Homebuild BOV Idea

Scott

A BOV/ADV, with very very little modifications? -

Heres my idea.....

First...visualize... a complete *normal* dsv, such as that of the dolphin... mouthpiece is facing left, the normally up portion is facing down. to open the dsv the stick is forward, to close it stick is up (i think, I dont have one to hold yet)..

Second, visualize a normal second stage regulator.. mouthpiece up, diaphragm down, exaust tee up and right.

Third DSV mouthpiece and OC Reg mouthpiece join together..

Fourth, a spring increases the pressure required to open the OC Reg exhaust valve..

DSV open, breathing in and out goes through rebreather loop/lungs , pressure isnt enough to activate OC reg unless lungs bottom out..

DSV closed, breath in through OC reg, out through the OC exhaust, which has a *slight* increase in WOB due to spring..

Adjust exhaust tee for cosmetics and direction...

Thoughts?




-Scott

heigo

Looks like you have alot of dead space. Not so good for CO2.

__________________
P3

Scott

That was the only thing I was concerned about.... but being at a right angle to normal flow, I don't think much gas interaction will occur between the flow and the internal volume of the regulator...

Further... if it's an adjustable 2nd stage, the venturi could be turned to further reduce the interaction....

diver1369

Scott:

I see you're still exercising your active imagination (that's a good thing...)

In theory, your idea would decrease both the bulk and the piece count (failure point count) associated with the BOV. As usual, the devil is in the details - how well the various pieces could be made to come together (and stay together) and how stable the 'tune' of the second stage would remain over time.

Without a positive mechanical 'switch-over', a lot would depend on the tune of the reg. Given that the normal mode of operation of a second stage is to supply a lot more air a lot more quickly than we have come to expect from the loop, the second stage would have to be operating well outside of its normal operating range to avoid supplying gas when it is not needed. I suspect that might require more than just replacing a spring. Maybe a reg technician on here could give us further valuable insight into that aspect.

Another thing to think about is the distance from mouth to DSV. Right now, my DSV is right at my mouth, with no appreciable stand-off distance. The second stage would require some stand off, and that might result in some additional lateral force vectors that your lips and teeth would have to control. Over the course of a multi-hour dive, that additional strain on your mouth might become an issue.

If you machine it up, try it out on short dives first...



best,

john