6-50. What is the purpose of the low- pressure switch in an aircraft’s oxygen supply line? 1. To operate the oxygen caution light 2. To cut off oxygen servicing when the aircraft system is full 3. To warn personnel servicing the aircraft that the system is approaching full 4. To complete the electrical circuit to the LOX quantity indicator 6-51. How does a crew member know when the LOX( system is in a low state? 1. By dchecking the quantity indicator 2. By the illumination of a low quantity light 3. By both 1 and 2 above 4. By checking the oxygen pressure gauge 6-52. What is incorporated in the LOX system to protect the pressure regulator and crew member from excessive pressure should the LOX converter malfunction? 1. A thermal expansion valve located between the LOX converter and the oxygen regulator 2. A thermal expansion valve located in the LOX converter 3. A relief valve located in the LOX converter 4. A relief valve located in the oxygen shutoff valve IN ITEMS 6-54 THROUGH 6-58, SELECT FROM COLUMN B THE ACTION THAT RESULTS FROM THE MINIATURE OXYGEN BREATHING REGULATOR FUNCTIONS LISTED IN COLUMN A. ACTIONS IN COLUMN B MAY BE USED MORE THAN ONCE. 6-54. 6–55. 6-56. 6-57. 6-58. A. Functions. Oxygen flow from the paddle base area produces a pressure drop behind the demand valve diaphragm The sensing diaphragm returns to the balanced position The small volume bleed vent closes the aneroid vent B. Action 1. Oxygen flow 2. Safety pressure obtained 3. Automatic pressure breathing 4. Opens the mask exhalation valve and builds up pressure on the sensing diaphragm The sensing diaphragm force is equal to the aneroid chamber force The relief valve acts as a pivot device 6-59. Which of the following are low pressure oxygen regulators? 1. Miniature and MD-2 2. Miniature and MD-1 3. MD-1 and MD-2 4. Miniature only 6-53. Which of the following types of tubing is used in LOX systems aboard aircraft? 1. Low-pressure aluminum alloy 2. High-pressure aluminum alloy 3. Low-pressure stainless steel 4. High-pressure stainless steel 43