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David Drake asked that I post further iformation concerning my attempt at pumping Trimix from some single 120's to a set of duals using my Rix SA-6 and the problems encountered. He also noted that my signature didn't have my E-mail address (I wondered why I hadn't gotten an occassional private "love notes" or two from the list! Actually had grown kinda fond of the private ones!). Anyway, the signature problem is resolved and the E-Mail addresses added. On to the real issue at hand: I had filled two single 120 cu.ft. tanks with Trimix 46/16 in the past so as to allow some friends to do a short dive to 240fsw to see a wreck known as the Triple Crown when we had a bouy on the wreck. One of the friends asked me just a few questions, but it was enough to make me realize just how stupid it was to even consider taking them down on Trimix without the Advanced training (no flames please, I know it was dumb, dumb and dummer) so the tanks just sat there using space, gas not being used and my two Nitrox and O2 cleaned single 120's were essentially useless to me. Rather than just dumping the gas I wanted to transfer it one sets of my duals. Figured it shouldn't be a problem using the RIX SA-6. The Rix folks advised against doing this especially if the inlet pressure was at all positive as the machine isn't designed, they say, for a positive pressure on the inlet side. OK, the solution, we thought, would be to hook up a good breathing scuba regulator to the inlet hose and let her rip. Gave it a try using the 6' piece of inlet hose as the only reservoir. We found that due to the dynamics of the compressor, the regulator daiphram dynamics could not respond to the intake pulses of the compressor well and so the result was that there was alot of wasted gas out the exhaust ports of the regulator at the end of each intake stroke. A second attempt was made using a sensitive vacumn/pressure guage and manually feeding the intake tube as close as possible to normal ATA. While this met with better succuess and less gas waste, problems were still encourtered due to the resident volume of the compressor and extra dryers and filters attached thereto. Also manual regualtion was very diffult and if ever tried again would require better controls such as flow meters etc. used in welding gear and perhaps the use of another large reservoir on the intake side to dampen the pulses. End result, in my opinion, is waste of time as compared to cost of gases saved. Would never try it again unless, perhaps someone gave me 100's of used He tanks with psi levels of 500 or so and some bottles to bank the He at high pressure. Real answer is what's designed for the use: A Haskell booster pump. Still, it hurts to throw out gas from an aborted dive etc. and start from fresh, but without the proper equipment it's too difficult in my experience and the "remixed brew" may be questionable without an He analyzer. Just an O2 analyzer isn't enough to verify under these circumstances in my view. Off the soap box and back to diving after L4-5 disc surgery! Harold H. Gartner III 6900 Via Alba Camarillo, California 93012 home: (805) 482-9743 home fax: (805) 987-6804 office: (213) 487-6240 E-Mail: hgartner@ra*.or* CompuServe 71470,1423
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