-10- 



(2) Check the breathing apparatus. Does it deliver air 

 to the mask? Is the tank full of air? The two individuals 

 using the equipment should put on the breathing equipment in 

 normal air and use up a tank of air while doing routine tasks, 

 They can then become accustomed to the apparatus, learn some- 

 thing about its limitations and hear the alarm when the air 

 level in the tank is nearly exhausted. The tanks should then 

 be refilled prior to use in the CA storage. 



(3) Review the symptoms of asphyxia so you won't take 

 any chances . 



(4) Remove the window in the gastight door of the CA 

 storage room. 



(5) The repair person enters the CA room with breathing 

 apparatus. The back-up person must keep the repair person in 

 sight. If this can be achieved from outside the CA room, the 

 back-up person should be ready to enter the CA room, but not 

 use the air until necessary. The back-up person may need to 

 enter the CA room to keep the repair person in sight. If 

 both people are in the CA room and one person's warning bell 

 rings to signal the tank is almost empty, then both people 

 should exit the CA room. If one must climb the ladder, the 

 second should stay on the floor. If both need to climb the 

 ladder to maintain visual communication, drag-rescue cannot 

 be accomplished. Open the room and vent with air. 



(6) If you vent the CA room with air and then need to 

 restore the CA atmosphere, but do not have access to an 

 oxygen burner, you can flush out the oxygen with nitrogen 

 gas. Order the nitrogen gas in the liquid form (large thermos 

 bottles), in trailer truck cylinders, or in regular cylinders 

 with a manifold. A tightly packed room will require about 2 

 cubic feet and a room with plenty of free air space will 

 require about 3 cubic feet of nitrogen gas per bushel to 

 lower the oxygen concentration from 21% to 5%. Use a garden 

 hose to deliver the nitrogen gas to the intake of the blower 

 in the CA room. Leave the porthole open to relieve pressure 

 in the room. 



* 



The description of asphyxia was taken from Noxious Gases and 

 the Principles of Respiration Influencing Their Action by Yandell 

 Henterson § Howard W. Haggard. Reinhold Publishing Corp . , 330 

 West 42nd Street, New York, N.Y. 



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