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Just a quick question about the first stage freeze up you mention below. Was the rubber cap designed to prevent freezing installed? CaptnDale@ao*.co* wrote: > > Certainly, a high flow first stage regulator has the potential for a greater > cooling effect. The reason we want high flow regulators is to have that flow > available during those stressful times when it just might be needed. Sure, > you could limit the potential for freezing by limiting flow but then you just > might not get the air you need in a tight situation. The key is to design a > regulator that is capable of high flow while incorporating design features > that protect against freeze-ups. > > Higher intermediate pressure causes a greater cooling effect in the second > stage, not the first. The cooling effect is due to the gas expansion. When > the intermediate pressure is higher, there is a correspondingly greater gas > expansion in the second stage. Poseidon regulators do, indeed, throw ice at > the diver, but that ice is produced in the second stage. With their upstream > design, ice forming in the airstreem would probably cause stoppage of the air > flow altogether. In fact, a buddy of mine had a poseidon second stage blow > right off of the end of his hose due to icing. This occurred at Lake Geneva > Wisconsin this last December on a day when the air temperature was somewhat > below freezing. Following his dive, he left his equipment laying on the > ground while he changed into warm clothes. When he went back to pick up his > gear he turned his air back on. There was a bang that sounded like a gunshot > and the regulator second stage shot off the end of the hose. It flew 30 feet > through the air. It had been attached to a 7 foot hose that was now whipping > around wildly. Another dive buddy was struck smartly with the hose and > stumbled into the lake. When we sorted everything out it became apparent what > had happened - The regulator first stage had frozen to freeflow and the second > stage had frozen closed. This caused the intermediate pressure in the hose to > rise to tank pressure, resulting in hose rupture. > -- Dave Mabry dmabry@mi*.co* Great Lakes Maritime Institute Underwater Research Team NACD #2093 NSS #42872 -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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