4-31. Clean Area.
All cleaning for life support air systems to be performed on components and piping shall be cleaned in a "clean
area." This area shall be isolated from oil, grease, paper, lint particles, and other airborne contaminates. It
shall be as free as possible of dust and debris. Workbenches shall be covered with easily cleaned surfaces
such as stainless steel, synthetic rubber, vinyl, linoleum or formica. Floor shall be non-dusting. Walls and
ceiling shall be covered with washable vinyl, latex paint, or polyurethane-based paint.
4-32. Removing and Installing System Components or Piping.
a. General. The following steps are guidelines for the removal and installation of piping or components
from or into a clean system. In general, common sense and clean work habits must prevail at all times to
maintain system cleanliness. Prior to the removal of any pipe or component, appropriate maintenance forms
are to be completed and approved.
b. Removal. Extreme care shall be used in the removal of any component or pipe from a clean system
to avoid introducing any contamination. To eliminate any chance of contamination, the following steps shall be
(1) Secure the system by closing valves and controls both upstream and downstream of the component
or pipe to be removed. The components shall be tagged to ensure that gas is not brought on line.
(2) Removal of all debris, such as dirt, dust, loose paint, and grease from the intended area of assembly
or disassembly is mandatory. This includes cleaning the pipe or component which is to be removed
and the adjacent components or piping.
(3) Wipe all external surfaces of components and piping with detergent to remove grease or dirt.
(4) All personnel shall have clean hands.
(5) All tools used in the removal must be clean and grease-free.
(6) Remove component or piping.
(7) Immediately bag or seal all exposed ends of system with plastic.
c. Installation or Reinstallation.
(1) The new component or cleaned pipe shall be wrapped or double-bagged. If not, the item shall be
returned for cleaning.
(2) The component or piping shall be removed from bagging and shall be inspected for damage at the
mating surfaces, threads, or connecting surfaces and any primary surface. Inspect for dust or minor
particle contamination, and remove with lint-free rag.
(3) Mating components and pipe shall have protection materials or plugs removed.
(4) Mating surfaces, preformed packings, and threads shall be coated lightly with an approved lubricant.
Threaded surfaces must be coated to prevent galling of threads at assembly.