Table 2-2. Predive Setup Procedures

TM 5-4220-226-14&P 2-6. Predive Setup Procedures - continued. Table 2-2. Predive Setup Procedures - CONT Step Procedure 2. Connect and check emergency e. Check that no air is escaping through the one-way valve by air supply - continued holding a moistened finger lightly to the main air supply inlet. WARNING It is required that the emergency air supply be worn on all dives to depths in excess of 60 feet. It is recommended that it be worn on shallow dives (less than 60 feet deep) as well. f. Close the cylinder valve and the emergency air supply valve on the side block. Wipe any residual moisture from the one-way valve. 3. Connect and check main air WARNING supply. Never connect the main air supply hose (umbilical) to the emergency air supply inlet. The emergency air supply valve does not incorporate a one-way valve to protect the diver from baratrauma (squeeze) in the event of loss of pressure in the umbilical. a. Using the helmet adapter hose, connect the umbilical to the main air inlet on the side block assembly. NOTE Use two wrenches to connect the umbilical - one to hold the adapter and one to turn the hose fitting to prevent damage to the adapter threads. Umbilical connection should be snug but not overtight. Do not use excessive force or the adapter will be damaged. b. Turn on the main air supply from the surface support platform. c. Slowly open the steady flow valve on the side block and check for flow of air into the helmet. d. Close the steady flow valve. e. Momentarily depress the demand regulator purge button. f. Turn dial-a-breath knob out until regulator freeflows, then turn knob back in until it stops. g. Extend the nose block device outside the mask. 2-6