If visible contaminants

If visible contaminants are evident through visual inspection, those portions of
the system where contaminants are visible shall be re-cleaned and subjected to
re-inspection for cleanliness.
3. NADCA vacuum test analysis should be performed by a qualified third party
experienced in testing of this nature.
(C) Verification of Coil Cleaning
1. Cleaning must restore the coil pressure drop to within 10 percent of the pressure
drop measured when the coil was first installed. If the original pressure drop is
not known, the coil will be considered clean only if the coil is free of foreign matter
and chemical