Fire service installations and equipment engineering
Domain 6 tests the engineering of fixed installations: water supplies, pumps, risers, hydrants, hose reels, smoke control and emergency lighting, and how each is proven at commissioning.
Water supplies and pumps
The design case is the worst credible simultaneous demand, typically sprinklers plus hydrants/hose reels plus any drencher, not the sum of every system at full flow. Pumps are duty/standby with automatic changeover, a jockey pump holding pressure, and pressure switches set so the main pump starts on a genuine pressure drop rather than on jockey cycling. Suction arrangements must avoid vortexing and air entrainment. Tank capacity is pump duty × duration plus any non-fire allowance.
Risers, hydrants and hose reels
The FSI Code sets thresholds by building height and volume that determine whether a dry riser, wet riser or sprinkler-fed arrangement applies; verify against the current Code tables rather than a rule of thumb. Private and street hydrants must be reachable by appliances, and inlet and outlet positions are agreed with FSD. Hose reels support first-aid attack and do not replace hydrant flow for the fire service.
Smoke control
Staircase pressurisation, protected lobby ventilation and smoke extract from atria and long corridors are the principal tools. Pressurisation is proven by measuring the differential across closed doors, the air velocity through an open door, and the door-opening force. Extract systems are proven by measured volumetric flow at the design points, not merely by a fan starting.
Emergency lighting and signage
Escape route lighting, exit signs and illumination of installation controls must remain operable on mains failure for the duration required by the Code, and battery or inverter systems need periodic discharge testing recorded in the maintenance log.
Worked example
A hose reel and hydrant system is designed for 1,200 L/min over 30 minutes. Tank volume = 1,200 × 30 = 36,000 L, before adding sprinkler demand if the two operate together. The pump curve is then checked so that at full draw-down the residual pressure at the topmost hydrant still meets the required outlet pressure; if it does not, either the pump selection or the tank elevation must change.
Traps
Adding every system's full flow to size the tank; omitting jockey set-points so the main pump short-cycles; commissioning pressurisation on fan start only; tenancy alterations that obstruct hose reel coverage; ignoring periodic certification after handover.