TM 5-1940-321-13&P
( 6 ) Remove the large neoprene valve base gasket from the threaded section of the
valve base folding it to pull it through the hole in the fabric. Do not remove the
plastic sheet underneath the neoprene gasket. This plastic protects the fabric from
the very cold CO2 gas during automatic inflation. Make sure there are no puckers in
the plastic which could result in air leaks.
( 7 ) Install a new large neoprene valve base gasket by folding it to pass it through the
hole In the fabric. Verify that the gasket is pressed down completely flat on the
valve base flange and pull the valve base through the hole in the craft s fabric.
( 8 ) Reinstall the grooved metal compression washer and the base nut. Tighten it using
the collar nut spanner. Tighten it moderately. Avoid tightening the valve base nut to
the extent the valve base flange inside the buoyancy tube turns.
( 9 ) Reinstall the CO2 hose coupling using a new neoprene gasket, if the existing
gasket appears worn or damaged.
( 10 ) Reinstall the small neoprene o-ring in the throat of the CO2 coupling and then
install the slotted nylon plug. Inflate the craft to 240 mbar (3.5 psi).
( 11 ) Using the collar nut spanner, check the tightness of the valve base nut. Tighten
moderately, but firmly. Do not apply excessive force. Do not tighten to the extent
that the valve base inside the buoyancy tube rotates.
i. Remove and Replace the CO2 Inlet Valve Base. This corrective maintenance procedure is
performed by direct support personnel. Removal and replacement of the CO2 inlet valve is only performed
when the valve threads are damaged or other conditions exist which cannot be repaired. Before removing
and replacing the CO2 inlet valve, verify that the problem cannot be corrected by servicing the valve while
it is installed in the buoyancy tube. Refer to figure 7-22 and the following paragraphs for serving the CO2
inlet valve:
Replacing Inner Neoprene Gasket, paragraph 7-18h.
7-33
