Partially used sorb

Joseph Grech · 16th May 2005, 21:09

If there are two more hours to go for a scrubber, how long would you keep this sorb stored for the next dive or dives?

***caveseeker7*** · 16th May 2005, 22:41

Depends on the cannister. In a Ray I'd toss immediately, in a PRISM 3-4 weeks, double bagged and dated.

Pawel · 17th May 2005, 09:56

I'd keep it for up to a month, but only for a short, nice and easy dive. NEVER EVER REPACK THE SCRUBBER! Always keep undisturbed sorb in the scrubber canister, sealed from air. I usually keep in the unit with negative pressure test - believe it or not, my rebreather holds the pressure for this long

. I just take the O2 sensors out of the loop. However, if I am going to have a challanging dive (and most of my dives are) I'd always put fresh sorb and chuck half-used or even 1/3 used sorb out. It may be a waste, but that's what I do

.

Cheers,

Pawel

Joseph Grech · 17th May 2005, 10:49

Pawel, do you use all the remaining time of the sorb ? All this beceause I have an OC buddy and our dives are usually of 60 - 90 minutes. My scrubber should give time for 3 hours, so what would you suggest use all the remaining time ?

Pawel · 17th May 2005, 11:42

Quote: (Originally Posted by Joseph Grech)

Pawel, do you use all the remaining time of the sorb ? All this beceause I have an OC buddy and our dives are usually of 60 - 90 minutes. My scrubber should give time for 3 hours, so what would you suggest use all the remaining time ?

Greetings Joseph,

Difficult to say. What is the scrubber? How much confidence do you have in saying "should"? Do you have any hard data on the scrubber performance? What depth? What is the water temperature? What is your exercise rate? Currents? etc...
I managed to kill a 4h rated scrubber in less than 90 minutes in a single dive

. Most people don't push their breathers this much. The state of the art scrubber I use now would last minimum 3h at maximum exertion rate and most adverse conditions and probably about 6h on a nice and easy tropical reef dive (it takes only 2.0kg of sorb).

Also, I never do a simple sum of time on the scrubber.

Firstly, on repetitive dives that involve storage I take ~30% safety margin, which would be 2 hours cumulative time out of specified 3 hour capacity. This is to account for ventilation of the exposed scrubber when I clean the unit and dry the sensors.

Secondly, I do not use time to measure the sorb usage. I measure the usage of scrubber in liters of O2 used. This is more accurate method than measuring the time, although I am suprised not many people practice it. For example, if I used 50 bar from 1.5L tank, it would be 75L of O2. I know the capacity, performance and characteristics of the scrubber because it was kindly provided to me by the manufacturer

. Based on this data I know I can use up to 200L of O2 on a single load in any conditions and the scrubber will perform safely regardless of the rate of metabolising O2.

Cheers,

Pawel
www.AliensOfTheSea.com/HDTV

TechBlue · 17th May 2005, 12:04

Quote: (Originally Posted by Pawel)

Greetings Joseph,

I managed to kill a 4h rated scrubber in less than 90 minutes in a single dive

. Most people don't push their breathers this much. The state of the art scrubber I use now would last minimum 3h at maximum exertion rate and most adverse conditions and probably about 6h on a nice and easy tropical reef dive (it takes only 2.0kg of sorb)

Cheers,

Pawel
www.AliensOfTheSea.com/HDTV

Pawel,

Care to share the information on your state of the art scrubber? Pics would be very cool

Cheers,

Chris

Pawel · 17th May 2005, 12:20

Quote: (Originally Posted by TechBlue)

Care to share the information on your state of the art scrubber? Pics would be very cool

Greetings Chris,

Picture 1
Picture 2
Picture 3

Cheers,

Pawel

Joseph Grech · 17th May 2005, 13:57

It is a home made rebreather. Internal dimensions as the inspiration with an extra fill of sorb 2.8 Kg.

lizardland · 17th May 2005, 15:29

The Canadian DCIEM did research into this for Canadian Forces rebreathers to minimise the time being wasted prepping units i.e. to see if they could be prepped in advance and stored rather than each time they were required for use.

They did various tests, unused scrubbers, partially used scrubbers, etc., and basically what they found was that as long as the Rebreather it was stored in was holding pressure whilst in storage then scrubber performance would not be compromised. Their tests were based on 10 days of storage but their conclusions IIRC were that longer storage could be done. They were storing in positive pressure state.

Duncan Price · 17th May 2005, 16:24

Quote: (Originally Posted by lizardland)

.....They did various tests, unused scrubbers, partially used scrubbers, etc., and basically what they found was that as long as the Rebreather it was stored in was holding pressure whilst in storage then scrubber performance would not be compromised. Their tests were based on 10 days of storage but their conclusions IIRC were that longer storage could be done. They were storing in positive pressure state.

I prepped one of my D5's for a dive in at the end of January which didn't happen. Left it sealed and took it for a dive at the beginning of April. Only spent an hour on it so I've left it like it is for use again in another two months.

I did clean the hoses, C/L and mounthpiece. The O2 cells are out and the ports blocked - it holds +ve and -ve pressure.

Your milage may vary.

16th May 2005, 21:09	#1 (permalink)
Joseph Grech Joseph Grech Current Rebreather/s: Azimuth Other Rebreather/s: Azimuth Join Date: Mar 2005 Location: Malta Posts: 104	Partially used sorb If there are two more hours to go for a scrubber, how long would you keep this sorb stored for the next dive or dives?
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16th May 2005, 22:41	#2 (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	Depends on the cannister. In a Ray I'd toss immediately, in a PRISM 3-4 weeks, double bagged and dated. __________________ 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.!"
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17th May 2005, 09:56	#3 (permalink)
Pawel New Member Current Rebreather/s: Other Rebreather/s: Join Date: Apr 2005 Location: Sydney, Australia Posts: 68	I'd keep it for up to a month, but only for a short, nice and easy dive. NEVER EVER REPACK THE SCRUBBER! Always keep undisturbed sorb in the scrubber canister, sealed from air. I usually keep in the unit with negative pressure test - believe it or not, my rebreather holds the pressure for this long . I just take the O2 sensors out of the loop. However, if I am going to have a challanging dive (and most of my dives are) I'd always put fresh sorb and chuck half-used or even 1/3 used sorb out. It may be a waste, but that's what I do . Cheers, Pawel
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17th May 2005, 10:49	#4 (permalink)
Joseph Grech Joseph Grech Current Rebreather/s: Azimuth Other Rebreather/s: Azimuth Join Date: Mar 2005 Location: Malta Posts: 104	Pawel, do you use all the remaining time of the sorb ? All this beceause I have an OC buddy and our dives are usually of 60 - 90 minutes. My scrubber should give time for 3 hours, so what would you suggest use all the remaining time ?
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17th May 2005, 11:42	#5 (permalink)
Pawel New Member Current Rebreather/s: Other Rebreather/s: Join Date: Apr 2005 Location: Sydney, Australia Posts: 68	Quote: (Originally Posted by Joseph Grech) Pawel, do you use all the remaining time of the sorb ? All this beceause I have an OC buddy and our dives are usually of 60 - 90 minutes. My scrubber should give time for 3 hours, so what would you suggest use all the remaining time ? Greetings Joseph, Difficult to say. What is the scrubber? How much confidence do you have in saying "should"? Do you have any hard data on the scrubber performance? What depth? What is the water temperature? What is your exercise rate? Currents? etc... I managed to kill a 4h rated scrubber in less than 90 minutes in a single dive . Most people don't push their breathers this much. The state of the art scrubber I use now would last minimum 3h at maximum exertion rate and most adverse conditions and probably about 6h on a nice and easy tropical reef dive (it takes only 2.0kg of sorb). Also, I never do a simple sum of time on the scrubber. Firstly, on repetitive dives that involve storage I take ~30% safety margin, which would be 2 hours cumulative time out of specified 3 hour capacity. This is to account for ventilation of the exposed scrubber when I clean the unit and dry the sensors. Secondly, I do not use time to measure the sorb usage. I measure the usage of scrubber in liters of O2 used. This is more accurate method than measuring the time, although I am suprised not many people practice it. For example, if I used 50 bar from 1.5L tank, it would be 75L of O2. I know the capacity, performance and characteristics of the scrubber because it was kindly provided to me by the manufacturer . Based on this data I know I can use up to 200L of O2 on a single load in any conditions and the scrubber will perform safely regardless of the rate of metabolising O2. Cheers, Pawel www.AliensOfTheSea.com/HDTV
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17th May 2005, 12:04	#6 (permalink)
TechBlue RebreatherWorld Sponsor Current Rebreather/s: Inspiration Classic Classic Kiss Other CCR Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Megalodon Optima Other CCR Join Date: Apr 2005 Location: Costa del Sol, Spain Posts: 212	Quote: (Originally Posted by Pawel) Greetings Joseph, I managed to kill a 4h rated scrubber in less than 90 minutes in a single dive . Most people don't push their breathers this much. The state of the art scrubber I use now would last minimum 3h at maximum exertion rate and most adverse conditions and probably about 6h on a nice and easy tropical reef dive (it takes only 2.0kg of sorb) Cheers, Pawel www.AliensOfTheSea.com/HDTV Pawel, Care to share the information on your state of the art scrubber? Pics would be very cool Cheers, Chris __________________ Cheers, Chris www.tech-blue.com The site dedicated to Rebreather and Technical diving "We only sell what we dive"
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17th May 2005, 13:57	#8 (permalink)
Joseph Grech Joseph Grech Current Rebreather/s: Azimuth Other Rebreather/s: Azimuth Join Date: Mar 2005 Location: Malta Posts: 104	It is a home made rebreather. Internal dimensions as the inspiration with an extra fill of sorb 2.8 Kg.
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17th May 2005, 15:29	#9 (permalink)
lizardland Yak Current Rebreather/s: MK 15.X Home Build Other Rebreather/s: Classic Kiss Home Build Join Date: Mar 2005 Location: North... Posts: 1,301	The Canadian DCIEM did research into this for Canadian Forces rebreathers to minimise the time being wasted prepping units i.e. to see if they could be prepped in advance and stored rather than each time they were required for use. They did various tests, unused scrubbers, partially used scrubbers, etc., and basically what they found was that as long as the Rebreather it was stored in was holding pressure whilst in storage then scrubber performance would not be compromised. Their tests were based on 10 days of storage but their conclusions IIRC were that longer storage could be done. They were storing in positive pressure state.
(Offline)

17th May 2005, 16:24	#10 (permalink)
Duncan Price Sump Monster Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Feb 2005 Location: Wells, Somerset, UK Posts: 335	Quote: (Originally Posted by lizardland) .....They did various tests, unused scrubbers, partially used scrubbers, etc., and basically what they found was that as long as the Rebreather it was stored in was holding pressure whilst in storage then scrubber performance would not be compromised. Their tests were based on 10 days of storage but their conclusions IIRC were that longer storage could be done. They were storing in positive pressure state. I prepped one of my D5's for a dive in at the end of January which didn't happen. Left it sealed and took it for a dive at the beginning of April. Only spent an hour on it so I've left it like it is for use again in another two months. I did clean the hoses, C/L and mounthpiece. The O2 cells are out and the ports blocked - it holds +ve and -ve pressure. Your milage may vary.
(Offline)

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