1. Mandatory components of a fire fighting system
A fire fighting pump system, per NFPA 20 and NBR 16704, consists of main and auxiliary components working together to ensure water pressure and flow at the moment of emergency.
- Main pump — horizontal centrifugal (FBCN series) or vertical, sized for design flow and pressure. Driven by electric motor or diesel engine.
- Jockey pump — pressure maintenance, ~1% of main flow. Maintains static pressure and prevents unnecessary main pump starts.
- Control panel — automation with pressure switches, protection relays, visual/audible signaling, direct start or soft-starter, and interface for building management system (BMS).
- Valves — check (prevents backflow), gate (isolation for maintenance), relief (overpressure protection).
- Instrumentation — pressure gauges, high and low pressure switches, flow meters, reservoir level sensors.
2. The 3 system configurations — electric, diesel and redundant
FB Bombas supplies three standardized configurations serving from small buildings to high-risk industrial plants:
| Configuration | Components | Typical application |
|---|---|---|
| Electric | Electric main pump + jockey + panel | Buildings with reliable power, shopping centers, hospitals with generator |
| Diesel | Diesel main pump + electric jockey + panel | Remote industrial plants, areas without reliable power |
| Electric + Diesel (redundant) | Electric main + diesel backup + jockey + panel | Refineries, petrochemical, NFPA special hazard |
3. Applicable standards: NFPA 20 and NBR 16704
NFPA 20 (Standard for the Installation of Stationary Pumps for Fire Protection) is the international reference standard for design, installation, operation and testing of stationary fire pumps. It defines requirements for main pump, jockey, diesel engine, control panel and acceptance testing.
In Brazil, NBR 16704 (Installation of stationary pumps for fire protection) adapts NFPA 20 requirements to the national context. Other complementary standards: NBR 10897 (sprinklers), NBR 13714 (hydrants and hose systems) and state Fire Department standards.
4. How to size the system — required data
Fire fighting system sizing starts from the building or plant risk analysis, which determines the occupancy class (light, ordinary or extra), protection type (sprinklers, hydrants or both) and water demand (flow and pressure).
- Design flow — defined by standard per risk class and coverage area (e.g., ordinary hazard II = 0.20 GPM/ft² over 1,500 ft²)
- Design pressure — residual pressure at most remote sprinkler or hydrant + piping friction losses + elevation difference
- Drive type — electric (induction motor), diesel (automatic start by pressure switch) or redundant
- Site conditions — electrical power availability, pump room space, water source (reservoir, cistern, public supply)
5. How the system starts on its own: the pressure-switch cascade
In normal operation the network stays pressurized and no pump runs. Automation works through descending pressure steps: a small drop — natural leakage, a micro opening — first triggers the jockey pump, which restores pressure and shuts off. If the drop continues, signaling real demand (open sprinkler, hydrant in use), the main pump's pressure switch commands a start at the next setpoint, below the jockey's.
In configurations with diesel backup, a third, even lower step starts the emergency pump if the main one fails to recover pressure.
A design detail that surprises first-time operators: the main pump starts on its own, but as a rule it does not stop on its own. The NFPA 20 philosophy is that, once fighting a fire, only the operator — assessing the situation on site — decides to end pumping. Shutdown is therefore typically manual at the controller, and the fire brigade team must be trained in this procedure.
6. The routine that keeps the system alive: testing per NFPA 25
A fire system sits idle for years and must work perfectly on the one day it is demanded — which is why its maintenance differs from a process pump's.
NFPA 25 is the inspection, testing and maintenance (ITM) standard for water-based protection systems: it defines the periodic no-flow exercise (the diesel pump typically runs 30 minutes weekly; the electric one, in shorter cycles), the annual flow test with measurement at the curve points, and the routine visual inspections in the pump room — valves locked open, fuel level, battery charger, room temperature.
Failures found during tests follow a known pattern: discharged or end-of-life batteries, aged diesel in the tank, an isolation valve someone closed and never reopened, and a miscalibrated pressure switch. None of them appears in a system that keeps the routine — all of them appear together in the system that went two years untested. The documented record of each exercise is, beyond a standard and insurer requirement, the technical memory that lets you see degradation coming.
7. FB Bombas integrated skid — ready to install
FB Bombas supplies fire fighting systems as integrated skids: metal base with main pump, jockey, motor (electric and/or diesel), control panel, valves, instrumentation and interconnecting piping. The assembly arrives at the site ready for connection to suction and discharge piping.
Integrated skid advantages: reduced field installation time, hydraulic and electrical tests performed at factory, single manufacturer warranty on entire system, and customized application engineering. Brazilian manufacturer since 1944, with experience in projects for Petrobras, Vale, BASF, CSN and dozens of industrial plants.
