Question storage time for ready to dive CCR

[phgachoud]

Hey folks, just got my brand new JJ-CCR and after preparing it to dive and ready, I was wondering how much time I can let it ready for dive without creating potential issues, and back from a dive not spending all the scrubber and gases apart from rincing it outside and the loop should I disassemble it completely rince and reassemble it between a few days dives, and if not how many days would you advise?
I know brand new sofnolime 797 is advised but costs here about 50 box a load so I take it 2 times in the water till I run out of the 200min runtime.

 

[mr_v]

Between the dives: disassemble, rinse, and dry.

Your sorb cassette can be in the open for about 28 days at room temperature / moderate humidity before sorb starts losing its potency. Most people will put cassettes in plastic bags.

 

[nicklesshead]

Good read about this topic: Storage of partly used closed-circuit rebreather carbon dioxide absorbent canisters

I try to not let it sit used open for longer than 7 - 10 days.
Within this short times, I do not notice any reduction of performance, I even don’t keep the scrubber in a sealed bag.
But it also depends on the upcoming dives if I change the scrubber or not.

 

[DiveLikeAMuppet]

Before diving:
No clue? Days? If the unit is assembled and DSV closed, nothing will happen. If you keep it assembled for weeks, you might start thinking about some of the o-rings (in the head) getting squished? You might want to re-run part of your checklist to make sure that batteries and so on are still OK?

Clean-up:

Depends on the weather. Ideally, you always take 2 litre bottle with you to do a quick clean after a dive - rinse any lung butter out of your loop and exhale counterlung. The unit will take a week or two of diving in colder climate with just quick cleaning until your loop starts to develop a bit of a taste. Then it's time to disassemble, rinse and disinfect. I generally rinse the loop and both counterlungs after each weekend of diving but that's mainly my storage limitation.

If you dive in hotter climate - be more diligent about rinsing.

Always take your head out to dry the cells.

Scrubber duration:

Official scrubber duration is about 180 minutes. Unofficially - how lucky do you feel? The main problem is moisture loss - so it might be a good idea to wrap the packed scrubber in a plastic bag between dives if it's longer than overnight.

It's common to pack the scrubber once for a weekend of diving for a total duration of 3-4.5 hours, either as four shorter dives or perhaps two longer deco dives. I've dived a single scrubber for 6 hours in a cold local quarry but not very deep and without high workloads, and wouldn't go past 4 hours total on any bigger dives.

A good starting point in terms of scrubber duration is his article: The Secrets of Scrubbers

You could also read the JJ CE report. It's interesting to check the test parameters - the majority of the estimated 180 minutes duration have not been spent at depth...

Keep in mind that you can overbreathe even a fresh scrubber if you work hard(er) at depth. I wouldn't want to be working hard when the scrubber is mostly spent and the active zone is at the every end.

Word of god - JJ manual:

Running time: 180 min with dive profile (40 m), 180 min with dive profile (100 m)
Dive profile: 40 min at 40 m, 5 min at 15 m, 9 m (40 m) for the remaining time
Dive profile: 10 min at 100 m, 1 min at 39 m, 1 min (100 m) at 36 m, 2 min at 33 m, 2 min at 30 m, 2 min at 27 m, 3 min at 24 m, 4 min at 21 m, 4 min at 18 m, 6 min at 15m, 7 min at 12 m, 10 min at 9 m, 6 m for the remaining time

Test parameter: 40l/min air, 1.6l/min CO2,
4°C water temperature
Used diluent: 40 m - Air
100 m - Trimix 11/65

 

[rjack321]

Unless you are using it within a couple days I disassemble, rinse (or sterilize) and dry the head and loop. The scrubber gets a time/date label and goes in a plastic bag.

 

[davehicks]

If I setup my CCR and dive one hour, I will often leave it for a few weeks before doing an additional dive or two an another day. I always rinse the loop and spray in some steramine, and leave that to dry. The head is opened so the cells can dry. I only need to do basic predive checks before heading out again.