Kirby Morgan 77
3.8.6 Testing the Breathing System
Test the defogger system by turning on and off the defogger control knob. There should be no leakage when the valve is closed. The regulator should be adjusted by turning the adjustment knob out until a slight steady flow starts, then back in until the flow just stops.
Next, the demand regulator system is checked for proper function: breathe in and out. Inhalation and exhalation effort should be nearly unnoticeable. Press in on the regulator cover. This should produce a strong burst of breathing gas.
Test the breathing system to make sure that it is op- erating correctly.
3.8.7 Sealing Integrity Check
If there is any doubt that the helmet is sealing prop- erly, perform the following test prior to diving.
Turn the supply gas off at the dive control system and bleed the umbilical.
To perform this test, the diver must have an assistant standing by. The assistant should be in control of the gas supply console in the event the diver needs air or he must be ready to lend a hand. The diver must be next to the dive control manifold so that the air may be turned on instantly, or the diver must be ready to run a hand between his neck and the sealing neck dam in order to pull the neck dam away from the neck to allow breathing.
With the neck dam ring on the diver’s head, the helmet
is installed and the locking collar closed. When the diver attempts to inhale, a suction on the neck dam is formed, indicating he is achieving a good seal. The diver must then turn the air on immediately so that he can breathe. If the diver does not turn the air on he will not be able to breathe, unless the neck dam is pulled away from his neck.
WARNING
Do not perform this test unless the diver and his tender are stationed immediately adjacent to the diver’s air manifold and you are certain the air is on to the mani- fold. If the diver is unable to flow air to the helmet, either through the umbilical or the bailout, he may not be able to remove the helmet easily.
To break the seal in this situation, the diver must put his hand between the neck dam and the neck, and pull the neck dam away from the neck. A tender must be standing by to assist the diver in removing the helmet if needed. Suffocation could result.
3.8.8Adjust Regulator for Low Work Rates
At very low work rates, such as when the diver is resting, or during
In order to ensure that carbon dioxide does not accu- mulate in the mask, divers who are at rest underwater should screw the regulator adjustment knob “out,” i.e., away from the regulator, until a slight steady flow occurs and the regulator can be heard to hiss. This will help to eliminate any excess carbon dioxide from the mask. You can also open the steady flow valve (defogger) until a slight hiss is heard.
WARNING
Excess carbon dioxide (CO2) is danger- ous. Too much carbon dioxide in the diver’s breathing system can cause the diver to feel that he cannot breathe for comfort. It can also cause headache, confusion and rapid breathing. In extreme circumstances, carbon dioxide can cause unconsciousness. This could lead to suf- focation and death.
© Copyright | 57 |
