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Post by Dennis on May 11, 2003 18:43:17 GMT -8
On a double hose regulator, why do they use a duckbill valve at the top of the exhaust hose instead of a flapper valve (like at the left side of the mouth piece)?
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Post by Terry on May 11, 2003 18:48:11 GMT -8
Dennis; the reason that the duckbill valve is used for the exhaust purposes depends on the regulator. Some regs use the duckbill valve, and others such as The Nemrod Snark III use the one-way exhaust valve that you also mentioned which is in the mouthpiece. Hope this answers your question. Terry Stevens |
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Post by Tom Madere on May 30, 2003 13:25:11 GMT -8
Originally the old U.S. Divers two hose regulators did not have ths flapper valves in the mouth peice only the flutter valve (duckbill) at the end of the exhaust hose. If you were to have the mouth peice come out of your mouth the intake hose and the 2nd stage chamber could become flooded and the only way to get air going again was to drink all the water in the hose and 2nd stage chamber or use both hands in a motion like milking a cow to pump the water out. Either of which is difficult to do. The flapper valves keep the hoses dry. If there was no flutter valve on the end of the exhaust hose it would fill with water between exhalations and have to be forced out like clearing a snorkel.
Tom Madere
Diver since 1957
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