Water mist suppression system annual maintenance checklist

Monitoring company and owner notified before the mist test

Monitoring company told alarm and supervisory signals will come in, the owner notified, and the calls logged before any valve is operated or the system released.

Impairment opened and fire watch set for the protected area

Owner's impairment procedure followed for as long as the system is isolated or recharging, the protected area known to the owner, fire watch set where the procedure requires.

Occupants warned and the protected area cleared for discharge

People in and around the protected area told when the discharge will happen, the area cleared, and anything the water would damage covered or moved before release.

Pump unit serviced under lockout to the manufacturer's schedule

On a pump unit, every motor and control feed locked and tagged, oil, seals and coupling serviced to the manufacturer's schedule, guards on and locks removed by whoever hung them.

Nozzle strainers and supply filters serviced

With the section isolated and depressurized by the technician, nozzle strainers checked or cleaned as the instructions set, filter elements changed, and any fouling photographed.

Supply gauges compared with a calibrated test gauge

System and supply gauges compared by the technician with a calibrated test gauge, readings photographed, any gauge outside the manufacturer's tolerance replaced.

Supply water quality checked against the manufacturer's needs

Sample of the supply or fill water tested, or the latest test on file, against the manufacturer's water quality requirement, with any change in the water source noted.

Cylinder retest dates read on a cylinder-driven unit

Water and driver gas cylinder labels read, retest dates checked against the manufacturer's schedule and the governing cylinder rules, cylinders coming due listed.

Detection-to-discharge sequence witnessed

Technician seen initiating the sequence from detection and from the manual station, the release operating and the supply driving the nozzles, discharge time and supply pressures recorded against prior years.

Mist pattern at the nozzles observed

Mist seen reaching the nozzles over the protected hazard with the expected pattern, any blocked or misaimed nozzle flagged to the technician.

Ventilation shutdown and door release observed on operation

Where the design interlocks them, fans seen stopping, dampers closing and held doors releasing as the system operates, any interlock that fails written up.

Supply recharged and system dried after the test

Cylinders, accumulator or supply recharged to the manufacturer's mark after the discharge, piping and the protected area drained and cleaned before the system is reset.

System reset and supervision restored

System reset by the technician, section valves returned to normal and re-supervised, detection, release and controller supervision confirmed before the system is taken off test.

Monitoring company and owner told the mist system is back

Panel normal, the monitoring company confirming normal signals, the owner told, the impairment closed in the owner's log and any fire watch stood down.

Observed results and open items recorded on the building side

Observed discharge times, supply pressures and any nozzle or supply deficiency the technician calls out logged with a photo and a date on the site record, kept separate from the technician's certified report.