1. What NBR 16704 is and when it applies
ABNT NBR 16704 is the Brazilian standard specific to stationary fire protection pump sets — the document defining how to select and install the main pump, the standby pump and the jockey pump that pressurize automatic fire systems. Published in 2019 (with a corrected version in 2020), it nationalized for the Brazilian context the requirements of the international NFPA 20 standard, which remains the design reference cited in the Fire Department Technical Instructions.
The declared scope is liquid supply for automatic protection systems — automatic sprinklers (designed per NBR 10897) and water spray systems. In design practice, the same pump set frequently also feeds the NBR 13714 hydrant network, and engineering sizes the set for the combined demand defined in the hydraulic design.
The division of roles in the standard family is direct: NBR 10897 and NBR 13714 say how much water the system needs (demand flow and pressure); NBR 16704 — with NFPA 20 — says how the pump set must be built, installed and tested to deliver that demand with life-safety system reliability.
2. Which pumps the standard accepts — and the role of each
NBR 16704 applies to centrifugal pumps, single-stage or multistage, with horizontal or vertical shaft, driven by electric motor or diesel engine. The dominant configuration in Brazilian projects is the single-stage horizontal end-suction centrifugal — at FB Bombas, the standardized FBCN series, with back pull-out disassembly allowing maintenance without disconnecting piping.
The complete set has three distinct functions. The main pump meets the total system demand. The standby pump — required according to project criticality — takes over when the main fails or the primary power source drops; hence the classic electric main + diesel standby combination.
The jockey pump is the third piece: a small, low-flow pump with pressure equal to or above network working pressure, compensating micro-leaks and keeping the network pressurized so the main does not start at every oscillation — NFPA 20 guides sizing it around 1% of the main pump flow.
3. The performance curve the set must meet
The technical heart of the standard is hydraulic performance. Following the envelope established by NFPA 20, the fire pump must deliver 100% of design flow at design pressure; maintain, at 150% of flow, at least 65% of design pressure; and cap shutoff pressure (zero flow) at 140% of design pressure. This flat curve ensures the system keeps delivering usable water even when actual demand exceeds design — the typical scenario of a real fire with more open heads than calculated.
For the buyer this changes the selection criterion: it is not enough for the pump to "hit the point" — the whole curve shape must fit the envelope. Catalog pumps selected only by nominal point frequently fail the second criterion (150%/65%), and the failure only appears at testing, when replacing the pump is expensive. That is why the factory-certified curve, measured on the bench for the actual pump supplied (not the generic catalog curve), is the central acceptance document.
4. Tests and documentation: what proves compliance
NBR 16704 dedicates a relevant part of its text to performance and acceptance testing — because a life-safety system is not approved by declaration, it is approved by evidence. In the FB Bombas flow, that evidence is built in two stages. At the factory: certified pump curve measured on the bench and set FAT (Factory Acceptance Test), including hydrostatic testing of internal piping at 1.5× operating pressure, panel verification and instrument calibration.
In the field: commissioning confirms automatic starts at the pressure switch setpoints and performance at the duty point.
The dossier shipping with the set closes the cycle: certified curve, FAT report, project liability note (ART), operation manual, parts list and AS-BUILT drawings. This is exactly the package the Fire Department inspection (per the state Technical Instruction) and the insurer audit request at system acceptance — and any missing item is a recurring cause of pending status on the fire certificate.
5. NBR 16704 × NFPA 20: how the two coexist in Brazilian projects
The most common specification question is "do I follow NBR 16704 or NFPA 20?" — and the correct answer is "both, in different roles". NBR 16704 is the Brazilian standard, built on the technical basis of NFPA 20, and the natural reference for ABNT compliance in national licensing. NFPA 20 remains the international vocabulary of the sector: global insurers, multinational industrial projects and large EPC specifications keep citing NFPA 20 explicitly.
In buying practice: your state Fire Department Technical Instruction defines which reference licensing accepts (many cite both), the designer specifies the performance envelope — which is the same in both standards — and the manufacturer proves it by testing. A well-specified set meets both simultaneously; there is no technical conflict between them, there is jurisdictional complementarity.
6. Mistakes that fail approval — and the correct specification path
The four most common mistakes in designs reaching application engineering: selecting the pump by nominal point without checking the full curve envelope (fails at 150%/65%); forgetting the jockey pump or setting it with the wrong setpoint (the main cycles at every micro-leak); treating the set as loose parts from different suppliers (at inspection, nobody answers for the whole); and buying without the acceptance dossier agreed in contract (the certified curve and the test report are not optional — they are what approves the system).
The correct path is linear: demand from the system standards (NBR 10897 and NBR 13714, or the water spray design), NBR 16704/NFPA 20 performance envelope, driver configuration by criticality (electric, diesel or combined) and acceptance dossier defined with the order. FB Bombas application engineering walks this path from the project data and returns the complete skid set specification — pump, jockey, panels, certified curve and inspection documentation.
