Kirby Morgan 77
from inverting the helmet exhaust valve when hitting the water.
The diver must report to the surface immediately after the entry. It is a good policy to descend 10 or
20FSW
The purpose of this adjustment knob is to allow the diver the ability to compensate for variations in um- bilical supply pressure. This adjustment device oper- ates by simply increasing or decreasing the amount of spring bias tension on the demand regulator inlet valve.
This adjustment device is not intended as a minimum- maximum device. Minimum and maximum applies to supply pressure only. The adjustment knob should be adjusted by the diver to be at the easiest breathing setting at all times.
Diving a KMDSI helmet or band mask with a bias setting greater than that just necessary to keep the demand valve from free flowing increases the work of breathing and reduces the diver’s ability to perform heavy work.
Then the diver checks in with the surface before descending to the job. If a closed bell is being used, the diver enters the water from the bell and pauses for a short time outside the trunk until he is sure all systems are operating properly.
During the decent the communications must be checked again and the diver supply pressure should be adjusted as necessary to maintain the required
3.11 Emergency Procedures
3.11.1 Flooding
In the event of partial or complete flooding, the diver may clear the helmet quickly by tilting the helmet forward and slightly down and activating the defogger control knob. Pressing in on the manual purge but- ton in the center of the regulator cover will dewater the regulator.
After clearing, cautiously check for additional flood- ing. If the helmet continues to take on water, return to the diving station, swimming with the water dump valve positioned at the lowest part of the hat: that is with the diver’s face forward and slightly tilted down. Keep the free flow knob on. This increases the air/gas pressure slightly inside the hat and keeps the water out. Any incoming water is automatically purged.
3.11.2 Inhalation Resistance
If breathing becomes difficult, adjust the demand regulator adjustment knob, for easier breathing by rotating the adjustment knob counter clockwise. If the breathing does not get noticeably better, press the purge button in the regulator cover. If a surge of gas does not flow with this action, open the emergency valve.
If the flow is noticeably better, immediately notify topside that you are on emergency gas. Insure your umbilical is clear and return to the stage or decent line. The diver should stay in communication with topside personnel and make preparations to abort the dive. The console operator should check to ensure the sup- ply pressure to the diver is at the proper pressure.
3.11.3 Gas Flow Stops
A stop of flow in the demand regulator usually in- dicates the main gas supply has stopped. The diver should first open the emergency valve by turning the knob. If there is still no flow from the demand regulator, the defogger valve knob should be opened. Keep in mind that if the defogger valve is left open, the bailout bottle will drain very quickly, particularly if the diver is deep.
Immediately notify topside, check to insure your umbilical is clear and return to the diving station us- ing the emergency breathing supply. Avoid making a rapid ascent if at all possible.
Once at the surface, or inside the bell, the diver may remove the helmet if needed. Never ditch the hel- met underwater unless conditions absolutely require that.
60 | © Copyright |