Is it worth fitting front hose protectors

decoweenie · 22nd April 2005, 17:33

Quote: (Originally Posted by jptaylor9)

If dil side not pressurised, you'll have less than 1 bar pressure difference across ADV diaphragm. Assuming an interstage pressure on the dil side of 9.5 bar, you'll usually exceed this pressure difference (in opposite direction) for well over 30 mins while diving.

IMHO I'd expect the diaphram to be able to handle this pressure difference!

I think we are seeing how the ADV work differently, or may be our ADV work differently in principle.

On the KISS, the diaphragm is just a barrier between the ambient pressure (water column outside) and the loop pressure (gas you are breathing on the loop). They are suppose to be the same.

If the loop pressure is low, then the diaphragm concaves in and triggers the pin that lets the diluent gas in. Once the pressure differential is equalize, the diaphragm straighten out and stops touching the pin. No more diluent gas coming in.

How does your ADV work, or which unit are you diving ?

***Decodiver*** · 22nd April 2005, 18:36

That is the beauty of the Meg ADV, no diaphragm

Cheers,

Dave Cooper.

***caveseeker7*** · 22nd April 2005, 19:26

Quote: (Originally Posted by Decodiver)

That is the beauty of the Meg ADV, no diaphragm

Doesn't mean you'll get a MiniMeg if you hump it.

***Decodiver*** · 22nd April 2005, 20:09

Quote: (Originally Posted by caveseeker7)

Doesn't mean you'll get a MiniMeg if you hump it.

No but I will be picking up a MiniMeg in February

***jradomski*** · 22nd April 2005, 21:07

Quote: (Originally Posted by decoweenie)

I see some references above that people are holding the negative pressure test over-night or 30 minutes +, etc. So I just to want to point out that if your ADV is part of the loop when you do the test, by holding the negative test so long, you risk damaging the diaphragm of the ADV by over-stretching it...

Phi,
It really de[endson the ADV.. The way its done on the KISS any change in the diaphram will reduce the effectivness of the ADV. Not to knock the kiss but it uses a tilt valve which is very effective bit allows very little variation in the diaphram.. Many other ADVs use a diaphram in the way its used in a normal demand regulator, this alows alot of tollerance...

I'll only do an "overnight" test if I replaced one of the majorcomponentsliek a manual add or T piece.. slow leaks wount be found in a 1 minute test, but will be noticable in a 10-15 minute test.. a 5 minute test will find all but the smallest leaks..

In rgards to the person who saw the neg failwith a flow stopand the tank pressureized there are 2 possibilities, 1 the flow stop is leaking, but more likely there is a minute leak in the manual add this is probably only under pressure..

1st try submerging the manual add in a glass of water and see if you can see anything.. if not try a good leak detection solution (not soapy water) very small leaks require the correct solution.

Divechick · 25th April 2005, 11:35

Quote: (Originally Posted by ROB DAVIE)

Sarah,

Although we haven't met, I am sure you wouldn't look anywhere near as nice with flat "lungs"!

Cheers!

Rob

Well, I'm happy to say I'm not a flat girl!

***Beanie*** · 25th April 2005, 12:05

I have hose protectors on the front nice purple ones to go with my lungs
£3.88 each from AP in whatever colour they have
they may stop doing colours though as this is slowing production down, think my mates have just ordered the last coloured breeathers

***Louby Lou*** · 25th April 2005, 12:33

Quote: (Originally Posted by Beanie)

I have hose protectors on the front nice purple ones to go with my lungs
£3.88 each from AP in whatever colour they have
they may stop doing colours though as this is slowing production down, think my mates have just ordered the last coloured breeathers

That would be your girlfriend and your mate sweetie

Drmike · 26th April 2005, 06:15

Quote: (Originally Posted by jradomski)

Mike the leaks are not generally on the o-rings (remember all the hose fittings have TWO o-rings) its usually around the t-pieces or manual inflators.. The one o-ring that does leak (just because most people do not change it) is the one in the lid that the sensor holder tightens up against, This definately gets flat! On the YBOD you should be able to hold a really tight vacuum.. I know I can hold it over night without any problems...

if you use a bob howell ADV I have seen leaks from it...

I agree the T connector-lung joint is also a PITA for leaks (mine both did)

I also agree that many people can hold vaccum overnight (which I think is overkill and anything more than 1 min is not worth stressing over)

But the fact of the matter is my unit did have o-ring leaks.

Even with double o-rings a hair laying across both o-rings will enable a leak and a badly moulded/dimensioned/finished T piece/connector will allow double o-rings to leak.

***jradomski*** · 26th April 2005, 07:59

Quote: (Originally Posted by Drmike)

Even with double o-rings a hair laying across both o-rings will enable a leak and a badly moulded/dimensioned/finished T piece/connector will allow double o-rings to leak.

I agree with you there.. I was talking more from a perspective that if everything is clean leaks don;t happen often on any of the hose ends.... a malformed tpiece should be replaced, there is no reason for that...

22nd April 2005, 17:33	#21 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,487	Quote: (Originally Posted by jptaylor9) If dil side not pressurised, you'll have less than 1 bar pressure difference across ADV diaphragm. Assuming an interstage pressure on the dil side of 9.5 bar, you'll usually exceed this pressure difference (in opposite direction) for well over 30 mins while diving. IMHO I'd expect the diaphram to be able to handle this pressure difference! I think we are seeing how the ADV work differently, or may be our ADV work differently in principle. On the KISS, the diaphragm is just a barrier between the ambient pressure (water column outside) and the loop pressure (gas you are breathing on the loop). They are suppose to be the same. If the loop pressure is low, then the diaphragm concaves in and triggers the pin that lets the diluent gas in. Once the pressure differential is equalize, the diaphragm straighten out and stops touching the pin. No more diluent gas coming in. How does your ADV work, or which unit are you diving ?
(Offline)

22nd April 2005, 18:36	#22 (permalink)
*Decodiver* Administrator Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jan 2005 Location: Geneva Posts: 2,181	That is the beauty of the Meg ADV, no diaphragm Cheers, Dave Cooper. __________________ CCR/OC Trimix Instructor Trainer CCR Training to Mixed Gas in Switzerland, France, UK & Germany on Megalodon/COPIS-Megalodon/KISS/Sport KISS/Ouroboros/rEvo/Inspiration/Evolution/Sentinel www.zerogravitydiving.com Rebreather World Terms & Conditions
(Offline)

22nd April 2005, 19:26	#23 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,451	Quote: (Originally Posted by Decodiver) That is the beauty of the Meg ADV, no diaphragm Doesn't mean you'll get a MiniMeg if you hump it. __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"
(Offline)

22nd April 2005, 20:09	#24 (permalink)
*Decodiver* Administrator Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jan 2005 Location: Geneva Posts: 2,181	Quote: (Originally Posted by caveseeker7) Doesn't mean you'll get a MiniMeg if you hump it. No but I will be picking up a MiniMeg in February __________________ CCR/OC Trimix Instructor Trainer CCR Training to Mixed Gas in Switzerland, France, UK & Germany on Megalodon/COPIS-Megalodon/KISS/Sport KISS/Ouroboros/rEvo/Inspiration/Evolution/Sentinel www.zerogravitydiving.com Rebreather World Terms & Conditions
(Offline)

22nd April 2005, 21:07	#25 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,004	Quote: (Originally Posted by decoweenie) I see some references above that people are holding the negative pressure test over-night or 30 minutes +, etc. So I just to want to point out that if your ADV is part of the loop when you do the test, by holding the negative test so long, you risk damaging the diaphragm of the ADV by over-stretching it... Phi, It really de[endson the ADV.. The way its done on the KISS any change in the diaphram will reduce the effectivness of the ADV. Not to knock the kiss but it uses a tilt valve which is very effective bit allows very little variation in the diaphram.. Many other ADVs use a diaphram in the way its used in a normal demand regulator, this alows alot of tollerance... I'll only do an "overnight" test if I replaced one of the majorcomponentsliek a manual add or T piece.. slow leaks wount be found in a 1 minute test, but will be noticable in a 10-15 minute test.. a 5 minute test will find all but the smallest leaks.. In rgards to the person who saw the neg failwith a flow stopand the tank pressureized there are 2 possibilities, 1 the flow stop is leaking, but more likely there is a minute leak in the manual add this is probably only under pressure.. 1st try submerging the manual add in a glass of water and see if you can see anything.. if not try a good leak detection solution (not soapy water) very small leaks require the correct solution. __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
(Offline)

25th April 2005, 11:35	#26 (permalink)
Divechick Came down in the last shower of rain Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Feb 2005 Location: London, UK Posts: 53	Quote: (Originally Posted by ROB DAVIE) Sarah, Although we haven't met, I am sure you wouldn't look anywhere near as nice with flat "lungs"! Cheers! Rob Well, I'm happy to say I'm not a flat girl!
(Offline)

25th April 2005, 12:05	#27 (permalink)
*Beanie* give a man an inch....... Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,174	I have hose protectors on the front nice purple ones to go with my lungs £3.88 each from AP in whatever colour they have they may stop doing colours though as this is slowing production down, think my mates have just ordered the last coloured breeathers __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk
(Offline)

25th April 2005, 12:33	#28 (permalink)
*Louby Lou* XLVI WC! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Roman Corinium! Posts: 1,019	Quote: (Originally Posted by Beanie) I have hose protectors on the front nice purple ones to go with my lungs £3.88 each from AP in whatever colour they have they may stop doing colours though as this is slowing production down, think my mates have just ordered the last coloured breeathers That would be your girlfriend and your mate sweetie __________________ Miss Lou x Use of Rebreather World is subject to the Rebreatherworld Terms and Conditions - Please read! Outlaw Divers - Sssh we're diving! You heff vays uff dealink vis zem, oh Miss Rebreather World Admin! - Rob Davie Feb 06
(Offline)

26th April 2005, 06:15	#29 (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	Quote: (Originally Posted by jradomski) Mike the leaks are not generally on the o-rings (remember all the hose fittings have TWO o-rings) its usually around the t-pieces or manual inflators.. The one o-ring that does leak (just because most people do not change it) is the one in the lid that the sensor holder tightens up against, This definately gets flat! On the YBOD you should be able to hold a really tight vacuum.. I know I can hold it over night without any problems... if you use a bob howell ADV I have seen leaks from it... I agree the T connector-lung joint is also a PITA for leaks (mine both did) I also agree that many people can hold vaccum overnight (which I think is overkill and anything more than 1 min is not worth stressing over) But the fact of the matter is my unit did have o-ring leaks. Even with double o-rings a hair laying across both o-rings will enable a leak and a badly moulded/dimensioned/finished T piece/connector will allow double o-rings to leak.
(Offline)

26th April 2005, 07:59	#30 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,004	Quote: (Originally Posted by Drmike) Even with double o-rings a hair laying across both o-rings will enable a leak and a badly moulded/dimensioned/finished T piece/connector will allow double o-rings to leak. I agree with you there.. I was talking more from a perspective that if everything is clean leaks don;t happen often on any of the hose ends.... a malformed tpiece should be replaced, there is no reason for that... __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
(Offline)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode