[PSUBS-MAILIST] Co2 scrubbers on eBay

[Private via Personal_Submersibles]

Rick,

While we're on the subject, here's a few more details that might be worth mentioning.

The through-hull for O2 shouldn't be just a nipple welded into the hull, because you'll need to remove it for cleaning. Kittredge had a nice design.  Mine consists of a bored SS insert welded into the hull. A removable through-hull made from a large SS bolt fits into that insert and is secured from inside with a nut.  The bolt head is on the outside acting as a shoulder and seals against the welded insert with an O ring. I bored the bolt and put NPT threads on each end, so the O2 has no contact with the O ring, which can be "dirty."

The hull stop needs to be a slow-acting valve such as a needle valve. No ball valves for O2, they are too violent. Mine are basically like the valves on a SCUBA tank, and came O2 clean from the manufacturer.

Clean all lines and connections per Oxygen Hackers Handbook instructions.

The medical regulator should be pediatric, as that gives you smaller graduations.

Avoid a flow regulator that has the CGA 870 connector like the plague. These are the ones with two little studs, and they use a rubberized disc instead of an O ring. They are evil, I think they designed those seals to maximize leaks. Instead get a flow regulator with a CGA 540 connection. NPT to CGA 540 adapters are readily available, probably at your local welding store.

Best,

Alec

> On Apr 26, 2017, at 7:14 AM, Brian Hughes via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
> Mark,
> 
> Here's how I plan to try it:
> 
> 1) Ordered an XS Scuba tank holder from Amazon - the bungee one for holding scuba tanks on a boat
> 2) Ordered the fan Alec recommended as it's the same one I use on my current setup and worked well for him.
> 3) Printed out the fan emergency hose adapter. Send me an email and I can send back the stl files I got from Alec. Brian at stjohnmd.org
> 4) Bought an MSA M COMFO respirator hose setup on eBay. They are cheap.  It can attach to the adapter mentioned above and turn the canister into a huge lung powered scrubber without having to hold the hose bit it in your mouth with a scuba regulator mouthpiece. It will scrub inhalation and vent exhalation back into the sub, but a zero net gain.
> 5) Months ago I scored a box of medical clamps used for attaching things to those roll around poles in the hospital. They're perfect for temporarily or permamently attaching things to Harold's reinforcing rings. I can switch between which size canister setup I want to use.
> OK, here's what will get tried and I'll post pics when done.  In no particular order.
> 
> Tank holder gets connected to medical clamp with a spacer if needed to hold out scrubber from the radius of the interior. Canister will be attached to side of the rear most starboard reinforcing ring, vertically in the middle. Drill and tap top of canister for attaching fan, make an o-ring for a proper seal.  Fan hose adapter glued to the fan.  Weld a small piece of angle iron to the reinforcing ring to hold the bottom edge of the canister.  Clamp on with fan pointed forward.  Wired with 20 amp anderson plug that, with a Y adapter, is already there and used for the ice chest based AC system (google redneck AC for images).
> 
> Not an engineer and likely Alec shakes his head every time he sees one of my sub hacks, but it keeps me home at night. :-)
> 
> 
> 
> 
> 
> 
> 
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