Is it worth fitting front hose protectors

Divechick · 21st April 2005, 19:43

Quote: (Originally Posted by ROB DAVIE)

Paul,

It is not really required to pick one method over another. As long as you can see the results of the negative pressure check (i.e. either kink, accordion, or crumple) clearly.

Rob

P.S.--I prefer "kinky", but that's just my desire, so to speak!

On the Meg, the hoses are so rigid that when you conduct the negative pressure check you can't see any change in the state of the hose at all. Instead you just suck the counterlungs flat and check they don't change in volume. Hose covers wouldn't make any difference.

Pierre Farrugia · 21st April 2005, 21:19

I dive an Insp. and for the negative test I suck all air in but never succeeded in crushing a hose, but then when I open the mouth piece I can hear the air being sucked in. Is this normal or all the Insp. divers crush their hoses?

Padowan · 21st April 2005, 21:25

Quote: (Originally Posted by Pierre Farrugia)

I dive an Insp. and for the negative test I suck all air in but never succeeded in crushing a hose, but then when I open the mouth piece I can hear the air being sucked in. Is this normal or all the Insp. divers crush their hoses?

What I do to help me crush the hose on the negative test is to pull the hose straight while sucking. Then when the hose contracts on the corrugations, it adds to the negative pressure holding the test. I can get the whole hose crushed on one side (the exhale side funnily enough) with no problems. Getting it to keep it crushed is nore tricky!!

Drmike · 22nd April 2005, 07:07

Quote: (Originally Posted by Pierre Farrugia)

I dive an Insp. and for the negative test I suck all air in but never succeeded in crushing a hose

Er I think most people manually crush the hose whilst sucking a vacuum and then close the mouthpiece and check to see it remains crushed! LOL

I never managed to hold any kind of vacuum on my YBOD - too many damn O rings everywhere!

I find the volume of the Wooomph! sound is a far better indicator as to strength of vacuum than a crushed hose un-crushing is.

ROB DAVIE · 22nd April 2005, 07:13

Quote: (Originally Posted by Divechick)

On the Meg, the hoses are so rigid that when you conduct the negative pressure check you can't see any change in the state of the hose at all. Instead you just suck the counterlungs flat and check they don't change in volume. Hose covers wouldn't make any difference.

Sarah,

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

Cheers!

Rob

***jradomski*** · 22nd April 2005, 08:42

Quote: (Originally Posted by Drmike)

Er I think most people manually crush the hose whilst sucking a vacuum and then close the mouthpiece and check to see it remains crushed! LOL

I never managed to hold any kind of vacuum on my YBOD - too many damn O rings everywhere!

I find the volume of the Wooomph! sound is a far better indicator as to strength of vacuum than a crushed hose un-crushing is.

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...

***jradomski*** · 22nd April 2005, 08:44

Quote: (Originally Posted by Divechick)

On the Meg, the hoses are so rigid that when you conduct the negative pressure check you can't see any change in the state of the hose at all. Instead you just suck the counterlungs flat and check they don't change in volume. Hose covers wouldn't make any difference.

What you can notice on a Meg is the hose sagging.. When you have a good vacuum, the hose is pretty tight (when hanging down), when you loose vacuum it sags lower..

On the neoprene lungs you can really see a change..

decoweenie · 22nd April 2005, 11:54

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...

dive2dive2000 · 22nd April 2005, 14:31

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...

Do you disconnect your ADV, or do you do a shorter test?

Martin

decoweenie · 22nd April 2005, 17:28

Quote: (Originally Posted by dive2dive2000)

Do you disconnect your ADV, or do you do a shorter test?

I can't isolate my ADV since it is part of the loop. I do 30-second negative test, definitely not more than 1-minute.

IMHO, the loop either seals or not, so anything more than 1 minute just means that you need to lube some o-rings somewhere in the loop as the leakage is very minimal.

Then again, "what works for me might not work for others" (whatever that suppose to mean)...

21st April 2005, 19:43	#11 (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) Paul, It is not really required to pick one method over another. As long as you can see the results of the negative pressure check (i.e. either kink, accordion, or crumple) clearly. Rob P.S.--I prefer "kinky", but that's just my desire, so to speak! On the Meg, the hoses are so rigid that when you conduct the negative pressure check you can't see any change in the state of the hose at all. Instead you just suck the counterlungs flat and check they don't change in volume. Hose covers wouldn't make any difference.
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21st April 2005, 21:19	#12 (permalink)
Pierre Farrugia Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Malta Posts: 636	I dive an Insp. and for the negative test I suck all air in but never succeeded in crushing a hose, but then when I open the mouth piece I can hear the air being sucked in. Is this normal or all the Insp. divers crush their hoses? __________________ Pierre Farrugia My wife told me " If you don't quit diving I'm going to leave you" My reply " God, I'll miss you" www.atlam.org www.divemed.com
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21st April 2005, 21:25	#13 (permalink)
Padowan Proper Boffin Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: Kent, UK. Posts: 518	Quote: (Originally Posted by Pierre Farrugia) I dive an Insp. and for the negative test I suck all air in but never succeeded in crushing a hose, but then when I open the mouth piece I can hear the air being sucked in. Is this normal or all the Insp. divers crush their hoses? What I do to help me crush the hose on the negative test is to pull the hose straight while sucking. Then when the hose contracts on the corrugations, it adds to the negative pressure holding the test. I can get the whole hose crushed on one side (the exhale side funnily enough) with no problems. Getting it to keep it crushed is nore tricky!! __________________ Padowan The future's bright, the future's Yellow .....for now padowan.net - Latest Video: Scapa Flow Rebreather Diving
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22nd April 2005, 07:07	#14 (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: 3,165	Quote: (Originally Posted by Pierre Farrugia) I dive an Insp. and for the negative test I suck all air in but never succeeded in crushing a hose Er I think most people manually crush the hose whilst sucking a vacuum and then close the mouthpiece and check to see it remains crushed! LOL I never managed to hold any kind of vacuum on my YBOD - too many damn O rings everywhere! I find the volume of the Wooomph! sound is a far better indicator as to strength of vacuum than a crushed hose un-crushing is.
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22nd April 2005, 07:13	#15 (permalink)
ROB DAVIE Administrator Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Feb 2005 Location: HOUSTON, REPUBLIC OF TEJAS Posts: 1,120	Quote: (Originally Posted by Divechick) On the Meg, the hoses are so rigid that when you conduct the negative pressure check you can't see any change in the state of the hose at all. Instead you just suck the counterlungs flat and check they don't change in volume. Hose covers wouldn't make any difference. Sarah, Although we haven't met, I am sure you wouldn't look anywhere near as nice with flat "lungs"! Cheers! Rob __________________ [SIZE=2]"CC Rebreathers will become a viable part of tech diving [U]WHEN PIGS FLY[/U]!!"--GI3[/SIZE]
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22nd April 2005, 08:42	#16 (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: 2,899	Quote: (Originally Posted by Drmike) Er I think most people manually crush the hose whilst sucking a vacuum and then close the mouthpiece and check to see it remains crushed! LOL I never managed to hold any kind of vacuum on my YBOD - too many damn O rings everywhere! I find the volume of the Wooomph! sound is a far better indicator as to strength of vacuum than a crushed hose un-crushing is. 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... __________________ 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.
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22nd April 2005, 08:44	#17 (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: 2,899	Quote: (Originally Posted by Divechick) On the Meg, the hoses are so rigid that when you conduct the negative pressure check you can't see any change in the state of the hose at all. Instead you just suck the counterlungs flat and check they don't change in volume. Hose covers wouldn't make any difference. What you can notice on a Meg is the hose sagging.. When you have a good vacuum, the hose is pretty tight (when hanging down), when you loose vacuum it sags lower.. On the neoprene lungs you can really see a change.. __________________ 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.
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22nd April 2005, 11:54	#18 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,510	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...
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22nd April 2005, 14:31	#19 (permalink)
dive2dive2000 PRISM DIVER & LUVIN IT! Current Rebreather/s: Prism Topaz Other Rebreather/s: Join Date: Feb 2005 Location: Long Island, NY Posts: 788	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... Do you disconnect your ADV, or do you do a shorter test? Martin
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22nd April 2005, 17:28	#20 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,510	Quote: (Originally Posted by dive2dive2000) Do you disconnect your ADV, or do you do a shorter test? I can't isolate my ADV since it is part of the loop. I do 30-second negative test, definitely not more than 1-minute. IMHO, the loop either seals or not, so anything more than 1 minute just means that you need to lube some o-rings somewhere in the loop as the leakage is very minimal. Then again, "what works for me might not work for others" (whatever that suppose to mean)...
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