Fire Pumps for Warehouses and Logistics Facilities

1. Storage classification and the rules that apply

In São Paulo, the state Fire Safety Regulation (State Decree No. 69,118) classifies storage buildings in group J by fire load: J-1 for non-combustible material without packaging, J-2 up to 300 MJ/m², J-3 above 300 and up to 1,200 MJ/m², and J-4 above 1,200 MJ/m², which includes assorted combustible recyclable materials. The division sets the required fire safety measures; the fire pump comes afterwards, sized for the systems those measures call for.

For divisions J-3 and J-4 with more than 750 m² or more than 12 m in height, Table 6J-2 of the regulation requires hydrants and hose reels in every height band and automatic sprinklers above 12 m; up to 30 m, the required horizontal compartmentation may be replaced by automatic sprinklers.

Height, in this regulation, runs from the lowest occupied floor to the floor of the top storey, and a building with a single storey, even with a mezzanine, counts as single-storey whatever its clear height. In a single-storey warehouse of these divisions, therefore, the table does not require sprinklers by height: they come in when they replace horizontal compartmentation (note 1) or under a specific-risk requirement of another Technical Instruction (general note c).

Where sprinklers are required, IT 23 sends storage buildings to IT 24, and the same applies to group C commercial buildings with storage above 3.70 m. IT 24 applies to all storage areas where sprinklers are required, except those holding flammable or combustible liquids, and was prepared on the basis of NFPA 13.

In Goiás, NT 23 sends any storage, even temporary and of any height, to NBR 16981, and treats commercial buildings with display fixtures above 3.7 m as storage.

For the pump, the data that matter come from the sprinkler design: commodity class, arrangement (pallets, solid piles, bin boxes, shelves or racks), storage height and building clear height, which IT 24 measures from the floor to the underside of the ceiling or roof at its highest point. The IT 24 criteria apply only to roofs with a slope of up to 16.7%.

A change of commodity, arrangement or height calls for a new assessment by the designer: a curve chosen for the previous operation does not establish suitability for the new scenario.

2. Main, standby and jockey pumps: what each rule requires

The main pump supplies the design firefighting demand. In São Paulo, sprinkler pump sets follow Annex C of IT 22 and NBR 16704 (IT 23, 7.5). That annex calls for at least one electric or internal combustion pump, used only for firefighting, directly coupled through a flexible coupling, without belts or chains, with an isolating valve upstream and a check valve plus another isolating valve downstream (C.1.1, C.1.3 and C.1.5).

Once started, the pump is stopped only manually, at its own controller in the pump room; with an automated pump, there is at least one manual start point in a safe, easily accessible location; and the pump reaches full speed in approximately 30 s (C.1.6, C.1.7 and C.1.9).

A standby pump is not automatic in every warehouse. Where the contract adopts NFPA 20, the electric pump needs an alternate power source where the normal source is not reliable or in a high-rise building, and that source is not required with a backup engine-driven, steam turbine-driven or electric pump with an independent power supply (9.3.1 and 9.3.2); the alternate source can be a generator or another source independent of the normal one (9.3.3).

Under IT 22, if utility power fails, the electric pump may be supplied by a diesel generator under the conditions of C.2.8 (C.2.9), and where there is only one combustion engine pump, its starting is always automatic (C.3.12). In Goiás, with combined hydrant and sprinkler systems, NT 23 exceptionally accepts a single combustion engine pump for both systems, provided there is a standby starting method from stationary batteries, triggered automatically if the main method fails (5.8 b).

The jockey pump keeps the network pressurized and makes up small losses, without replacing the main pump. Under IT 22, hydrant or hose reel networks with more than six outlets take a jockey pump of no more than 20 L/min, waived where the fire reservoir is elevated; its maximum pressure equals the main pump’s shutoff pressure, and about 10 m of water column between the sequential pump starts is recommended (C.1.15 and C.1.15.1).

For systems with only aboveground sprinkler and standpipe piping, the NFPA 20 annex recommends a jockey flow less than that of a single sprinkler, so that the main pump starts when a sprinkler opens.

The main pump’s signalling panel has a manual start push-button and visual and audible signals. For an electric pump, it shows at least panel energized, pump running, phase failure and loss of power to the starting circuit; for a combustion engine pump, panel energized, pump running, low battery charge and selector in manual or panel off (IT 22, C.1.16).

The proposal should identify each pump, its driver, the control logic and the interfaces: the number of units alone does not establish redundancy.

3. Sprinkler and hydrant demand, pump curve and suction

IT 24 separates two paths. With density/area control sprinklers, the design density is never less than 6.1 L/min/m², and the design area is never less than 186 m² for wet pipe or 242 m² for dry pipe systems (5.2.2.1.3.1); in dry pipe and preaction systems, that area increases by 30%, up to no more than 557.4 m² (5.1.6.7 and 5.1.6.8).

For palletized, solid-piled, bin-box or shelf storage, the reserve lasts from 90 minutes (Class I to III above 3.7 m and up to 6.1 m) to 150 minutes (Class IV above 6.1 m and up to 9.1 m, and Group A plastics above 6.1 m and up to 7.6 m) (Table 5.2.1.2).

For rack storage, the dedicated tables call for 90 minutes for Class I to III and 120 minutes for Class IV; tires (5.4) and temporary storage (5.1.10) also have their own tables.

With ESFR sprinklers, the design area includes the 12 hydraulically most demanding sprinklers, formed by 4 sprinklers on 3 branch lines, with at least 89 m² (5.2.2.3.3). The minimum operating pressure comes from the IT 24 table by commodity, maximum storage height and maximum ceiling height, and the hydraulic calculation uses the K-factors the IT gives in parentheses, such as 200 for K-14.0 and 360 for K-25.2 (5.1.1.4).

ESFR is used only in wet pipe systems and in buildings with a height equal to or lower than the height for which the sprinkler was certified (5.1.4.9 and 5.1.2.8). The table at the end of this section shows, for one row of IT 24, how the K-factor trades pressure for flow.

Hydrant demand is added to sprinkler demand. Under IT 23, the hydrant demand enters the hydraulic calculation and the water reserve together with the sprinkler demand, meets Table 2 of IT 22 even where the systems are independent, and the effective reserves are added together (10.4.1.1, 10.4.1.2 and 8.2).

In IT 22, sizing considers the two most unfavourable jets in simultaneous use, each with at least the Table 2 flow (4.8.3): 200 L/min in a type 3 system, 300 L/min in type 4 and 600 L/min in type 5, with double outlets.

In Table 3, J-3 storage goes to type 3 up to 800 MJ/m² and to type 4 above that, and J-4 to type 4 up to 5,000 m² and to type 5 above; note 1 allows type 4 where a type 5 occupancy is required to have sprinklers.

With the combined demand at the connection point, the curve comes in. Where the contract adopts NFPA 20, the centrifugal pump delivers at least 65% of rated pressure at 150% of rated flow, and a shutoff of no more than 140% of rated pressure, for any type of pump (6.2.1 and 6.2.2).

Under IT 22, the capacity of the main pump in flow and pressure meets the demand according to the criteria adopted, and pumps above 100 m of water column (1 MPa) are not recommended (C.1.13 and C.1.14). Ask for the curve of the offered model, impeller and speed, and do not turn a maximum catalogue flow into a guaranteed duty point: pressure, power and suction must correspond to the same selection.

Suction closes the selection. In São Paulo and Goiás, the sprinkler pump must operate under positive pressure, with no priming tank (IT 23, 7.5.1; NT 23, 5.18); IT 22 defines positive suction as the pump shaft below water level X, allowed up to 2 m above it or at 1/3 of the reservoir’s effective capacity, whichever is less (C.1.12).

Where the contract adopts NFPA 20, the centrifugal pumps of that chapter are not used where a static suction lift is required (6.1.1.4), and the suction pipe is sized so that the gauge pressure at the suction flange stays at 0 psi (0 bar) or higher with all pumps at maximum flow: 150% of rated flow or the maximum the water supply can deliver at the lowest permissible suction pressure (4.16.3.1).

The exception is a suction tank whose water level, after supplying the most demanding system for the required duration, is at or above the pump centerline: the pressure may then drop to −3 psi (−0.2 bar) at 150% of rated flow, with the tank at its lowest level (4.16.3.2).

4. Pump room and skid

Where the contract adopts NFPA 20, the pump, driver, controller, water supply and power supply are protected against interruption of service by explosion, fire, flood, earthquake, rodents, insects, windstorm, freezing, vandalism and other adverse conditions (4.14.1).

In a non-high-rise building, the indoor pump room is separated from the warehouse by 2-hour fire-rated construction or 15.3 m (50 ft) when the warehouse is not sprinklered, and by 1 hour or 15.3 m when both are fully sprinklered in accordance with NFPA 13 or NFPA 13R (Table 4.14.1.1.2).

The pump room itself is sprinklered in accordance with NFPA 13: Extra Hazard Group 2 where it encloses a diesel engine or its fuel tank, and Ordinary Hazard Group 1 with an electric motor (4.14.1.3). Outdoor units are located at least 15.3 m from buildings and other fire exposures (4.14.1.2.1).

The location of and access to the pump room are preplanned with the fire department; where there is no direct access from outside, access is through a fire-resistance-rated corridor from an enclosed stairway or exterior exit (4.14.1.1.4 and 4.14.2.1.1). The room is kept free from storage, equipment and penetrations not essential to the pump, with domestic water equipment permitted, and has room for the installation and maintenance clearances between components and to the wall (4.14.1.1.5 to 4.14.1.1.7).

NFPA 20 also requires heat to keep the room above 4 °C (40 °F) where required, normal lighting, emergency lighting of 32.3 lux (3.0 ft-candles) for at least 2 hours, unless the authority specifies otherwise, not connected to an engine-starting battery, ventilation, a pitched floor, a floor drain to a frost-free location and a coupling guard (4.14.3 to 4.14.8).

The Brazilian rules ask for the same care. Under IT 22, the pump room allows access all around the pumps, local maintenance and complete removal of any pump; if buried or in a manifold space, it has access at least by a fixed ladder, and the manifold space has at least 1.5 m of headroom (C.1.2 and C.1.2.1).

The pumps are protected against mechanical damage, weather, chemicals, fire or humidity, and do not share the room with other machines, except those of water-based fire protection systems and the building’s domestic water pumps (C.1.4 and C.2.5). In the IT 23 sample inspection report, the inspector checks that the pump is in a fire-protected compartment with no accumulated combustible materials (Annex C, 4.4 and 4.5).

On the skid, pump and driver sit on a common grouted base plate, in accordance with the manufacturer’s instructions, attached to a solid foundation that ensures shaft alignment (NFPA 20, 6.4.1 and 6.4.3).

Each pump has an automatic circulation relief valve listed for fire pump service, installed before the discharge check valve, set below shutoff pressure at the minimum expected suction pressure and discharging visibly to a drain, except in the cases the standard exempts (4.13.1, 4.13.3, 4.13.5, 4.13.8 and 4.13.10); IT 22 requires pumps with a rated flow above 600 L/min to have a continuous flow through a 6 mm pipe or orifice plate taken from the volute, to prevent overheating (C.2.18.7).

Separate supply, installation and commissioning in the contract, with each party’s hydraulic, electrical and civil interfaces.

5. Factory tests and field acceptance

At its Cabreúva-SP factory, FB Bombas performs CNC machining, assembly and hydraulic bench testing to ANSI/HI 14.6. Depending on the project, the documentation includes a data sheet, Q×H curve, dimensional drawing, FAT plan and bench test certificate; the tests and documents for each supply are defined in the proposal. The IT 23 sample inspection report asks whether the flow-versus-pressure performance curve prepared by the manufacturer before installation was presented (Annex C, 4.2).

In the field, where the contract adopts NFPA 20, the acceptance test uses calibrated equipment for net pump pressures, flow, volts, amperes and speed, labelled with the latest calibration date, calibrated at least annually and kept to an accuracy of ±1%; voltage and current readings from controllers factory calibrated to ±2% may replace the meters.

The annex sample procedure names 150% of rated flow, rated flow and shutoff as the important test points, and at each point it records speed, suction and discharge pressures, flow, amperes and volts; for a diesel drive, also engine back pressure, oil pressure, cooling loop water pressure and engine temperature. The evaluation checks that the discharge flow and pressure are adequate to supply the fire protection demand.

In São Paulo, IT 23 recommends that, after the sprinkler system is installed, the professional responsible for the installation fill in the Annex B commissioning report, obtain the signature of the owner or occupant and keep it with the construction records.

Under the annex procedure, the installer completes the work, inspection and tests witnessed by someone acting for the owner, and all problems are resolved, with the system placed in service, before the installer leaves the site; the form also records the pressure and duration of the piping hydrostatic test.

A hydrostatic test checks a different condition from a hydraulic performance test, and one report does not automatically demonstrate the other. Technical acceptance of the assembly and approval of the building also have different scopes: supplying the pump does not guarantee approval of the facility.

6. Inspection, testing and maintenance while the warehouse operates

Where the contract adopts NFPA 25, a diesel pump gets a no-flow test every week, and most electric pumps every month.

An electric pump goes back to weekly testing when it serves a building beyond the fire department’s pumping capacity, has a limited service controller, is a vertical turbine pump, or takes suction from a ground-level tank or from a source without useful pressure without the pump, unless a redundant fire pump is provided; both frequencies can be extended by an approved risk analysis.

In a warehouse with a ground-level tank, therefore, the electric pump drawing from it stays on weekly testing unless there is a redundant pump. The test starts automatically, by draining water from the pressure sensing line to simulate a system pressure drop, and the pump runs for at least 10 minutes if electric or 30 minutes if diesel.

Qualified personnel attend the pump while it runs, unless inspection and testing are automated in accordance with the standard. During the test, it is confirmed that the circulation relief valve discharges a small flow of water; once a year, the flow test verifies the complete operating condition of the pump, and diesel fuel is tested annually. Compare the results with those from commissioning and log every intervention.

In São Paulo, when the inspection certificate is renewed, IT 23 recommends that the professional responsible for maintenance fill in the Annex C inspection report, signed by the owner or occupant and kept on file in the building.

In the pump block, the report asks whether there is a performance curve produced in the last 36 months, whether flow and pressure follow the approved design, whether the isolating valves, except those on the test header, are locked fully open, whether there is a flow meter and a test header for the annual test, and whether the alarm panel reports the NBR 10897 Annex B events for pump supervision (Annex C, 4.3, 4.7, 4.8 and 4.10 to 4.12).

Plan how protection will be maintained during work on the pump or the network, and how an impairment will be communicated to warehouse operations. New demands, changes of commodity or arrangement, and alterations to the reservoir or network require technical assessment before operations change.

7. Fire department, insurer and assembly documents

Under IT 22, each main or booster pump has a nameplate with the manufacturer, serial number, model, rated flow, rated pressure, operating speed and impeller diameter; the electric motor and the combustion engine have their own nameplates, and the controller is supplied with dimensional drawings, layout, wiring diagram, terminal strip, internal wiring diagram and a list of materials (C.2.15, C.2.16, C.3.8 and C.2.18.4).

The electric pump’s supply switch is marked “ALIMENTAÇÃO DA BOMBA DE INCÊNDIO – NÃO DESLIGUE” (fire pump supply – do not switch off) (C.2.11).

Record the insurer’s and purchaser’s requirements in the enquiry, such as listed or approved components, and ask for the documents of the offered model where they are required: citing a standard does not prove a listing or an approval, and NFPA and ABNT publish standards; they do not certify products. NFPA 20 requires listing for specific items, such as the automatic circulation relief valve (4.13.1).

In IT 24, specific-application sprinklers are accepted only when certified by a laboratory of recognized national or international competence, with reports and catalogues in Portuguese or with a sworn translation (5.1.1.7 and 5.1.1.7.1).

Send the hydraulic calculation report, the pump room layout, the power supply data and the local authority’s requirements, with the list of documents that must accompany the assembly and who is responsible for each stage.

FB Bombas assesses the proposal from these inputs and, after the sale, offers start-up and commissioning based on the manual and site conditions, bench performance testing with a scope defined for the project, and maintenance contracts for FB lines; service format, checks, acceptance criteria and records are defined in the proposal. Lead time, testing and site services are confirmed for each supply.