TDI Valve Drill sequence?

[Mark Chase]

Originally Posted by Brian of Aquanauts

So to everyone out there that isolates first, if one of your regs started freeflowing and you can see it, would you really isolate first?

Yes because its instinctive.

How did this thread get on to isolate or right pos shut downs? I thought it was discussing the rights and wrongs of a specific drill?

Anyway:

I don't understand this bit about "you don't loose much gas and "21lpm"

Loads of times I have hit the water and had a stage reg free flow on the surface. I have located the valve (easy with a stage) and done the 10 turns to shut the damed thing off and lost 60bar out of a 7 in the process.

I have had regs free flow on the boat and standing in front of the damed thing i shut down and I seem to have lost 20bar or more? Is it just me? Haven't others experienced this.

I cant do easy shutdowns. I have bought a bigger more flexible suit I bought a DUI under suit and later on a MT Santi undersuit and i have had the rig checked and double checked. I just struggle to shut down quickly.
Whack on a couple of stages and things get worse.

QED i go for the quick option of isolate first in two turns. I cant have my main valves on two turns they would drop off in performance as the pressure dropped. So they are fully open.

I have actually had to abort shutting down many times due to excruciating cramp in my hands. I have flooded my suit due to neck seal failure doing shut downs as well. All bad things to happen. A two turn isolation that guarantees me at least the remaining gas in one cylinder is therefor the right choice for me.

Its a system that will work for any one QED its the better system IMHO.

People who can shut down with great dexterity and speed will never understand and they have the good fortune to be able to minimize the problems/ risks of the right post first option.

Fortunately my tanks are the right way up these days so it no longer an issue.

ATB

Mark Chase

[Paul r h]

Originally Posted by Mal Bridgeman

My own perspective is that if you've fixed the problem then there is no compusion to end the dive. If you are still having fun then why abort? One would have the option at least.
Mal

Sorry but i think until someone has actually experienced a real life situation,irrespective as to whether the fault was fixed,you are not going to be STILL HAVING FUN,try 80mtrs down and you get gas pissing out from the left post,problem is an easy fix,half a turn on the DIN,my buddy sure as heck was not up for more fun.

Paul

[Mal Bridgeman]

Originally Posted by Paul r h

Sorry but i think until someone has actually experienced a real life situation,irrespective as to whether the fault was fixed,you are not going to be STILL HAVING FUN,try 80mtrs down and you get gas pissing out from the left post,problem is an easy fix,half a turn on the DIN,my buddy sure as heck was not up for more fun.

Paul

Paul,

I did say *if* .... for most people 80m is not fun even with fully operational kit, so it all depends on your perspective. The point I was trying to make was that you have an option .... I have had second stage free flows which have settled down and the dive has continued .... but not @ 80 m

Hope that clarifies
Mal

[Paul r h]

Originally Posted by Mal Bridgeman

Paul,

I did say *if* .... for most people 80m is not fun even with fully operational kit, so it all depends on your perspective. The point I was trying to make was that you have an option .... I have had second stage free flows which have settled down and the dive has continued .... but not @ 80 m

Hope that clarifies
Mal

Clarified Mal

Paul.

[Bob Cooper]

Originally Posted by Mark Chase

Loads of times I have hit the water and had a stage reg free flow on the surface. I have located the valve (easy with a stage) and done the 10 turns to shut the damed thing off and lost 60bar out of a 7 in the process.

So, why did you have the stage turned on..?

[Garf]

Originally Posted by Bob Cooper

So, why did you have the stage turned on..?

lol. Good question. If you charge the reg and then turn it off it's somewhat less likely to freeflow when you jump in

[Janos]

Originally Posted by Bob Cooper

So, why did you have the stage turned on..?

Well some people insist on diving Open Circuit and it's only courteous to leave their bailout switched on...

Janos

[Janos]

Reading this thread (and phew it's a long one) but once again Mark Powell has shone the cold light of common sense on the argument.

Except that he's missing that with inverted tanks it's possible to isolate and shut the primary post simultaneously. Well you have two hands after all...

Janos

[Brian of Aquanauts]

Originally Posted by Janos

Except that he's missing that with inverted tanks it's possible to isolate and shut the primary post simultaneously. Well you have two hands after all...

Janos

Is that exclusive to twin-verts?

[Bob Cooper]

Originally Posted by Janos

Well some people insist on diving Open Circuit and it's only courteous to leave their bailout switched on...

Sorry, I don't get that. Surely, any gas you are not breathing should be turned off?

Bob