metal.
3.2.5
Cleaning Before Installation
Clean piping, components, and equipment before installation.
3.2.6
Cleaning Requirements
Clean surfaces containing no crevices or inaccessible areas by any of the
procedures described herein. Clean surfaces containing crevices by
immersion in unused or redistilled acetone, ethanol, or isopropanol only.
3.2.6.1
Vapor Degreasing
Vapor degreasing may be used on surfaces containing no crevices or
inaccessible areas and shall be accomplished by the following procedures:
a.
Dry all parts entering degreaser.
b.
Load parts onto racks in the condensing zone so that they do not
touch each other, and in such a manner to insure complete draining
of solvents.
c.
Use perchloroethylene bath. Maintain bath at 121 to 127 degrees C
250 to 260 degrees F. The bath shall contain a neutral inhibitor
to prevent acid formation due to hydrolysis. Other types of
inhibitors are not permitted.
d.
Change solvent when boiling point of perchloroethylene exceeds 127
degrees C 260 degrees F. Dump solvent earlier if cleanliness
standards are not attained.
e.
Lower or raise parts in the degreaser at a rate not to exceed 5
mm/s 12 inches per minute and immerse in vapor phase. Spray with
clean solvent during immersion time. Keep the spray nozzle at
least 305 mm one foot below the vapor line during spraying. Allow
part to remain in vapor until condensation ceases (3 to 5
minutes). Dry parts completely before removing from degreaser.
3.2.6.2
Degreasing by Immersion or Wiping
Degreasing of parts having no inaccessible areas or crevices may be
performed by immersion in solvent or by wiping with a clean lintless wiping
cloth saturated with the solvent perchloroethylene, unused or redistilled
acetone, ethanol, or isopropanol, or Stoddard solvent for preliminary
degreasing. Dry in accordance with paragraph entitled "Drying
Requirements."
3.2.6.3
Trisodium-Phosphate Detergent Cleaning (Degreasing)
Trisodium-phosphate detergent cleaning may be used on surfaces containing
no crevices or inaccessible areas and shall be accomplished as follows:
a.
Remove heavy dirt by either scrubbing with a non-shedding bristle
brush using a solution of up to 112.2 mL one fluid ounce of
nonionic detergent per liter gallon of tap water or immersing the
parts in a hot (approximately 71 - 88 degrees C 160 - 190 degrees F
) solution consisting of 207 to 296 mL 7 to 10 ounces of trisodium
phosphate and up to 112.2 mL one fluid ounce of the nonionic
SECTION 15212N
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