Revo BOV questions

[Wibble]

Was a bit fun. Lots of learning points.

Main thing was that when the caustic cocktail hit, the logical brain woke up; literally the first words through my head were "good heavens, a caustic cocktail, bail out now…".

All was fine from that moment forwards. Was breathing from the bottom bailout a bit heavily, stress not hypercapnia — breathing not out of control. Threw up the SMB from the bottom, 49m, then did a simple open circuit ascent with 35 mins of deco including some extra time.

Back on the boat the unit had at least a cupful of milky water and sodden scrubbers. No way they’d be scrubbing any CO2.

Bailout gas consumption was well within planning, rough SAC for deco gas (13 litres/min) higher than OC days, but OK. Lots of gas left in the cylinders.

Not interested in dwelling on what could of happened or what I should have done. All that matters is crap hit the fan and it was dealt with.

Massively positive from the experience. Proved the training and constant practice worked. Pity for the task fixation preventing issue resolution — one of the main learning points.

Hopefully it’ll make me a better diver as a result.

Bailouts topped up. Diving tomorrow.

Oh, have bought the Revo BOV with QC6s. Arriving in a couple of days.

 

[Dsix36]

I was trained to use an absorbant cloth in BOTH lungs and have been doing that was for years. Never a single issue.

 

[Wibble]

I was trained to use an absorbant cloth in BOTH lungs and have been doing that was for years. Never a single issue.

The root cause was the DSV mouthpiece lever being slightly open thus leaking into the loop.

This was exacerbated by me being fixated on the incorrect hypothesis that there was a teaspoon of water and it was my poor clearing skills. Went into a spiral of focusing on the task with increasing frustration and trying ever more aggressive clearing techniques, which drowned out any logical deduction to problem solve.

This was the major lesson. Repeating the same failing attempt to fix it is unlikely to achieve anything other than another failed fix. Stop and reassess the facts.

 

[Wibble]

I was trained to use an absorbant cloth in BOTH lungs and have been doing that was for years. Never a single issue.

Where do you put the cloth in the top lung?

 

[Tracy]

I really would like to know how to do that.

With the absence of a dump in the bottom of the exhale lung or a "pump dump in a sump" after the exhale mushroom valve, I can’t see an official technique. (V. happy for a PM if not a public discussion)

Head down and dil flush will push the water out the top left OPV.

 

[Dsix36]

Where do you put the cloth in the top lung?

I have one that is 12" x 3" that I roll up into a 12 long burrito shape and poke it tight into the bottom of the exhale lung. The smallest little amount will still protrude above the scrubber opening. It has never moved or caused an issue with the lines or ADV

 

[Wibble]

Head down and dil flush will push the water out the top left OPV.

Probably need to roll right and down so the liquid stays in the lung to be ejected through the OPV

Edit...

The exhale lung OPV is next to the exhale loop connection. Head down will need the loop removed from the mouth and held upward to keep the liquid in the lung -- bail out to open circuit? Even after that a lot of water would remain.

 

[cathal]

Probably need to roll right and down so the liquid stays in the lung to be ejected through the OPV

Edit...

The exhale lung OPV is next to the exhale loop connection. Head down will need the loop removed from the mouth and held upward to keep the liquid in the lung -- bail out to open circuit? Even after that a lot of water would remain.

Not that I know, and just a guess, but would the water not leave via the OPV if the ambient pressure in the exhale lung is greater than the external water pressure??

 

[Wibble]

Not that I know, and just a guess, but would the water not leave via the OPV if the ambient pressure in the exhale lung is greater than the external water pressure??

It would, but it would also run down the exhale loop hose, leaving a lot un-cleared.

Maybe the trick is to kink the hose close to the entry point?

Seems like a pool session practice: flood the exhale lung then clear it. But don't stand up vertically when it's lifted out of the pool.

 

[lermontov]

It would, but it would also run down the exhale loop hose, leaving a lot un-cleared.

Maybe the trick is to kink the hose close to the entry point?

Seems like a pool session practice: flood the exhale lung then clear it. But don't stand up vertically when it's lifted out of the pool.

could be an expensive exercise unless you use your old sorb