The objective is to flush the water system of the fire trainer in order to prevent the Legionella bacteria from developing in the un-used water lines.
Flame Aviation Instructor manual, paragraph 4.2
Flame Aviation Maintenance manual, paragraph 4.6 and 4.8
Fill two fire extinguishers in each automatic refilling station. It is not necessary to discharge the fire extinguishers. The fire extinguishers can be taken out of the bracket and after the green light switched off, the fire extinguishers can be replaced again.
Fill the coffee can in galley area and discharge the coffee can in sink. Repeat this job three times.