Half-packing sorb -- Possible, or deadly?

[stretchthepenn]

What is your life worth? There are no stupid questions, but you are showing your inclination to start making bad decisions.. No offence meant.

Please re-read the original post, note the disclaimer at the end, and attempt to comprehend the vast difference between someone trying to increase their theoretical knowledge and someone looking to justify a crackpot stunt. Offense taken.

 

[kensuf]

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.

When you move to an off-board oxygen source, be sure to lower the IP on your O2 regulator to no more than about 85 psi. The clipper solenoids in the Choptima do not do well with IPs greater than 90 psi and you will burn it out. I've got a good friend that lives in Marathon, who you may know, that had to replace his solenoid two months ago because of doing exactly what you're discussing.

 

[Tracy]

When you move to an off-board oxygen source, be sure to lower the IP on your O2 regulator to no more than about 85 psi. The clipper solenoids in the Choptima do not do well with IPs greater than 90 psi and you will burn it out. I've got a good friend that lives in Marathon, who you may know, that had to replace his solenoid two months ago because of doing exactly what you're discussing.

Better yet, don't lower the IP on the reg, just use the one that comes with the unit and change the hose. Not all regs are stable at lower IPs. Unless you are certain it is, error on the side of caution and use the factory reg.
XT first stages don't have an issue that I am aware of, FTs require a different spring to feed at the lower IP. Without it, they will stop delivering gas at depth.

 

[rjack321]

When you move to an off-board oxygen source, be sure to lower the IP on your O2 regulator to no more than about 85 psi. The clipper solenoids in the Choptima do not do well with IPs greater than 90 psi and you will burn it out. I've got a good friend that lives in Marathon, who you may know, that had to replace his solenoid two months ago because of doing exactly what you're discussing.

Better yet, don't lower the IP on the reg, just use the one that comes with the unit and change the hose. Not all regs are stable at lower IPs. Unless you are certain it is, error on the side of caution and use the factory reg.
XT first stages don't have an issue that I am aware of, FTs require a different spring to feed at the lower IP. Without it, they will stop delivering gas at depth.

For the love of god whyyyyy would DiveRite use a unique low IP solenoid like this when 145psi solenoids are a readily available thing which completely avoids creating all these "special" 1st stage situations. Cause what they heck are you going to do when that 1st fails days from civilization? I imagine it would be a major scramble to get this problem sorted even in someplace like France, Norway, or even Tulum.

 

[Tracy]

For the love of god whyyyyy would DiveRite use a unique low IP solenoid like this when 145psi solenoids are a readily available thing which completely avoids creating all these "special" 1st stage situations. Cause what they heck are you going to do when that 1st fails days from civilization? I imagine it would be a major scramble to get this problem sorted even in someplace like France, Norway, or even Tulum.

The clipper solenoid is more efficient. When they changed to that style, the 9v driving the solenoid last usually a year rather than a couple of months. It is a reliable solenoid, it just needs a lower IP. You can run it on a standard IP, it just doesn't last as long.

 

[Baja Johnny]

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.

If you half pack the Sorb cannister...how can it be actually PACKED? ....i imaging a 1/2 bag of rice or marbles

 

[mr_v]

@Baja Johnny - you're selling a rEvo in the Classifieds section, surely enough you know that you can under pack a sorb cassette because spring will put tension on the mesh cover. Moreover, rEvo's instructions call for about 5-7mm of space between the mesh cover and the top of the cassette when properly packed. Thus, in practice a properly packed rEvo sort cassette may be slightly under packed.