Proof that BOV's don't effect -ve pressure tests

pchanning · 1st June 2006, 19:38

Oooff, that went spectacularly wrong.

Firstly, apologies to Mike. I think those that posted are merely trying to get to the root of a problem that you have sufferred, not attack your argument. Tge BOV has prevailed as one of THE safety features for CCR and your experience combined with all sorts of strange musings/ conclusions about these devices on here of late rouses critical interest.

I reasoned that observation mixed with a little piss taking (as you do) would help put a few things in perspective and even out the debate. It obviously came across completely wrong. Once again, I apologise. Some things just don't translate well in this medium.

Anyway, back to figuring out what makes a good BOV...

I'm off to inspect my o-rings!

pchanning · 1st June 2006, 19:53

Quote: (Originally Posted by divetheworld)

Carefully stepping round the toys on the floor.

Paul,
The fact that you havnt changed the 'o' rings on your Divematics might be a good reason why it is so reliable. Perhaps some standard AP DSV users can step in here. When you change the 'o' ring, it does not like to maintain the curve of the barrel and consequently steps out and gets trapped between the barrel and the housing. Ergo, you cant close off the loop without fiddling. How deadly could that be, especially in a situation where your going off loop involuntarily. This settles down quickly with use, but might give you cause to pause. Just a throw away point to keep you safe.

OK, so I'm stepping away from the o-rings now.

Quote: (Originally Posted by divetheworld)

A constructive but critical evaluation of each of the BOV's would be of use.

hear, hear.

Quote: (Originally Posted by divetheworld)

The BOB does have some nice features but they are heavy out of the water... *snip*

I'm strapping a TX100 to mine as we speak - what a beast, I'll have a jaw-line like Desperate Dan

, still it'll breathe like a dream...

Mdemon · 1st June 2006, 20:22

Quote: (Originally Posted by Drmike)

You guys are like a dog with a bone - why so aggressive and pedantic?
....
Now can we drop the attitude?

you know what - just forget it

Blimey! You still sub-clinical from that dip you did??!

Maybe you could tell us which BOV you were using? It would help... I think we're all a bit alarmed at the thought that our shiney bits of life-support equipment may be flawed - I don't think the BOB H will fail in the way you suggest, but yours probably wasn't a BOB H anyway. I hope...

Sorry Mike, but I don't think we're being pedantic or attitude-laden, and certainly not intentionally. Please don't take my posts as meaning to be agressive!

Not so sure about that troublemaker Channing though...

steevke · 1st June 2006, 20:33

Quote: (Originally Posted by pchanning)

I'm strapping a TX100 to mine as we speak - what a beast, I'll have a jaw-line like Desperate Dan

, still it'll breathe like a dream...

Paul, try strapping a 'sepadiver' Eisberg second stage on it (like on the Nemotec & V4TEC). It has the same inner workings as the TX50 series, but the exhaust valve is incorporated in the inhale membrane - this makes it very compact.

Steven

colinicky · 1st June 2006, 20:41

Quote: (Originally Posted by steevke)

Paul, try strapping a 'sepadiver' Eisberg second stage on it (like on the Nemotec & V4TEC). It has the same inner workings as the TX50 series, but the exhaust valve is incorporated in the inhale membrane - this makes it very compact.

Steven

And were could we obtain this please ?

Andy M · 1st June 2006, 21:01

Quote: (Originally Posted by pchanning)

Jeez dude. I sure as heck wouldnt like to swim that thing in a current!

Looks like it would do a good job of removing your teeth if you were decoing on the shot, past the end of slack.

Does it purge every time you look down at your gauges?

steevke · 1st June 2006, 21:14

Quote: (Originally Posted by colinicky)

And were could we obtain this please ?

www.sepadiver.com
But you will need to call them as they are not on the website. Also, on the V4TEC the inner workings are installed in a custom acetal housing. But that is easy to mill/build. It's the plug/housing that's a bit more difficult.

Steven

Drmike · 2nd June 2006, 04:11

Quote: (Originally Posted by Mdemon)

Maybe you could tell us which BOV you were using?

Kirby Morgan (KM48 Nato pod) - o-rings
V4TECH - no o-rings - holds neg (as all non-o-ring designs will IF the 2nd stage is shut off or connected to a closed tank during neg as previously mentioned) [just as you would turn off your adv to do a neg]

Quote: (Originally Posted by Mdemon)

I think we're all a bit alarmed at the thought that our shiney bits of life-support equipment may be flawed - I don't think the BOB H will fail in the way you suggest, but yours probably wasn't a BOB H anyway. I hope...

I dont see why it couldnt. It has the same o-ring layout. I never said it was likely - only that it was possible.

I never said either design was flawed. I fully agree with Brents comments. Just highlighting features not taking a polarised stance on which is better.
Remember the title of this thread which I was responding to - it is a generalisation which is incorrect. Some BOV (non o-ringed ones) can effect a -ve test if the clearance isnt good or the valve isnt well maintained/lubrictaed/cleaned or if the 2nd stage isnt connected or shut off (non oring design). Some o-ring designs can pass a neg when the orings has failed (if the failed o-ring is on the exhaust side and its the inhale o-ring which seals off the 2nd stage when the valve is closed.

In my dive room I have a inspo dsv (o-rings), a MK15.5 DSV (no o-rings), a Boris dsv (no o-rings) a KM48 Nato pod (o-rings) a V4TECH (no-orings)

I trust my life to all of them all give me a neg test (if maintained). But I am aware of the differences/features of o-ring v non o-ring design which is all that I was doing - highlighting the differences. I really wasnt taking a polarized view of one is better or worse - just different.

Quote:

Not so sure about that troublemaker Channing though...

nah were cool

pchanning · 2nd June 2006, 09:16

Quote: (Originally Posted by Mdemon)

Not so sure about that troublemaker Channing though...

tosser

Quote: (Originally Posted by Andy)

Jeez dude. I sure as heck wouldnt like to swim that thing in a current!

Shuttup mate, this is a 'Ming Dynasty' BOV dont cha know

Quote: (Originally Posted by Andy)

Looks like it would do a good job of removing your teeth if you were decoing on the shot, past the end of slack.

LOL - nothing a strap can't cure. OK, so its a big strap.

Quote: (Originally Posted by Andy)

Does it purge every time you look down at your gauges?

No idea yet. However the last reg had a similar orientation and that was alright. I'll let you know.

1st June 2006, 19:38	#21 (permalink)
pchanning PFO free :) Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: fixed! Posts: 454	Re: Proof that BOV's don't effect -ve pressure tests Oooff, that went spectacularly wrong. Firstly, apologies to Mike. I think those that posted are merely trying to get to the root of a problem that you have sufferred, not attack your argument. Tge BOV has prevailed as one of THE safety features for CCR and your experience combined with all sorts of strange musings/ conclusions about these devices on here of late rouses critical interest. I reasoned that observation mixed with a little piss taking (as you do) would help put a few things in perspective and even out the debate. It obviously came across completely wrong. Once again, I apologise. Some things just don't translate well in this medium. Anyway, back to figuring out what makes a good BOV... I'm off to inspect my o-rings! __________________ Cheers Paul The key to enlightenment... is survival.
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1st June 2006, 19:53	#22 (permalink)
pchanning PFO free :) Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: fixed! Posts: 454	Re: Proof that BOV's don't effect -ve pressure tests Quote: (Originally Posted by divetheworld) Carefully stepping round the toys on the floor. Paul, The fact that you havnt changed the 'o' rings on your Divematics might be a good reason why it is so reliable. Perhaps some standard AP DSV users can step in here. When you change the 'o' ring, it does not like to maintain the curve of the barrel and consequently steps out and gets trapped between the barrel and the housing. Ergo, you cant close off the loop without fiddling. How deadly could that be, especially in a situation where your going off loop involuntarily. This settles down quickly with use, but might give you cause to pause. Just a throw away point to keep you safe. OK, so I'm stepping away from the o-rings now. Quote: (Originally Posted by divetheworld) A constructive but critical evaluation of each of the BOV's would be of use. hear, hear. Quote: (Originally Posted by divetheworld) The BOB does have some nice features but they are heavy out of the water... snip I'm strapping a TX100 to mine as we speak - what a beast, I'll have a jaw-line like Desperate Dan , still it'll breathe like a dream... __________________ Cheers Paul The key to enlightenment... is survival. Last edited by pchanning : 1st June 2006 at 19:56.
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1st June 2006, 20:22	#23 (permalink)
Mdemon SiegeEngine II Current Rebreather/s: Inspiration Classic Home Build Other Rebreather/s: Inspiration Classic Home Build Join Date: Feb 2007 Location: SWUK Posts: 1,927	Re: Proof that BOV's don't effect -ve pressure tests Quote: (Originally Posted by Drmike) You guys are like a dog with a bone - why so aggressive and pedantic? .... Now can we drop the attitude? you know what - just forget it Blimey! You still sub-clinical from that dip you did??! Maybe you could tell us which BOV you were using? It would help... I think we're all a bit alarmed at the thought that our shiney bits of life-support equipment may be flawed - I don't think the BOB H will fail in the way you suggest, but yours probably wasn't a BOB H anyway. I hope... Sorry Mike, but I don't think we're being pedantic or attitude-laden, and certainly not intentionally. Please don't take my posts as meaning to be agressive! Not so sure about that troublemaker Channing though... __________________ www.southwestmafia.com "small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!" The WRONG Attitude will get you killed. "Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"
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1st June 2006, 20:33	#24 (permalink)
steevke Custom Title Allowed! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Sport Kiss Join Date: Jul 2005 Location: Belgium Posts: 311	Re: Proof that BOV's don't effect -ve pressure tests Quote: (Originally Posted by pchanning) I'm strapping a TX100 to mine as we speak - what a beast, I'll have a jaw-line like Desperate Dan , still it'll breathe like a dream... Paul, try strapping a 'sepadiver' Eisberg second stage on it (like on the Nemotec & V4TEC). It has the same inner workings as the TX50 series, but the exhaust valve is incorporated in the inhale membrane - this makes it very compact. Steven
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1st June 2006, 20:41	#25 (permalink)
colinicky Custom Title Allowed! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Mar 2005 Location: uk Posts: 667	Re: Proof that BOV's don't effect -ve pressure tests Quote: (Originally Posted by steevke) Paul, try strapping a 'sepadiver' Eisberg second stage on it (like on the Nemotec & V4TEC). It has the same inner workings as the TX50 series, but the exhaust valve is incorporated in the inhale membrane - this makes it very compact. Steven And were could we obtain this please ? __________________ Colin I trust my rebreather completely , I just don't trust the user onwards & downwards
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1st June 2006, 21:01	#26 (permalink)
Andy M Dude Current Rebreather/s: Home Build Other Rebreather/s: Sport Kiss Home Build Join Date: Mar 2005 Location: Cambridge, UK Posts: 424	Re: Proof that BOV's don't effect -ve pressure tests Quote: (Originally Posted by pchanning) Jeez dude. I sure as heck wouldnt like to swim that thing in a current! Looks like it would do a good job of removing your teeth if you were decoing on the shot, past the end of slack. Does it purge every time you look down at your gauges? __________________ Know your PO2 at all times
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1st June 2006, 21:14	#27 (permalink)
steevke Custom Title Allowed! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Sport Kiss Join Date: Jul 2005 Location: Belgium Posts: 311	Re: Proof that BOV's don't effect -ve pressure tests Quote: (Originally Posted by colinicky) And were could we obtain this please ? www.sepadiver.com But you will need to call them as they are not on the website. Also, on the V4TEC the inner workings are installed in a custom acetal housing. But that is easy to mill/build. It's the plug/housing that's a bit more difficult. Steven
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2nd June 2006, 04:11	#28 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,325	Re: Proof that BOV's don't effect -ve pressure tests Quote: (Originally Posted by Mdemon) Maybe you could tell us which BOV you were using? Kirby Morgan (KM48 Nato pod) - o-rings V4TECH - no o-rings - holds neg (as all non-o-ring designs will IF the 2nd stage is shut off or connected to a closed tank during neg as previously mentioned) [just as you would turn off your adv to do a neg] Quote: (Originally Posted by Mdemon) I think we're all a bit alarmed at the thought that our shiney bits of life-support equipment may be flawed - I don't think the BOB H will fail in the way you suggest, but yours probably wasn't a BOB H anyway. I hope... I dont see why it couldnt. It has the same o-ring layout. I never said it was likely - only that it was possible. I never said either design was flawed. I fully agree with Brents comments. Just highlighting features not taking a polarised stance on which is better. Remember the title of this thread which I was responding to - it is a generalisation which is incorrect. Some BOV (non o-ringed ones) can effect a -ve test if the clearance isnt good or the valve isnt well maintained/lubrictaed/cleaned or if the 2nd stage isnt connected or shut off (non oring design). Some o-ring designs can pass a neg when the orings has failed (if the failed o-ring is on the exhaust side and its the inhale o-ring which seals off the 2nd stage when the valve is closed. In my dive room I have a inspo dsv (o-rings), a MK15.5 DSV (no o-rings), a Boris dsv (no o-rings) a KM48 Nato pod (o-rings) a V4TECH (no-orings) I trust my life to all of them all give me a neg test (if maintained). But I am aware of the differences/features of o-ring v non o-ring design which is all that I was doing - highlighting the differences. I really wasnt taking a polarized view of one is better or worse - just different. Quote: Not so sure about that troublemaker Channing though... nah were cool __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment Last edited by Drmike : 2nd June 2006 at 04:24.
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2nd June 2006, 09:16	#29 (permalink)
pchanning PFO free :) Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: fixed! Posts: 454	Re: Proof that BOV's don't effect -ve pressure tests Quote: (Originally Posted by Mdemon) Not so sure about that troublemaker Channing though... tosser Quote: (Originally Posted by Andy) Jeez dude. I sure as heck wouldnt like to swim that thing in a current! Shuttup mate, this is a 'Ming Dynasty' BOV dont cha know Quote: (Originally Posted by Andy) Looks like it would do a good job of removing your teeth if you were decoing on the shot, past the end of slack. LOL - nothing a strap can't cure. OK, so its a big strap. Quote: (Originally Posted by Andy) Does it purge every time you look down at your gauges? No idea yet. However the last reg had a similar orientation and that was alright. I'll let you know. __________________ Cheers Paul The key to enlightenment... is survival. Last edited by pchanning : 2nd June 2006 at 09:24.
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