TM 9-4940-556-14&P
4.1.8.18 Install pressure tip or steam nozzle in unit, set MODE switch and
adjust air baffle appropriately.
4.1.8.19 Turn pump switch on, check coil inlet pressure gage with coil outlet
pressure gage, if pressure differential is more than specified in the instruc-
tion manual, the coil may need a second treatment.
4.1.8.20 Fill solution tank with correctly diluted cleaning compound.
4.1.8.21 Unit is now ready for normal operation.
4.1.8.22 If a second treatment fails to reduce the pressure differential
below the pressure specified in the instruction manual, the coil may need to
be removed and soaked in a solution of sulfamic acid.
4.1.8.23 Coil soaking is an alternative to avoid the high cost of requisi-
tioning a new coil. This can be performed by removing the coil from the
cleaner and soaking the coil in a sulfamic acid solution of five pounds of
sulfamic acid to five gallons of water. Enough solution should be mixed to
completely cover the coil in a suitable container. Check the coil solution
periodically for color. If the color of the solution is yellow, add two more
pounds of sulfamic acid to the coil solution. Repeat as necessary until the
solution stays a reddish color for at least 2 hours. This indicates very
little scale is present.
4.1.8.24 Before draining the solution from the coil container, it should be
checked and neutralized. Check the color of the solution, if the color is
yellow, the solution can be disposed of into a sanitary sewer with equal parts
of water. If the solution is red in color, add sodium hydroxide slowly until
the solution just begins to change from red to yellow. When this change
occurs, the solution may be flushed into a sanitary sewer with equal parts of
water. Rinse the coil with water for five minutes and pour the neutralized
solution down the drain, Reinstall the coil and test for leaks.
14.1