(2)
Preventive maintenance.
(a) Clean sprayer daily after spraying. DO NOT allow formulations to
stand in the tank after use. Empty the sprayer and triple rinse the sprayer assembly
with clean water (one-tenth the volume of the sprayer per rinse is adequate). Remove
the pump cylinder assembly, nozzle, and screen, and depress the shutoff assembly
using a rubber band. Hang the tank upside down to dry and lubricate pump cylinder
assembly with lightweight oil. Be careful when using wrenches on fittings and when
reassembling the sprayer. Most threaded connections have tapered threads; others
have gaskets between fittings. Tighten the connection only enough to prevent leaks.
Extra tightening will only weaken brass threads and shorten the sprayer's service life.
(b) If the nozzle tip clogs during sprayer, do not attempt to force it open
with pressure. Release pressure from tank. Remove and clean shutoff strainer and
nozzle strainer, and clean nozzle tip. Do not use wire or blow with your mouth when
removing and reassembling shutoff strainer. Do not use pliers on the housing for this
strainer; it is removable by hand.
(c) To maintain pumping efficiency and ease of operation, add a few
drops of clean, light lubricating oil through the small hole in the pump cap. Also, add a
few drops through the plunger tube hole in the pumping cap to lubricate the plunger
tube. Should the leather cup dry-out, the pumping stroke will be ineffective. Remove
the plunger from the pump cylinder and work oil into the leather with the fingers until it is
supple. DO NOT use grease for this purpose.
(d) If the discharge rate from the nozzle tip is irregular, excessive air is
probably entering the discharge line. Check the tightness of the hose connector where
it is attached to the tank. If this fitting is properly assembled, check the supply tube
gasket and replace if necessary.
(e) If the air pressure head within the tank seems to decrease rapidly,
check the tightness of the pump cap on the collar of the tank top. If this fitting is
properly assembled, check the pump cylinder gasket for defects and replace if
necessary.
(f) Occasionally the pump cylinder button valve may become worn or
misformed to the point of allowing liquid to enter the pump cylinder. Carefully remove
the valve from the cylinder for inspection and, if necessary, replace it by snapping a new
valve into place.
c. Duster, Manually Operated, Tubular Pump, NSN 3740-00-132-5936. This
hand duster (see figure 3-8) is made of galvanized tin or plastic and holds about one
pound of dust. It is suitable for spot treatment of fleas, ants, and insects in ornamental
shrubbery. It may also be used for delousing troops or civilian populations. The
MD0171
3-9