Evaluation of the U.S. Divers Nordic Scuba Regulator for Use in Cold Water
Technical rept. Jan 1995-Jun 1996
NAVY EXPERIMENTAL DIVING UNIT PANAMA CITY FL
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NEDU tested the breathing effort and susceptibility to freeze-up of the U.S. Divers Nordic SCUBA regulator. Five regulators were tested in 28 deg F -2 deg C salt water, at depths to 198 fsw 60.7 msw. The probability of regulator failure was computed from the number of cold induced incidents, and the time to failure for each incident. There were no freeze-ups of the first or second stages. However, resistive effort was remarkably high, especially at low bottle pressures. The first stage regulator frequently malfunctioned due to the loss of silicon oil. High breathing pressure events during the resistive effort measurements occurred at mass flow rates exceeding 300 gmin at a 1500 psi supply pressure. Due to leakage of silicone oil and high breathing effort at low bottle pressures, the U.S. Divers Nordic is not recommended for Navy use in cold water 28 deg F at any depth.
- Life Support Systems