Quick release on second stage

[Mcswain30]

Hey all. I’m a relatively new diver, I’ve done 12 or 14 dives and researched A LOT!!! When I did my open water cert. the toughest part for me was sipping the air coming out of a stuck second stage and it was a horrible feeling and got me thinking… which leads to my question/statement:
I’ve been thinking a lot about putting a quick disconnect on my second stage so in the event of getting stuck open I can disconnect and put in my octo and safety ascend.
I know that a stuck valve is a very rare issue, but my thought is safety first.
Please let me know your thoughts/comments.

 

[rhwestfall]

Don't do it!

 

[Wibble]

I’ve been thinking a lot about putting a quick disconnect on my second stage so in the event of getting stuck open I can disconnect and put in my octo and safety ascend.

IMPORTANT... A standard BCD connector won't be able to deliver sufficient gas at depth to provide the volume for a stressed diver, especially with carbon dioxide issues, e.g. puffing like a steam train. You need to use other types of quick disconnect connectors such as QC6s which allow far greater flow.

BUT, assuming you're diving a single tank recreational type configuration with a single cylinder, single first stage with two second stages, when one of the second stages freeflows. You should be able to handle the emergency by aborting the dive, ascending immediately whilst breathing from that regulator AND you should have your buddy with you who should be ascending/aborting the dive with you and will be able to give you their octopus/reserve second stage should you run out of air/nitrox.

"Technical" divers will have two cylinders with two first stages each with one second stage. They will do a lot of training to be able to quickly and efficiently shut down the offending first stage by turning off the appropriate valve. Hopefully the reg will stop freeflowing and any ice buildup will then melt; so you can turn the valve back on and the freeflow will stop. If it doesn't stop, then you will keep that valve closed and abort the dive breathing from the backup regulator.

People do not have quick disconnects on their regulators; valves are used for that.


(There's a little more detail in reality, the above is an overview).

 

[inquis]

Several better options, in my view:

• Learn to feather the valve on your tank. Start learning this at the surface in case you screw it up.
• Switch to your buddy's regulator
• Carry a pony if buddy's air may not be usable

 

[jmcgilroy]

I'm assuming that you were using a rental reg from the dive shop doing your certification. A lot of these have seen some use/abuse. A well-tuned and maintained reg should be the first answer. I have an extreme cold water reg that uses a shut-off at the inlet of the second stage should I get a free-flow due to icing but other than that, I'd go back to my first point.

 

[RyanT]

Don't.

 

[Belzelbub]

I'm assuming that you were using a rental reg from the dive shop doing your certification. A lot of these have seen some use/abuse. A well-tuned and maintained reg should be the first answer.

This. Lots of shop regs have a hard life. Their performance is not typical of what you should expect.

A high quality and well cared for reg will likely not have this happen. Certainly not frequently enough to put a disconnect in line. My daughter’s reg is around 20 years old. It’s been well cared for all that time. It also has venturi Control and breathing adjustment knobs that can help to prevent or stop freeflows.

 

[Wibble]

A quick reminder here might help.

Assuming a regulator is free flowing, how long does it take to empty the tank?

It’s worth measuring if it really bothers you.

 

[stiebs]

Pretty sure OP was referring to a simulated free flow drill, and not implying an actual free flow.

It's an extremely rare occurence, especially in rec diving, and certainly not a reason to use a quick connect.

The exercise is more about showing that when things go wrong, there is more often than not an alternative to immediately shooting to the surface.

 

[Wibble]

Freeflows are more common than hoses breaking. Definitely in cold weather where things freeze.