Stupid question without notice... double tanks

[ozJohnno]

Hi there,
When you are diving doubles, which way do you turn the isolation valve on the manifold to isolate your two cylinders?

I know this is a stupid question but it had been on my mind since I aborted a 30m dive because I could not confidently Identify that my isolation valve was open.

so which way is it to fully open the valve on your manifold.... full anticlockwise or full clockwise

Thanks in advance

Johnno

 

[caruso]

I admit to knowing nothing of manifolds and diving with doubled tanks however I would be willing to bet my bottom dollar that turning the isolation valve clockwise closes the valve and cuts off the flow of gas between the two tanks.

 

[rhwestfall]

Clockwise = close

 

[tursiops]

Same way as on your tanks.

 

[ozJohnno]

Nice one guys thanks for your advice. Even if I had the isolation valve closed I could have simply switched to the reserve regulator, but by this stage I was getting a bit worked up about it and decided that getting worked up about stuff is unsafe and it was better to be safe than sorry, so I signalled to one of my dive buddies (we were a foursome) and slowly headed to the surface.

 

[tursiops]

Do more valve shutdown drills in shallow water, until it is completely muscle-memory automatic which valve to turn which direction in which order....no reason to have to think about it under stress.

 

[ozJohnno]

cheers Tursiops, will do
johnno

 

[Compressor]

Nice one guys thanks for your advice. Even if I had the isolation valve closed I could have simply switched to the reserve regulator, but by this stage I was getting a bit worked up about it and decided that getting worked up about stuff is unsafe and it was better to be safe than sorry, so I signalled to one of my dive buddies (we were a foursome) and slowly headed to the surface.

Yes better be safe than sorry. Routine check list/way of doing things predive is good so when you second guess yourself, you think did I do what I always do? Yes I did but can't exactly remember that part but I know it was not omitted.

 

[runsongas]

righty tighty lefty loosey

 

[Scared Silly]

How can one tell that the isolator is most likely closed?

1. You start the dive with a reading of your SPG
2. Sometime into the dive your SPG is still where it was at the being on the dive.
3. Sometime into the dive you are OOG - isolator was closed, left cylinder was filled, right is cylinder was not.
4. You have an SPG on the left post and a transmitter on the right and the readings do not agree.


FWIW My spouse learn #3 the hard way, though successfully dealt with the issue. She was on her backup by the time I deployed mine to her. The dive was aborted and we had a good debrief, first with ourselves, then the captain, then the filler. The reason there was a discussion with the captain is we aborted the dive so a safety issue. The reason there was a discussion with the filler is they shut the valve off. However, the responsibility was on us to check all valves before the dive - complacency kills. Good education for all.