Why isn't there a tank valve-open marking?

[BRT]

Depending on the depth you're looking at, I'm not sure that actually works. I'd have to do a test if I ever get to dive deep-ish (100' +), but I wouldn't be surprised if you can have it open "enough for the needle not to move, not enough for you to get air at depth".

Bet you can't.

 

[Dan]

Depending on the depth you're looking at, I'm not sure that actually works. I'd have to do a test if I ever get to dive deep-ish (100' +), but I wouldn't be surprised if you can have it open "enough for the needle not to move, not enough for you to get air at depth".

You don't want to monkey around at 100'+ deep.

The most important thing in my book is to turn the valve all the way open & check the pressure gauge, BEFORE you jump into the water. It happened a couple times in my 550+ dives when I noticed the pressure was reading less than 1500 psig during a week-long liveaboard trip. The dang compressor man skipped / forgot to refill my tank for the next dive in 4 dives / day diving trip. Things can get pretty hectic in a full boat & in the middle of the day, right about lunch time.

I get the habit of checking the pressure gauge, before & throughout the dive, telling my dive buddy of when I get half a tank (time out sign) & 750 psig (fist sign). That makes him / her check his / hers to do the same to me.

 

[diver0008]

...universal labeling standard to show which way to turn a valve on?

All valves close clockwise. Just like at home in your kitchen or bathroom.

Not hard to remember, espcecially if your life depends on it.

For those less mechanically inclined, the valve is closed when you attach your regulator (obviously), so just turn it the only way it will.

If you are going to go underwater with life-sustaining equipment, it is highly advisable to know how to use it.

 

[AfterDark]

As someone mentioned there are left hand valves that work the opposite for SM. However I would think that the operation of these valves is part of SM training.

I'm guessing here but I think that's so both valves "feel" like they are turning in the same direction when mounted correctly in the SM configuration.

 

[Nemrod]

I always back my valves off a little from full open. Been doing it that way nearly five decades, see no reason not to continue to do so. I am also going to gently blow the water off of the weather cap before I put it back on my regulator, been doing that for nearly five decades and see no reason to stop doing that either.

N

 

[Caveeagle]

As someone mentioned there are left hand valves that work the opposite for SM. However I would think that the operation of these valves is part of SM training.

I'm guessing here but I think that's so both valves "feel" like they are turning in the same direction when mounted correctly in the SM configuration.

The only "Left Hand" valve that I have seen still open/close in the normal way. They just have the knob on the opposite side of the valve. Just like like a set of manifold valves with the cross-over removed.

 

[Dan]

It's a simple check. No need any sign. If you can't turn gently counter-clockwise and the gauge shows some pressure, that means it is wide open.

If you don't know which way to turn it on, you shouldn't go diving, take a less dangerous hobby.

 

[Caveeagle]

It's a simple check. No need any sign. If you can't turn gently counter-clockwise and the gauge shows some pressure, that means it is wide open.

If you don't know which way to turn it on, you shouldn't go diving, take a less dangerous hobby.

I agree there is no need for a sign or markings. I think there is a greater issue here with valve management and the risk of beginning a dive with a valve that's not 100% open.

There was a thread here this year where a diver did a "roll off the side" entry and had a major issue with 'no air'. The details were not all that clear, but somehow his 1st stage partially fell off when the boat crew was pulling him back on the boat. From my read of the situation, it sure sounded like someone on the crew had closed his valve. In any case, I don't like anyone touching my valves, and want a 100% physical confirmation of valve position before I enter the water.

 

[divad]

All valves close clockwise. Just like at home in your kitchen or bathroom.

Kitchen and bathroom valves come in different configurations. Both-clockwise is rare on separate hot and cold valves.

 

[diver0008]

Kitchen and bathroom valves come in different configurations. Both-clockwise is rare on separate hot and cold valves.

Right you are.

I suppose it's just one of those things that's become instinctual.

Like which way to turn the valve on a diving tank.