TM 5-1940-321-13&P
NOTE:
Correct Pressures are: Buoyancy Tubes 240-280 mb (3.5 4.1 psi) Keel
220-240 mb (3.2 - 3.5 psi).
a. Buoyancy Tube Pressure Check. Check buoyancy tube pressure as follows:
( 1 ) Obtain pressure gauge, foot pump, and hose from stowage pouches near bow.
( 2 ) Remove isolator clamps from the inflation hoses connecting the upper
buoyancy tubes to lower Buoyancy tubes (located aft of the transom).
( 3 ) Turn all four intercommunicating valve flywheels so that the indicating arrow
points to the 12 o clock position (orange area marked INFLATION).
( 4 ) Remove the metal valve cap from one of the four intercommunicating valves
and insert the pressure gauge firmly into the valve.
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