Importance of CO2 and scrubber life sensors

[Seameadow]

Question for the more experienced CCR divers in this thread. How common is channeling if you are compulsive about packing?

I mean, I have had mushroom valve failures (on a build check, not on a dive), and I overbreathed once as mentioned upthread. But I really spend a lot of time packing my scrubber, hitting it with a rubber mallet, tightening it, hitting it, tightening it more, etc... I rarely keep a scrubber from one weekend to the next, even if I don't have that much time on it.

Is that something that you guys worry about?

Never experienced it. Went from AP, to JJ and have a T-Reb and Triton as well, so axial and radial scrubbers. I have over-worked a scrubber, sure but never experienced channeling.

That said I am also pedantic on packing it properly and damping it down.

 

[Tassi Devil Diver]

From what you're saying, though, do I understand correctly that 1) each scrubber in the Revo dual uses an independent temp stick; 2) the scrubbers flow in series (from scrubber A to Scrubber B); and thus 3) by monitoring whether "Scrubber B" is reacting to CO2 before "Scrubber A" is exhausted, one can determine if "Scrubber A" is improperly permitting CO2 to pass through the absorbent? If so, that seems to be a significant development, and might provide the extra "gut check" reference that I was hoping to see. Of course, this doesn't solve problems associated with overbreathing the loop/reg, but that problem exists on OC as well (and is somewhat self-limiting as compared to a scrubber failure).

Correct and not only that the rEvo RMS via a very nifty algorithm will provide a remaining scrubber time for cycling of scrubber canisters and a total scrubber time.

As someone seriously considering a rEvo down the read, lets change that to: "Channelling is not such an issue for the first of the rEvo dual scrubbers"

Should the second scrubber canister (bottom) suffer from channeling this will be picked up following a canister cycle, when it is moved into the the first scrubber canister position (top) and a fresh canister is placed into the second position (bottom) catching the channeling CO2 as I described above.

Personally I think the risk of channeling through packing of rEvo caster is very low, a few hand taps, tighten down the retaining nut if there is no rattling sound while shaking the canister after packing then good to go. No need for hitting with a rubber mallet or anything like that.

 

[kensuf]

Question for the more experienced CCR divers in this thread. How common is channeling if you are compulsive about packing?

I mean, I have had mushroom valve failures (on a build check, not on a dive), and I overbreathed once as mentioned upthread. But I really spend a lot of time packing my scrubber, hitting it with a rubber mallet, tightening it, hitting it, tightening it more, etc... I rarely keep a scrubber from one weekend to the next, even if I don't have that much time on it.

Is that something that you guys worry about?

I'm a neophyte with only about 1300 hours on the loop. I don't worry about channeling.

Mushroom valves? Yeah, that's a problem I've seen multiple times. Usually caused by getting some debris in the mouthpiece.

Breakthrough from exceeding the scrubber limits? Seen that too. Usually caused by going on repetitive deep dives.

Channeling, per say? Not at all.

 

[mr_v]

Question for the more experienced CCR divers in this thread. How common is channeling if you are compulsive about packing?

I mean, I have had mushroom valve failures (on a build check, not on a dive), and I overbreathed once as mentioned upthread. But I really spend a lot of time packing my scrubber, hitting it with a rubber mallet, tightening it, hitting it, tightening it more, etc... I rarely keep a scrubber from one weekend to the next, even if I don't have that much time on it.

Is that something that you guys worry about?

I'd be more concerned with damaging the canister by hitting it with a mallet ;-)

I tap as I fill. Then I shake the canister and if I hear nothing, it is good to go.

 

[doctormike]

I'd be more concerned with damaging the canister by hitting it with a mallet ;-)

I tap as I fill. Then I shake the canister and if I hear nothing, it is good to go.

The mallet works great....! Just gotta have a deft touch...

I used to just slap the sides. I would tighten the top, slap it, and then I would be able to tighten it more. I find that the mallet works better for that.

I mean, channeling is pretty unlikely if you pack with care and use new sorb. I don't know if the tighter pack that I'm getting by doing this is a net positive (reducing channeling) or a negative (increasing WOB). Maybe the mallet caused my CO2 hit?