Using back mount doubles as single tanks

[Nick_Radov]

How about adding in, the actual dive,

the sequence is to check all valves, when running out of air or breathing hard????

During the dive, what matters,

That was already added in. GUE protocols call for doing a complete flow check whenever you might be unsure of the state of any of your valves. That includes after completing any sort of failure troubleshooting (real or drill), or bumping into any object that could have caused a valve to roll off.

 

[rob.mwpropane]

That was already added in. GUE prior

No rebuttal? I am genuinely curious what your thoughts are (if you've had time to read the thread).

Instead of citing what GUE does let's look at this another way. What purposed does an isolator serve? To prevent loss of gas in the event that an o ring extrudes from one tank, or I guess catastrophic damage occurs to a valve.

How many times has that happened? Realistically? Are we absolutely certain an isolator is needed? It's ok to question this stuff then just blindly following some dogma. This is just the technical forum, not DIR. We're allowed to have open discussions here

 

[Twiny]

No rebuttal? I am genuinely curious what your thoughts are (if you've had time to read the thread).

Instead of citing what GUE does let's look at this another way. What purposed does an isolator serve? To prevent loss of gas in the event that an o ring extrudes from one tank, or I guess catastrophic damage occurs to a valve.

How many times has that happened? Realistically? Are we absolutely certain an isolator is needed? It's ok to question this stuff then just blindly following some dogma. This is just the technical forum, not DIR. We're allowed to have open discussions here

As a solo diver, I love my isolator : in case of any gas leak I won't even try to shut down any first stage, prodecure that might result in too much loss of time/gas. Just by closing the isolator quickly in all cases, I know that 50% of my gas is preserved and it is enough to finish my dive safely according to my gas planning. Once the isolator valve is closed (easy fix) I can go further in the valve drills if not too narked but not under stress

 

[rhwestfall]

So if using ID, and depending on having 2 working regs (buddy breathing is now taboo), do you then use/carry 4 second stages? Two on each tank?

 

[Twiny]

So if using ID, and depending on having 2 working regs (buddy breathing is now taboo), do you then use/carry 4 second stages? Two on each tank?

When diving twinset, you just need 1 long hose and 1 short hose. Total is 2 second stages. Same for decos : 1 second stage per tank

 

[rob.mwpropane]

When diving twinset, you just need 1 long hose and 1 short hose. Total is 2 second stages. Same for decos : 1 second stage per tank

I like @rhwestfall math better though. 4 is better then 2?

 

[Underwater Tourist]

As a solo diver [....] Just by closing the isolator quickly in all cases, I know that 50% of my gas is preserved

I just would like to mention that diving IDs will ensure that 50% of your gas will always be preserved and you don't need to close anything

Since you dive solo, could be a fun set up to try

 

[PfcAJ]

No rebuttal? I am genuinely curious what your thoughts are (if you've had time to read the thread).

Instead of citing what GUE does let's look at this another way. What purposed does an isolator serve? To prevent loss of gas in the event that an o ring extrudes from one tank, or I guess catastrophic damage occurs to a valve.

How many times has that happened? Realistically? Are we absolutely certain an isolator is needed? It's ok to question this stuff then just blindly following some dogma. This is just the technical forum, not DIR. We're allowed to have open discussions here

Burst disk, tank neck, crossbar orings, knob break off with leak.

I am aware of at least two instances of burst disks leaking in-water post ceiling contact.

I am aware of numerous instances of knob break offs or stem shearing rendering knob unusable. Precariously close to a situation where you can lose all your gas pretty quick.

Isolators require management. It is unlikely that you will need one. It is unlikely that you’ll need a long hose, too. But man if you need it, you REALLY need it.

 

[Twiny]

I just would like to mention that diving IDs will ensure that 50% of your gas will always be preserved and you don't need to close anything

Since you dive solo, could be a fun set up to try

Hi, yes you are right but having the possibility to recover all my gas, after a full shut down valve drill, still remains better. Having to swap regs and to check 2 spgs sucks and anyway all rental twinsets are manifolded in Asia.

 

[crofrog]

That was already added in. GUE protocols call for doing a complete flow check whenever you might be unsure of the state of any of your valves. That includes after completing any sort of failure troubleshooting (real or drill), or bumping into any object that could have caused a valve to roll off.

and every 15 minutes according to the SOPs