Orifice Selection in Semi-Closed Circuit Mixed Gas Underwater Breathing Apparatus

摘要

The report was prepared to support Man-in-the-Sea Operations wherein the gas flow requirements in semi-closed circuit breathing apparatus will vary over a wide range due to extension of diving depths in semi-closed circuit breathing apparatus to 600 feet of seawater. A graphical method of orifice selection is presented. Information for graph preparation was obtained through computer operations using standard compressible fluid flow formula for critical flow through an orifice. (Author)