Bit of info about doubles for a technical noob :)

[Superlyte27]

Ok... well, lets dive into this a bit more (pun intended).

You are diving and your buddy has taken that turn around the bend ahead of you, he's not paying too much attention, but you have a serious issue coming from behind you. You can't tell if it's a hose break, an o-ring at a hose on your first stage, a tank o-ring, burst disk, whatever. Your buddy hasn't even noticed you are signalling like crazy. Which valve do you twist first? Me personally, if I can't quickly determine where the leak is, I'm shutting down the isolator.

 

[PfcAJ]

If I really can't tell, I'll shut down the right post. Either one of two things will happen: The leak will stop, or it won't. If it doesn't, I know one thing that it isn't and I shut down the isolator. Either way, the gas is still leaking, but if I shut down a post, I've narrowed down the problem. From there I'd reopen the right post and breath that while shutting the left post. Once again, it will stop or it won't. Failures of things like tank orings, burst disks and isolator o-rings are a lot more uncommon than reg issues, so I'll start there.

Its going to take a bit of time to completely drain the tanks (regardless of where the leak is from) and between me an my buddy, we have more than enough reserve to get out/up.

 

[TSandM]

If I really can't tell, I'm shutting the right post, because that regulator gets the most use and parts in it were moving that might fail. I can do that quickly, because I had to learn to in order to pass my classes.

But here's the important point -- while I'm doing it, I'm SIGNALING MY TEAM. Before I've even finished closing that post, it's likely I'll have a teammate looking at what's happening, and he can SEE it. If I'm closing the wrong thing, he'll tell me, and probably move in and start doing the right thing. Yes, if I'm in a tight restriction and something goes, I have to solve it all by myself -- but again I can do that fast, and I'm carrying a lot of extra gas, and so are the other two on my team.

 

[ajduplessis]

This is how I do my valve drill/fault finding !!

-Purge backup - make sure it works!!
-Shutdown both isolation and right post using both hands (one move)- This is important to save as much gas as you can (if there is a problem with isolation) and shorten time lapsed.
-Breath down primary, listen for problems/bubbles, switch to backup
-Open right post
-Purge primary - make sure it works!!!
-Shutdown left post
-Breath down backup, listen for problems/bubbles, switch to primary
Open left post
Open isolation

 

[LiteHedded]

This is how I do my valve drill/fault finding !!

-Purge backup - make sure it works!!
-Shutdown both isolation and right post using both hands (one move)- This is important to save as much gas as you can (if there is a problem with isolation) and shorten time lapsed.
-Breath down primary, listen for problems/bubbles, switch to backup
-Open right post
-Purge primary - make sure it works!!!
-Shutdown left post
-Breath down backup, listen for problems/bubbles, switch to primary
Open left post
Open isolation

the problem with shutting them down both at the same time is that you are unable to signal your team.

 

[ucfdiver]

the problem with shutting them down both at the same time is that you are unable to signal your team.

Makes your regs breathe harder, too

 

[LiteHedded]

Makes your regs breathe harder, too

i mean the isolator and the right post. not both posts

 

[rjack321]

I'm shutting down whichever post seems to be the side which is leaking. If it stops great, if it doesn't I'm shutting down the isolator.

Shutting the isolator saves gas only if the failure is a manifold, burst disk or neck ring.
Shutting the offending post saves gas only if the failure is the DIN -oring or reg.

In the one failure I have had on doubles, the fault was the DIN oring coming unseated. In the multiple stage bottle reg failures I have seen the reg cover has come off and LP port hose Oring have failed.

 

[ajduplessis]

the problem with shutting them down both at the same time is that you are unable to signal your team.

Primary objective is to save as much gas as possible. The rest is all secondary.

 

[ajduplessis]

I'm shutting down whichever post seems to be the side which is leaking. If it stops great, if it doesn't I'm shutting down the isolator.

Shutting the isolator saves gas only if the failure is a manifold, burst disk or neck ring.
Shutting the offending post saves gas only if the failure is the DIN -oring or reg.

In the one failure I have had on doubles, the fault was the DIN oring coming unseated. In the multiple stage bottle reg failures I have seen the reg cover has come off and LP port hose Oring have failed.

The problem is that 99% of the time you will not know where the issue is.