Valve/manifold procedures "in the real world"

[MXGratefulDiver]

The sequence I was taught is:

1. Isolate

2. Bubble check (visual/hands)

3. SPG check (dropping/stable)

4. Diagnosis based on 2 & 3

5. Post shutdown as required by diagnosis

Can you do SPG diagnosis without isolating first?

How am I not advocating diagnosis?

You obviously don't agree with the sequence, that's okay - maybe you'll convince me to change my procedure to a superior one, if so great & TIA

This is degenerating into a typical "how many angels can dance on the head of a pin" type discussion. FWIW - I was taught the "right post first" method for doing valve drills. However, I was also taught that the purpose of valve drills is to teach you muscle memory and to help you train how to respond promptly and smoothly to an emergency ... rather than to follow some standard sequence under every possible condition.

In the real world, if I can hear bubbles coming from my left side, I'm reaching for that valve first ... because that's most likely where the problem is.

Just like any other problem ... the key is to THINK first, analyze the problem based on the symptoms, and react accordingly ... rather than just following some procedure you learned as a means of developing a skill.

... Bob (Grateful Diver)

 

[RTodd]

The sequence I was taught is:

1. Isolate

2. Bubble check (visual/hands)

3. SPG check (dropping/stable)

4. Diagnosis based on 2 & 3

5. Post shutdown as required by diagnosis

Can you do SPG diagnosis without isolating first?

How am I not advocating diagnosis?

You obviously don't agree with the sequence, that's okay - maybe you'll convince me to change my procedure to a superior one, if so great & TIA

Bob nailed this, but since I read the thread I have to add another reason why isolate first is stupid. If you are losing so much gas that your spg is going to tell you something meaningful, there is no need to isolate in the first place. An initial diagnosis will tell you which post to close with that much gas loss. If, there is that much gas coming from behind my head and I still can't tell (highly, highly unlikely) real world answer is that I would start shutting down both posts while getting teammate assistance. In this extreme example, assuming the right post reg is working, I can crack it to get gas or open it back up if the problem stops once left post is closed and purged.

For a very long time, whether an isolator was even necessary was debated in the pre-DIR naming days. When I took my cave class from JJ, he didn't have one. Of course, he had some other stuff that would get him lynched as a stroke today as well.

 

[TSandM]

What really comes out of a discussion like this is the importance of being able to reach and manipulate your valves EASILY and QUICKLY. I posted a thread about this HERE a while back -- When my husband actually had a freeflow, he was struggling with getting the valve closed, all the while losing gas.

There are two strategies for addressing a massive and unidentifiable source of gas loss behind your head. There are arguments in favor of each. In fact, if you are anywhere where people have mobility (IOW not in a restriction), a massive gas loss should bring your buddies to your side even faster than your signal does. If I come to my teammate and he's in the process of closing the wrong post, I'm going to tell him that! Too often, these discussions seem to assume that one is alone and must manage the entire problem by oneself, which should never be the case in the DIR world.

 

[cos]

.... Too often, these discussions seem to assume that one is alone and must manage the entire problem by oneself, which should never be the case in the DIR world.

Zero visibility touch contact, single file passing through restrictions, incapacitated buddy are 3 off the top of my head that are in the DIR world. In all advanced training I have been taught to be self sufficient and comfortable in the self-sufficiency. There is a huge team component to diving however ultimately you are responsible for youself.

 

[AndyNZ]

In all advanced training I have been taught to be self sufficient and comfortable in the self-sufficiency. There is a huge team component to diving however ultimately you are responsible for youself.

I have to agree with this sentiment. I admire (and aspire to) the wonderful ideal of the unified team that is always acting together as slick, well oiled machine. But I'm also enough of a realist to understand that this ideal state can, and no doubt does, break down at times.

 

[johnkendall]

But in the OPs hypothetical there is no team.

So "most of the time" you end up with more gas than you need (more than 1/3ds and a team with additional gas around you) and on "rare occassions" you die (less than 1/3, alone and you donŽ´t make it out)...

Whenever Im not sure (like willing to bet my life on it or with reserves in form of team or time/gas from my turn-around) I would isolate first but thats not "the dir answer"...

And in my first answer we now have no fingers and a shark around who's gained a meal.

For you to have lost enough gas not to be able to have got out, you need to have lost more than 1/3 of your total starting gas, as well as loosing your team, and not picked the correct post, and then isolated really slowly. I'd suggest that if it takes more than about 30seconds to close a post, listen, and isolate you need to practice more.

HTH

John

 

[TSandM]

Zero vis, touch contact, and you blow a burst disc? You're having a bad day. Same with incapacitated buddy and massive gas loss. We really don't plan for two major failures (at least that's what I've been taught). Yes, you could hit the ceiling in a long restriction and crack a first stage -- I know that happened to Danny -- and that's why we need to be fast at shutdowns.

I think the bottom line is that there are good arguments to be made for both approaches. Having not had a massive gas loss behind me, I really don't know how easy it is to localize the side. All the leaks I've had to deal with were pretty easily identified, and they were slow, so there was lots of time to futz around.

 

[grazie42]

Too often, these discussions seem to assume that one is alone and must manage the entire problem by oneself, which should never be the case in the DIR world.

Zero vis, touch contact, and you blow a burst disc? You're having a bad day. Same with incapacitated buddy and massive gas loss. We really don't plan for two major failures (at least that's what I've been taught).

I know you didnt mean it that way but talking about how things "should" be when discussing incident responses seems very unproductive (if things were as they "should" you wouldnt have an issue to respond to in the first place)

I thought the reason we didnt plan for two major failiures was that it is generally agreed that the benefit of doing so doesent outweigh the "cost". In this case though, the only "cost" of closing the isolator first is losing gas that you dont need in the very rare cases, as everyone seems to agree, where the gass loss is both great and hard to diagnose. Or you are alone. The benefit is surviving even bad days of diving. In this case I have a hard time seeing how the benefit isnt greater than the cost.

I agree that the instances were that benefit would accrue are very uncommon. The point is that youd be alive after the dive, or not, depending on your strategy...

Still not DIR though...

 

[lamont]

This topic has to be on my top 5 most hated DIR topics of all time.

There really is an excessive amount of threads in the archives here and on other boards which debate this subject ad nauseum.

Since the discussion seemed to have regained a relatively even keel, I'll keep the thread open, but keep in mind when you post that you're very unlikely to convince anyone of anything on this topic... You definitely aren't going to change what GUE teaches.

And if I have a burst disk go in my first 200 cave dives, I'll just be happy to get out of there alive... I'll let you know afterward if I went for the post or the isolator first, if I can remember...

 

[Tortuga68]

Thanks everyone for your most informative posts and discussion I have no further questions, Your Honour