Half-packing sorb -- Possible, or deadly?

[jale]

The OP was asking about only half packing a scrubber and that could in theory be done on the sidewinder. Kiss sold a single canister version as a pendulum rebreather to select folks - it was never marketed commercially. I forget the name of that beta unit.

Sheppard?
I built a similar one with a Ray canister and a MSR bag. Good for short stuff but I haven't tried for long dive...

 

[rjack321]

Sheppard?
I built a similar one with a Ray canister and a MSR bag. Good for short stuff but I haven't tried for long dive...

yes! that's what it was called thank you

 

[nikazarenko]

Its not worth it really

 

[Michael Greenberg Manfish]

My choptima uses cartridges which can be used for multi dives or loose sorb.. not to be used on multiple dives. BYPASS is deadly. I dont know much but Jolting/Banging of the unit during site to site transportation or even banging the unit when putting it on and off might cause a resettle or bypass.. I have almost never paid for air in 62 years of diving because I have my own compressors but saving a few bucks on scrubber material.. Thats just friken stupid. Look at the accdent reports.. learn from the mistakes of others.

 

[nadwidny]

I dont know much but Jolting/Banging of the unit during site to site transportation or even banging the unit when putting it on and off might cause a resettle or bypass..

If it's packed properly in the first place transport isn't a problem. Just setting it down and putting it on is a non-issue.

 

[jehle]

Rebreathers go through very specific testing during the design process with a bunch of third party audits to ensure they meet specific guidelines like ISO 9001, FMECA, RESA, etc.
A lot of these test results are available from the manufacture website.
The unit is rated for use under those specific testing scenarios, which includes a fully packed scrubber. I haven't come across any test scenarios of partially packed ones.


Here is an interesting article for a DIY testing kit if you are interested in testing your idea of using partially packed scrubber though:

Low Cost DIY Rebreather Testing: Why and How

Third party rebreather testing is expensive and arguably provides limited data to users and or rebreather builders about scrubber performance. As such, it is rarely used by manufacturers to explore “What-Ifs” i.e., what would be the effect on scrubber duration if we insulated this or modified...

indepthmag.com

 

[mr_v]

If it's packed properly in the first place transport isn't a problem. Just setting it down and putting it on is a non-issue.

That's how you pack sorb tighter. Pack at home. Drive at a spirited speed on country roads to get to a dive site. Open up the sorb canister and add more sorb if there is more room ;-)

 

[Mobulai]

Here is an interesting article for a DIY testing kit if you are interested in testing your idea of using partially packed scrubber though:

Low Cost DIY Rebreather Testing: Why and How

Third party rebreather testing is expensive and arguably provides limited data to users and or rebreather builders about scrubber performance. As such, it is rarely used by manufacturers to explore “What-Ifs” i.e., what would be the effect on scrubber duration if we insulated this or modified...

indepthmag.com

As much as I love the SNORT (I plan to build one myself at some point); the 5k BOM to make it is wasted if it’s just used to determine if I wanna reuse partially used sorb

 

[Michael Greenberg Manfish]

The recent thread about the Dive Talk GO got me thinking... One of that unit's features is a small scrubber. Its limited sorb capacity makes this particular rebreather only suitable for non-expedition-type dives, but for that particular use case, the small scrubber seems reasonable.

Let's assume, then, that a diver has a rebreather with a standard-capacity scrubber (say four or five hours' worth of sorb). This diver has a use case in which they'll be doing a 1.5-hour one-off dive, or maybe two relatively quick dives. The diver doesn't want to go OC, and storing the partially used sorb for later is either impossible or impractical.

Could this diver half-pack the scrubber in their full-size rebreather? And if so, would it necessarily be a bad idea?

NOTE: I'm not gonna do it; I'm just curious.

I use a choptima. One of the things I love is that it can use loose sorb OR an extendair cartridge. The cartridge, as you may know, can be continually used up to the maximum amount of minutes taking into account the temperature and work load. I am changing over to a 30 cf oxygen cylinder back mount from a 13 so that I never put myself into the situation where I can make a BAD decision (diving without enough O2 for unplanned occurances). It is also logistically better and sometimes a big cost saver. Reusing or storing sorb for another time seems totally foolish. Too many divers have died trying to save $10-15 USD. Cartridges are not affected by bouncing around or breakthrough due to channelization. I am only a Newbie however. What is your life worth? There are no stupid questions, but you are showing your inclination to start making bad decisions.. No offence meant.

 

[Michael Greenberg Manfish]

That's how you pack sorb tighter. Pack at home. Drive at a spirited speed on country roads to get to a dive site. Open up the sorb canister and add more sorb if there is more room ;-)

Good Answer.