How open do you keep your iso valve?

[MASS-Diver]

I just finished reading "Fatal Depth," in which the author reports that many people dive with their isolation valve just barely open so that if they have to isolate a tanks they only need to turn the valve a small ammount.

Do you dive like this?

Is it easy to roll a isolation valve shut?

What's the DIR position?

 

[WYDT]

MASS-Diver once bubbled...
I just finished reading "Fatal Depth," in which the author reports that many people dive with their isolation valve just barely open so that if they have to isolate a tanks they only need to turn the valve a small ammount.

Do you dive like this?

Is it easy to roll a isolation valve shut?

What's the DIR position?

Wide F**kin Open - hey to DL!

The only way you will need to actually isolate your tanks is if you loose a burst disk, tank neck o-ring or the isolator itself starts leaking on one side otherwise you just shut off the post that is giving the problem. A situation that would require isolation is very rare and shutting down is very quick and easy if practiced. Leaving the isolator "barely open" is inviting a real problem to occur.

Another "fix" for a non-existant problem.

 

[WreckWriter]

Rob is exactly right. Wide open.

WW

 

[Wendy]

ditto what the guys said....wide open...especially when filling your tanks.

 

[Capt Jim Wyatt]

I have always kept it about half way or less open so a shut down can be done more quickly.

Clearly leaving it barely open could be a problem, but half-way does not seem to me to be a problem.

What trouble is one inviting if the valve is not left wide open?

 

[O-ring]

Only closed if in the middle of a valve drill..

 

[MASS-Diver]

I see, that makes sense.


So, if (for example) your primary reg starts free flowing - you reach for the post and shut it down there (so as to save the air in it), you don't go for the isolation valve first (or even second). So, really being able to reach and shut down each post is just as important to practice (as part of a valve drill) as is working one's isolation valve.

Along the same lines, an even more basic question: how much do you guys open up your tank valves (does how fast you can close them play a role?)?

 

[Capt Jim Wyatt]

The tank valves must be wide open to prevent a restricted orifice at depth.

 

[MASS-Diver]

It's OK to crack them back a little bit though right (1/4 of a turn)?

 

[Capt Jim Wyatt]

I have always closed mine about 1/4 turn back. The reason I do that is so if the valve is bumped it won't jam it in the open position.