. I'm not going to have to manipulate both valves at the same time (i.e. manifolded shutdown), so I can always use my left / both hands.

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I can see there is some logic in that.

However, my thoughts are that it'd be counter-intuitive to your in-grained responses. Whenever diving with 'proper' sidemount orientated tanks, you'd have to re-adjust to left-hand/left-tank and right-hand/right-tank shut-downs.

As such, the issue of instinctive shut-downs could easily be perceived as an argument for right-cylinder handle out orientation?

in case of Murphy, i vote out for ease and some degree of 'naturalness' for righties (i'm a righty), not sure if this works for lefties though theoretically there should not be lefty set ups?

For me it would be 100% valve inwards and 1st stage facing upwards in all circumstances.

I normally use the wrap style of bungee mounting to it can easily be used for no-mount, not that I do no-mount diving on most dives, I just prefer to have the same configuration for all dives.

Turning a regular valve outwards on the right tank makes wrapping of bungees much harder to achieve and less secure? We normally teach a double wrap (well, one and half wraps) on the left post to avoid these bungee security problems - The attached image shows the double (1.5) wrap on a deco bottle (all my standard tanks at hose have extended stem valves, I wouldn't use a neck clip on a sidemount tank), the other image shows the standard bungee wrap.



If the bungee is wrapped from the inside to the outside the tank will rotate and expose the reg (plus it will tend to fall off if moved to a no-mount position) - the wrap needs to be from the outside to the inside whenever possible. This is one of the main reasons I always prefer a single continuous bungee over two independent bungees.

The main reason for needing to shut down the valve would be a reg or hose failure, turning the reg to face down significantly increases the likelihood of such problems occurring in my opinion as it leaves the 1^st stage and hoses exposed and in a bad location (unless the PADI style forward facing HP hose routing is used, in which case the HP hose will take most of any impact at the crimp point – seems a great idea as the HP hose crimp is practically indestructible and it seems inconceivable that the hose could ever burst at that point).

With an independent sidemount configuration there’s a little more thinking before closing down a valve in either case, I don’t think valve in or valve out would be an issue, plus either hand can still be used and sidemount valves are ridiculously easy to close when compared to back mount.

Karl

PS - It's worth mentioning both photos show the tanks for a left side configuration, not a right side, but the general idea is still the same

Handle out. Although I prefer the 1st stage to be up and protected safety trumps that. I've been in passages where there would be no way to shut down the right side tank if the valve was pointing in. There just isn't enough room from floor to ceiling. Now, if you're not diving passages that tight then it doesn't really matter. I also use loop bungees to secure my tanks so this necessitates the handle being out so there is something to loop around. While I could probably lengthen the loop a bit and run it over a handle routed in, that would also make it more difficult to push the tank forward through a restriction. I recently spent several dives diving a small cave with AL80s just like this and had no issues with having the 1st stage down. I also route the hoses so they are between the tank and my body, not at the bottom of the tank.

I travel with and take my own Right Hand/Left Post Valves to mount on the dive-ops rental AL80's (S80), and just use the standard Left Hand/Right Post Valve supplied by the dive-op for the left tank --so both sidemount tanks have the handwheels facing out and the regulator 1st stages facing up, and the bungies of my Z-system SM Harness thread under the QC6 connections & loop over the handwheels tight, drawing the tank tops up under the armpits. . .

Kevrumbo:

I travel with and take my own Right Hand/Left Post Valves to mount on the dive-ops rental AL80's (S80)

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Yep - that's a good way to go, a pair of extended stem valves shouldn't break the bank

---------- Post added December 20th, 2012 at 03:50 PM ----------

Dive-aholic:

Handle out. Although I prefer the 1st stage to be up and protected safety trumps that. I've been in passages where there would be no way to shut down the right side tank if the valve was pointing in. There just isn't enough room from floor to ceiling.

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I was struggling to visualise this but think I get it now from the posts on the other thread. I'd always expect tanks to be up at armpit level so they are pretty easy to reach whichever way the valve is facing, I see how that would be a problem with tanks mounted much lower down.

It there any specific reason why the tanks are normally so low for steel tanks? Is it related directly to the butt plate door handle locations and tank lengths or is it mainly for easier trimming/balance? Obvious it's not as much of an issue with Aluminium tanks here as the weight is not as much of an issue while most of us tend to mount on a upper or lower harness belt d-ring rather than a butt plate.