Cleaning and Inspection

TM 5-4220-226-14&P 4-21. Exhaust Valve Assembly Maintenance - continued. b. Cleaning and Inspection (1) Remove silicone sealer from valve body and from helmet shell with lacquer thinner. WARNING Residual lacquer thinner will contaminate the diver's air and can cause injury or death. (2) Remove all traces of lacquer thinner from components using NID solution and soft bristle brush. Wipe with clean, lint-free cloths. Rinse with fresh water; air or blow dry. (3) Inspect cover and valve body for cracks, bends, or other damage. Inspect exhaust valve for wear or deterioration. NOTE Do not re-use exhaust valve once it has been removed from the valve body. c. Installation (1) Apply silicone sealant around the edge of the sealing surface on the valve body (5). Insert valve body into helmet and fasten with three screws (4). Do not over tighten. (2) Wet new exhaust valve (3) with fresh water and install the valve in the valve body. Be sure the valve tip points toward the interior of the helmet. (3) Cut the valve tip so that it protrudes 1/4-inch from the valve body. (4) Place cover (2) over valve body and fasten with screws (1). 4-28