Larger amounts of CO2 or nitrogen gas must be used to purge large fuel cells or multiple fuel
cells with one filler neck.
After purging of the fuel cell has been completed, wait approximately two to three hours, and test fuel cell for
the presence of dangerous fuel vapors with a combustible gas exists, use additional purging gas until a satisfactory test is
Preserve fuel cell by coating all interior surfaces with lubricating oil, MIL-L-6081, grade 1010.
Attach a tag to the fuel filler cap with the following information printed on it: This fuel cell has been preserved
with lubricating oil, MIL-L-6081, grade 1010. No flushing required during depreservation.
Preservation. General preservation procedures for storage or shipment of fuel cells are explained in the
following paragraphs. Special instructions for Goodyear Nylon (PLIOCEL) fuel cells are also explained.
Extreme care must be taken in the cleaning of fuel cells to prevent abrasion or other injury, or
the cell may be permanently damaged.
General fuel cell cleaning. Remove all foreign material from the exterior of the cell with a clean, soft
cloth or a soft fiber brush. If additional cleaning is necessary, wash exterior of cell with a soap paste, P-S-560, and water
at a maximum temperature of 180 °F (82.2°C). After cleaning, remove all soap residue with clean hot water and dry
thoroughly. Interior sediments or other contaminants should be wiped out with a dry, clean, soft cloth and/or flushed out
with lubricating oil, MIL-L-15016, MIL-L-6081, or VV-L-825. Drain excess oil, if applicable.
PLIOCEL cleaning. Remove all foreign material from the exterior of the cell with clean, dry, soft
cloth or a soft fiber brush. If additional cleaning is necessary, clean with a soft cloth moistened with methylethylketone,
TT-M-261. Care should be taken to remove all of the chemigum coating on the exterior of the cell. Interior sediments or
other contaminants should be wiped out with a dry, clean soft cloth and/or flushed with a solution of equal parts of water
and glycerine. Drain the excess glycerine solution, if applicable.
Drycleaning solvent is flammable and solvent vapors are toxic. Use P-D-680 Type II Solvent in
a well-ventilated area. Keep away from open flames. Avoid prolonged solvent contact with
· All steam lines used to clean tanks must be properly grounded at discharge end of line to
prevent possibility of static discharge.
· Do not allow live steam to jet directly onto metal of tank. Use diffuser plate or keep steam
jet at least 20 inches from tank surfaces.
Metal tank cleaning. When necessary, clean tank exterior using drycleaning solvent, P-D- 680, Type
II. Thoroughly flush tank interior with hot water admitted at bottom of tank. Allow to overflow at top. After flushing with
water, mount tank into position with one opening at top of tank and one opening at lowest point at bottom of tank. Close
all other openings. Clean tank for a minimum of 3 hours with live steam. Do not use steam vapors in lieu of live steam
General fuel cell preservation. If the interior of the fuel cell was not completely coated with
lubrication oil during the cleaning process, coat the interior of the fuel cell with one of the lubricating oils referenced in
paragraph (a). This coating may be applied by painting, spraying, fogging, or sloshing. Drain excess oil prior to storage
or shipment. Preserve all metal fittings with corrosion preventive compound, MIL-C-16173, grade 2.
Make certain that the corrosion preservative compound does not come in contact with the
rubber portion of the fuel cells. The rubber may become deteriorated and decrease the
integrity of the tank.