1. Skid components and boundaries
NFPA 20 calls the skid a packaged fire pump assembly: fire pump unit components assembled at a packaging facility and shipped as a unit to the installation site. Where the standard requires listing, the scope of listed components includes the pump, driver, controller and other accessories identified by the packager, assembled onto a base with or without an enclosure (3.3.52.13).
FB Bombas FBFS assemblies come in three configurations, electric, diesel and electric plus diesel, with the FBCN normalized centrifugal pump as the main pump. The electric set has an electric motor-driven main pump, a jockey pump for pressure maintenance and automatic controls. The diesel set has a diesel engine-driven main pump, a jockey pump and a dedicated controller, and the project defines the starting system, fuel tank, ventilation, cooling and exhaust.
The combined set brings together an electric motor-driven pump and a diesel engine-driven pump, plus the jockey pump and controls for each driver.
The FBCN manual (MTEC-03/00, p.8) lists the pump set accessories: electric motor or diesel engine drive, flexible coupling with or without spacer, FB standard or from other manufacturers, coupling guard in carbon steel or non-sparking material, and a welded structural steel base. The connection table (p.12) provides 1/4″ NPT taps for the pressure gauge and the compound gauge and a 1″ NPT base drain.
The Brazilian rules cited on this page are São Paulo IT 22, Goiás NT 22 and NBR 13714. They require a pressure gauge on the main pump discharge and, where the pump operates under negative suction, a compound gauge on the suction (IT 22, C.1.17; NT 22, C.1.17; NBR 13714, B.1.15). Where the contract adopts NFPA 20, the discharge gauge has a dial of at least 3.5 in. (89 mm), is connected near the discharge casting with a 0.25 in.
(6 mm) gauge valve and reads to at least twice the rated working pressure, never less than 200 psi (13.8 bar). There is also a suction gauge near the pump, and it is a compound pressure and vacuum gauge where the minimum suction pressure is below 20 psi (1.3 bar) at any flow (4.12).
The pressure switches that start and stop the jockey pump and only start the main pump follow the automation manifold shown in the rules and are wired to the controllers and motor starters of each pump (IT 22, C.1.15.2; NT 22, C.2.3; NBR 13714, B.1.13.2). Under NFPA 20, each controller, including the jockey pump controller, has its own pressure sensing line, connected between that pump’s discharge check valve and discharge isolation valve.
The line is brass, rigid copper pipe Type K, L or M, or Series 300 stainless steel, with 1/2 in. (15 mm) nominal fittings, has no shutoff valve and carries two inspection test valves (4.32.1 to 4.32.6). For dampening, the standard calls for two bronze or stainless steel check valves at least 5 ft (1.52 m) apart, with a 3/32 in.
(2.4 mm) hole drilled in the clapper; with clean water, it permits ground-face unions with drilled noncorrosive diaphragms instead (4.32.4).
Where the contract adopts NFPA 20, each fire pump has a listed automatic circulation relief valve on the discharge side, before the discharge check valve: 0.75 in. (19 mm) up to 2,500 gpm (9,462 L/min) and 1 in. (25 mm) from 3,000 to 5,000 gpm (11,355 to 18,925 L/min), set below the shutoff pressure at the minimum expected suction pressure and discharging visibly to a drain (4.13).
It is not required for an engine-driven pump whose engine cooling water is taken from the pump discharge (4.13.1.2). Jockey pump suction and discharge piping is steel, including in packaged prefabricated systems, with an isolation valve on the suction and a check valve and isolation valve on the discharge (4.27.6).
The supply list identifies each item of equipment, piping, valve, instrument and connection included and what is left to site installation; the word complete does not replace it. Check at least:
- main pump: model, impeller diameter, speed and curve;
- driver, coupling and coupling guard;
- jockey pump, controllers and pressure switches;
- isolation, check and circulation relief valves;
- pressure gauges, compound gauge and pressure sensing lines;
- base, lifting points and, where supplied, the enclosure;
- for diesel, the fuel, starting, cooling and exhaust items mounted on the assembly.
2. Assembly requirements and site services
Where the contract adopts NFPA 20, the packaged assembly meets five requirements (4.31.1): components assembled and affixed onto a steel framing structure; welders qualified in accordance with Section 9 of the ASME Boiler and Pressure Vessel Code or AWS D1.1/D1.1M, Structural Welding Code — Steel; an assembly listed for fire pump service; the total assembly engineered and designed by a system designer, who is identified on the system design documents (4.3.2); and all plans and data sheets submitted to and reviewed by the authority having jurisdiction, with copies of the stamped approved submittals used in the assembly and kept for record.
Electrical components, clearances and wiring meet the applicable NFPA 70 articles (4.31.2). The skid also meets every other requirement of the standard, including equipment protection, pipe and fittings, suction and discharge piping, valve supervision and protection of piping against damage due to movement (4.31.3, which refers to Sections 4.14 through 4.19).
The listing belongs to the assembly and is issued by an organization acceptable to the authority having jurisdiction; a design that conforms to NFPA 20 does not replace it. If the specification calls for a listed assembly, ask for the document of the assembly offered. The standard also requires a single entity to be responsible for acceptable unit performance of the pump, driver, controller and transfer switch equipment (4.4.3). Name that entity in the contract.
The site prepares the foundation, access, piping, power and drainage to the drawings, and preassembly does not remove these interfaces. Comparing proposals therefore starts with scope: procurement, assembly, transport, installation and testing included in each.
Timing and costs require a specific proposal. There is no universal saving percentage or guarantee of same-day installation and acceptance.
Key point
List interfaces and responsibilities before ordering. This helps identify omitted services when comparing suppliers.
3. Transport, setting and alignment
NFPA 20 requires careful consideration of possible damage during shipment to the site: structural integrity is maintained with minimal flexing and movement, and the necessary supports and restraints are installed to prevent damage and breakage in transit (4.31.4). The correct lifting points are marked on the assembly for safe rigging (4.31.5). Record the condition on receipt before installation: identification, components, integrity and shipping documents.
Once the skid is set on the permanent foundation, the suction and discharge piping is thoroughly inspected, including every flanged and mechanical connection, per the manufacturers’ recommendations (4.31.7).
The assembly is anchored and grouted in accordance with Section 6.4 (4.31.8): pump and driver on a common grouted base plate per the manufacturer’s instructions; the base plate securely attached to a solid foundation so that shaft alignment is ensured; a foundation substantial enough to form a permanent and rigid support; and the base plate set level (6.4.1 and 6.4.3 to 6.4.5).
A separately coupled pump with an electric motor or diesel engine is connected to the driver by a flexible coupling or flexible connecting shaft, listed for fire pump service and installed in accordance with the listing (6.5.1). Alignment follows the coupling and pump manufacturers’ specifications and ANSI/HI 1.4, the installation, operation and maintenance standard for rotodynamic pumps (6.5.2).
Under the Brazilian rules, the main pump is directly coupled through a flexible coupling, without belts or chains (IT 22, C.1.5; NT 22, C.1.6; NBR 13714, B.1.5).
An alignment done before shipment does not replace a check after transport and anchoring. Record the procedure and the measured values; do not claim micrometer precision or laser alignment without the corresponding record. Factory testing also does not reproduce site suction and power conditions.
Where the supply includes a packaged pump house, the interior floor is of solid construction, graded to drain the fire pump components, and the structural frame sits on an engineered footing designed for the live loads of the unit and the applicable wind loads, with the anchor points needed to secure it (4.31.9).
The standard permits a highly skid-resistant solid structural plate floor with grout holes where corrosion protection and drainage are provided for incidental pump room spillage or leakage (4.31.10).
4. Documentation, testing and acceptance
On receipt, check the nameplates against the data sheet and the curve. Under the Brazilian rules, each main or booster pump has a nameplate with the manufacturer’s name, serial number, pump model, rated flow, rated pressure, operating speed and impeller diameter, and the electric motor has a nameplate with manufacturer, type, model, serial number, power in CV, speed, voltage, current and frequency (IT 22, C.2.15 and C.2.16; NT 22, C.4.12 and C.4.13; NBR 13714, B.2.9 and B.2.10).
Under NFPA 20, the nameplate is made of and attached with corrosion-resistant material and indicates the maximum pump horsepower demand at any flow, including flows beyond 150% of rated capacity (4.11).
The electric pump controller is supplied with dimensional drawings, layout, electrical diagram, terminal strip, internal wiring diagram and a list of the materials used (IT 22, C.2.18.4; NT 22, C.4.17; NBR 13714, B.2.14). Manuals, a component list and reports complete the file; for Brazilian projects, clarify the engineering responsibilities and registrations required for each service.
Where the contract adopts NFPA 20, the manufacturer furnishes the purchaser with certified shop test curves showing head capacity and brake horsepower (4.5.1). Each pump is tested at the factory to provide detailed performance data and demonstrate compliance with specifications (4.24.1) and, before shipment, is hydrostatically tested for at least 5 minutes at no less than one and one-half times the sum of its shutoff head and maximum allowable suction head, never below 250 psi (17.24 bar) (4.24.2).
Define factory and site tests, criteria, participation and reports in the contract. FAT and SAT require scope and records, not just labels.
Acceptance applies to the whole unit. Under NFPA 20, the pump, driver and controller perform in compliance with the standard as an entire unit when installed or when components are replaced (4.4.1), and the complete unit is field acceptance tested once the entire installation is finished (4.4.2 and 4.34).
The Section 6.2 performance criteria apply in the factory and in the field: at least 150% of rated capacity at no less than 65% of total rated head, and a shutoff head of no more than 140% of rated head.
Building approval, such as the AVCB in São Paulo, is separate from skid acceptance. The proposal must not promise automatic approval by the authority or the insurer.
5. Preparing your FB Bombas enquiry
Send design flow and pressure, water source and suction condition, electric or diesel supply, the adopted standard and the authority having jurisdiction, with the pump room and access drawings. NFPA 20 requires the pump manufacturer to be given complete information on the liquid and power supply characteristics (4.2.2).
FB Bombas defines deliverables per project, such as data sheet, Q×H curve, dimensional drawing, FAT plan and bench test certificate. At its Cabreúva-SP factory it performs CNC machining, assembly and hydraulic bench testing to ANSI/HI 14.6; supply, shipping, testing and site service are confirmed in the proposal.
For replacement or retrofit, send nameplate photographs, curves and existing drawings. Assess compatibility and interfaces before defining replacements.
Engineering note
A useful proposal identifies the assembly, the selection documents and the tests as well as commercial terms.