Loop flow

caveseeker7

I pretty much guessed what Dave said.
The 'rich is right, lean is left' gas setup is pretty much the standard for diving.
A second 'standard', as Dave pointed out, is to inject O2 on the exhalation side and diluent on the inhalation side. (Never mind the Inspo's solenoid injection point ).
There are only two ways to achieve this and stick with a third convention, to have separate sides for each gas arrangement, is either run a clockwise loop or to inject all gas in a central area like the center section (MK series) or head (Shadow Pack).

SMI choose to break with the rich/right - lean/left convention by placing the O2 on the left, sticking to separate sides and injection points.

ISC decided to break with the (manual) injection point and stick with separate sides, the right one being rich.

From what I gather a few Meg divers decided to break with sides, crossing hoses and keeping with the manual injection points.

Personally, I think the MK series/Shadow Pack solution is better than any of those three.

With the CCR1000 being the first production CCR and adopted by the military, the counterclockwise gas flow became the standard. Especially for the military as they like to keep things simple.

Hence my guess is that units based on military designs have counterclockwise gas flow like the the Azimuth (civillian version of the RDN2000), designed by people with military background (Leon's Megalodon) or designed with military use in mind (PRISM and Shadow Pack).

Why in the world Dräger routed the gas clockwise in the Dolphin (based on the military LEBA something or other) and counterclockwise on the civilian Ray is beyond me. Their SMS2000 CCR prototype also had a clockwise direction.

Add-ited: This is one of those areas where I really whish there was a standard followed by everyone. It is less of a problem when one dives a single unit with divers on the same rig. But with different CCRs, in a group, multiple units or when switching, there is unnecessary potential for an accident.

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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.!"

dave t

Yes well spotted but in my defence the solenoid does inject before the sensors not after!!


As for the edit bit, couldnt agree more!!

best

Dave

Beanie

hey mines on the right (just )
now for the argument as to which way round we should all go

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dave t

Oh thats easy clockwise of course

seriously the rich is right ethic was/is a good safety rule for OC tech diving so why not for Rebreather's its a rule thats been around for a while, it means all team divers (non DIR of course) are rigged the same and I think that was caveseekers point!!

caveseeker7

Sorry Dave, didn't mean to give the wrong impression about the Inspo's solenoid injection, other than being after the scrubber being unconventional. As it's the automated gas addition it doesn't matter in regards to manual operation that we have drifted to (apology to DC too ... I hope your question was answered )

You must be one of those Inspiration people.

Very much so. It's a good rule and easy to remember. Maybe these days with more people switching to CCRs before they get into multiple gas diving (or at least accustomed to them) it may not be quite as important as it used to be.

Nevertheless I would like to see it as a standard for the above reasons, and to lower chances of user (or buddy, in an emergency) error.

The DIR chaps are rigged the same as one another, just not like normal divers.
Probably because they're wired lke one another, just not like normal divers.

__________________
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.!"