Valve Drill Logistics

[texdiveguy]

Isolate the problem as much as possible. If you can identify which side the bubbles are coming from and turn off that post, if the bubbles don't stop, then go for the isolator, and have your buddy check it out. If it's determined by your buddy to be non-fixable then thumb the dive. .... That would probably be my general run down as I think most likely it would be a problem with a regulator more so than a tank o-ring.

This sounds all and good...but its best to simply shut down the isolator first....in doing so many times you will feel the location of the gas loose and then you can address that then....but by shutting down the isolator valve first you have gone a long way to protect your remaining gas supply....and always re-opening it last after the issues have been addressed.

Also the buddy looking and assisting is fine after the diver has first attempted to take corrective actions....and in many cases the diver might not have a buddy as he/she may be diving solo so its even more important to close off the isolator first.

I for one am not overly concerned with what the TDI//GUE//DSAT/ect. text book says on the proper format for valve drills, you have to take the basics and learn from diving/experience ....in my persl. case if it matters any, my technical instructor/TDI taught shutting the isolator down first in all situations.

 

[mania]

As it was explained to me, the valve drill is an exercise in reaching and manipulating the valves. It's not meant to be a troubleshooting procedure or a response to a failure.

But the point of the drill is to be able to shut down valves when failure occurs.
In fact I have been tought different procedure:
for me full drill is like this:
right post off
breath the primary regulator till the end then change to back up.
right post on
left post off
breath the back up till the end switch to primary
left post on
isolator off
isolator on

And if there is any failure I first shut down isolator to save gas.

mania

 

[willardj]

The thing is if you shut the isolator. Just looking at your pressure gauge will tell you what valve it is. If it's dropping it's the left post, if not it's the right. (If it's a major leak) I can see where you are coming from as well. It is more than likely be a Reg. problem.

Another thing most people react the same way they train. So if you train( R iso L) You are more than likely react that way. Just a thought.

 

[do it easy]

GUE teaches you to try to localize the source of gas loss -- You can turn your head back and forth, or even reach back and try to feel the bubbles. If you can localize, shut that post. If you can't localize, you start with right post, because it's the most likely source of the problem. If bubbles don't stop, you isolate. Of course, the whole time, you've been signalling your team that you have a problem, and honestly, if I get through shutting my right post AND my isolator before I have a teammate looking at the problem and able to communicate with me, my teammate is going to be missing some hide after the dive. If the teammate sees I'm barking up the wrong valve, he can signal me to "hold" and he can come in and fix my error.

If you couldn't localize the failure, would you re-open your manifold before shutting down the left post?

Valve drill has zero to do with bubbles.
its just to practice muscle memory (with no bubbles)

Perhaps we are speaking different languages I think of a valve drill as a tool to use in the event of an unidentifiable leak. This is to be used as a last resort when the obvious is not so obvious.

 

[do it easy]

Another thing most people react the same way they train. So if you train( R iso L) You are more than likely react thay way. Just a thought.

Practice the way you race

 

[limeyx]

This sounds all and good...but its best to simply shut down the isolator first....in doing so many times you will feel the location of the gas loose and then you can address that then....but by shutting down the isolator valve first you have gone a long way to protect your remaining gas supply....and always re-opening it last after the issues have been addressed.

Also the buddy looking and assisting is fine after the diver has first attempted to take corrective actions....and in many cases the diver might not have a buddy as he/she may be diving solo so its even more important to close off the isolator first.

I for one am not overly concerned with what the TDI//GUE//DSAT/ect. text book says on the proper format for valve drills, you have to take the basics and learn from diving/experience ....in my persl. case if it matters any, my technical instructor/TDI taught shutting the isolator down first in all situations.

Well, thanks for your "definitive opinion" Maybe in TDI/DSAT you can go around doing whatever you like after class, but the whole point of GUE is to have a standard way of doing things, and closing the isolator first is not a part of those procedures.

It's also standard GUE practice to have 1-2 buddies available although there is always a possibility you lose a buddy and have a valve problem concurrently.

 

[limeyx]

Perhaps we are speaking different languages I think of a valve drill as a tool to use in the event of an unidentifiable leak. This is to be used as a last resort when the obvious is not so obvious.

Maybe different languages.

Valve drill is (IMO) a drill to make sure you can reach all valves and to associate turning off each post with the appropriate reg (and making sure you know which way is off/on

The "valve drill" that I have learned is right-left on the regs (including argon/stage bottles) in a specific manner.

The "drill" or "procedure" you go through when you hear bubbles is different and necessarily cannot be the same each time due to the many possibilities of bubbles.

If I hear bubbles, I attempt to determine the source and as Lynne has said above, if I cannot, then I assume the right post as it is "most likely"

Closing the isolator first does not really tell you where gas is coming from, and in (according to the right-post-is-most-likely theory) will result in more overall gas actually being lost than going for the right post.

If you close a post (purge 100% or breathe down) and still hear bubbles, then isolate and have a buddy sort you out.

 

[do it easy]

The "drill" or "procedure" you go through when you hear bubbles is different and necessarily cannot be the same each time due to the many possibilities of bubbles.

Yes, this is what I'm addressing, specifically, when the failure is not identifiable.

If I hear bubbles, I attempt to determine the source and as Lynne has said above, if I cannot, then I assume the right post as it is "most likely"

Closing the isolator first does not really tell you where gas is coming from, and in (according to the right-post-is-most-likely theory) will result in more overall gas actually being lost than going for the right post.

Note that I don't suggest closing the isolator first, just not re-opening it until the left post is checked.

If you close a post (purge 100% or breathe down) and still hear bubbles, then isolate and have a buddy sort you out.

Of course, four or six eyes are better than two. Buddies can help as soon as they are able, but why not carry out the procedure to its logical conclusion. I can't accept the last step is "isolate and wait for buddy."

 

[texdiveguy]

Well, thanks for your "definitive opinion" Maybe in TDI/DSAT you can go around doing whatever you like after class, but the whole point of GUE is to have a standard way of doing things, and closing the isolator first is not a part of those procedures.

It's also standard GUE practice to have 1-2 buddies available although there is always a possibility you lose a buddy and have a valve problem concurrently.

Thanks for your 101 on GUE training practices...of which I am fully aware of...just don't follow that way of 'one size' fits all way of doing things. This is not a GUE thread as I read it.

do it easy, this is a good and interesting thread by the way.

 

[matt_unique]

It's interesting to read about the differences in opinion about valve manipulation.

I always close the isolator first....this saves half my gas even if I take no other action (assuming I don't have simultaneous double tank o-ring failure or something).

From that point for a drill I will close the right post, switch to my left reg, then reopen the isolator. To complete the drill I first reopen my right post, close the isolator, shut down my left post, switch to my right reg, then reopen the isolator and left post.

In a real situation I shut down the isolator and pause to try to figure out what side is the culprit. If I can't figure it out I would close the right post and see if the bubbles stop. If they don't, reopen the right post and shut down your left post.

Only once did I have a real situation, I was doing a deco dive on the U853 and my first stage free flowed from icing. In that instance I knew exactly what it was and the cause. I shut down my right post, floated for a few seconds with no other action, then slowly turned my right post back on. The break thawed my first stage and I continued the dive without incident. It was a brand new reg that needed a better adjustment. The adjustment was made and it has not happened since, even in colder water.