TM 9-4940-556-14&P
4.1.8.11 With the pump switch "ON" and the burner switch"OFF", allow the
water to start recirculating through the cleaning gun and into the water
reservoir.
4.1.8.11.1
"WARNING"
Do not allow the unit to produce steam with the cleaning solution circulating
as injury to personnel may result from fumes or hot acid splash.
4.1.8.12 Pour approximately two pounds of sulfamic acid into the water reser-
voir tank. Turn on the water pump to circulate the solution. After thirty
minutes, turn off the water pump and check the color of the solution. If a
yellow color is present, the sulfamic acid is spent. If scale is still present
in the heating coil, repeat the above adding 2 pounds of sulfamic acid at 30
minute intervals until the solution remains a reddish color for thirty minutes.
During the above procedure cycle the burner (turn on and off) just long enough
for the cleaning gun to feel warm but not hot. It may be necessary to stop
cleaner from time to time to remove scale accumulation from dished filter
screen and/or to pump excess solution into another container to avoid over-
flowing water supply tank. This excess solution must be subsequently neutral-
ized using sodium hydroxide mixture outlined below. Turn off the water circu-
lating system.
4.1.8.12.1 NOTE: Carbon dioxide is released as long as scale and sulfamic
acid are present. After the scale is dissolved, gases cease to form and the
color of the solution remains a reddish color.
4.1.8.13 Before draining the solution from the steam cleaner, it should be
checked and neutralized as necessary. If a yellow color is present, the
solution is spent and can be flushed into a sanitary sewer with equal parts of
water, If the solution is a reddish color, it should be neutralized by adding
Sodium Hydroxide (NSN 6310-00-270-8177, 13 oz). Turn on the water pump and
slowly add enough sodium hydroxide to just change the color of the solution to
a yellow color. When the solution just changes from red to yellow, it can be
disposed of as outlined above.
4.1.8.14 STOP UNIT. Remove end of cleaning gun from float tank and place
discharge end of gun in a drain or other location for disposal of solution.
4.1.8.15 Turn ON water to unit. Start unit
and
open
nozzle
control
to flush water thru unit for ten minutes.
4.1.8.15.1 Flush with water any areas of unit splashed with acid.
4.1.8.16 Remove tips/nozzle from float tank.
4.1.8.17 Remove hose from coil outlet to allow sediment collected to flush
out. Re-install hose.
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