NAUI Master Diver Scuba Final Exam Questions With Verified Answers

NAUI Master Diver Scuba Final Exam Questions With Verified Answers DIVE EQUIPMENT Open-circuit demand scuba is most commonly used by recreationals divers, closed-circuit and semi-closed rebreathers now available - answerTrue DO NOT GET MOISTURE INTO THE CYLINDER. Water will cause corrosion by combining with high pressure oxygen inside the cylinder. - answerTrue ^^ Prolonged storage of air in a steel cylinder containing water can be bad. Oxidation process will consum some of the oxygen in the air, leaving higher nitrogen concentration - answerTrue Always keep 300 psi of pressurized air in cylinder to prevent moisture accum. Bad if slosh heard, whitish mist or odor. IF COROSSION IN CYLINDER THIS CAN BE CLEANED BY TUMBLING - so fill it with aluminum oxide chips or abrasive materials and rotate for many hours removing rust - answerTrue Hydrostatic filled to 5000 psi or five thirds of the rated pressure of the cylinder, fill 300-500 psi per minute - answerTrue Standard on-off cylinder in usa is k-valve, low air warning mech. is j-valve (two sides). This valve lever should be fully up to reserve air if they forget or if diving eliminates that can be turned down but air will release quick without warning - answerTrue dual valves like Y-valves or H-valves allow diver to mount two regulator systems on single cylinder for deep or enclosed dives - answerTrue First stage in regulators reduces cylinder pressure to intermediate or low pressure around 90-150 psi - answerTrue Upstream valves rare, downstream more resistant to operate as cylinder prerssure decreases b/c failure in closed position. Third valve is balanced valve - answerTrue First stage includes diaphragm and piston. - answerTrue Intermediate pressure remains at a constant above ambient pressure as diver descends or acends - answerTrue