Fire pump selection starts with the system demand, not a catalog. The designer fixes the flow and pressure the sprinkler and standpipe systems need, chooses a listed pump whose curve covers it, adds the controller and driver, lays out the pump room to NFPA 20, and builds a submittal the consultant and the authority having jurisdiction (AHJ) can check.
Key takeaways
- Size the pump on the highest single demand it serves, at no more than 150% of rated flow, with the duty point ideally mid-curve.
- Horizontal pumps need positive suction; where water is below the pump, a vertical turbine pump is used.
- NFPA 20 requires a listed pump and a controller listed for fire pump service; FM 1311 covers split-case pumps only.
- Churn plus maximum static suction pressure must not exceed system component ratings.
- Submit the curve, listing evidence for the exact model, driver and controller data, drawings, calculations and the certificate of conformity.
In this article
- From demand to duty point: sizing flow and pressure
- Fire pump types and where each fits
- Choosing the controller and driver
- Pump room and piping layout basics
- The submittal package reviewers expect
- Approvals in Saudi Arabia: consultant, Civil Defense and conformity
- Common mistakes and what drives cost
- How AZEIDK helps
- FAQ
From demand to duty point: sizing flow and pressure
The pump serves the system with the highest demand; demands are added only where the design says systems operate together. Flow comes from the hydraulic calculations: the sprinkler design area under NFPA 13 plus the hose allowance, or the standpipe demand under NFPA 14 where standpipes share the pump, whichever governs.
For pressure, the pump adds the difference between the pressure needed at its discharge (demand pressure plus losses to the most remote outlet) and the minimum suction pressure. With a ground-level or underground tank, common in Saudi buildings, use the lowest design water level, not a full tank.
2026 guidance from the American Society of Plumbing Engineers (ASPE) summarizes the NFPA 20 framework:
- The highest single system demand must not exceed 150% of the pump’s nameplate flow.
- It is recommended to keep the duty point below about 140% of rated flow, where suction conditions start to dominate, and above about 90%.
- NFPA 20 sets the curve shape: rated pressure at rated flow, 150% of rated flow at 65% or more of rated pressure, and churn between 101% and 140% of rated pressure, as the Hydraulic Institute explains.
Check the top end too. Under Section 4.7.7.1 of the 2025 edition, as cited in a US AHJ plan review checklist, churn plus maximum static suction pressure must not exceed the component rating, typically 175 psi (12.1 bar). If it does, choose a flatter curve or higher-rated components; a relief valve does not replace correctly rated components in normal operation.
Fire pump types and where each fits
| Type | Typical fit | What to check | FM standard |
|---|---|---|---|
| Horizontal split-case | Larger flows; rugged two-bearing design | Larger footprint, rotation fixed at order, strict suction rules near the flange | FM 1311 |
| End-suction | Smaller flows, lower first cost | Bearings carried by the motor or frame; impeller removal means removing the motor | FM 1319 |
| Vertical in-line | Least floor space, small flows | Lifting gear may be needed for the rotating assembly | FM 1371 (single-stage) |
| Vertical turbine | Water below the pump: wells, sumps, underground tanks | Bowl submergence and pumping level; removal often needs a crane or roof hatch | FM 1312 |
Horizontal pumps run with positive suction. Where the water source sits below the pump discharge centerline and its pressure cannot bring water to the pump, a vertical turbine pump is used. UL 448 covers stationary centrifugal fire pumps in general, while FM examines each type to its own standard.
Choosing the controller and driver
The driver is an electric motor or a listed diesel engine; see our electric vs diesel fire pumps comparison. Good practice is to size it for the pump’s power up to 150% flow.
The controller must be listed for fire pump service, factory assembled and tested, start the pump automatically on pressure drop, and give local signals and remote monitoring contacts. UL 218 covers electric motor, diesel engine, limited service and medium voltage controllers, including units with an integral automatic transfer switch; FM uses FM 1321 and FM 1323.
- Electric starting methods: across-the-line, part winding, primary resistor, autotransformer, wye-delta, soft start and variable frequency drive. Reduced-voltage starting is recommended where the utility supply or generator cannot accept a full across-the-line start.
- Diesel controllers: two independent battery banks used alternately, a fixed attempt-to-start sequence and automatic weekly testing.
- Limited service controllers serve small motors; use them only where the adopted NFPA 20 edition, the specification and the AHJ allow.
Pump room and piping layout basics
Separation ratings and diesel items are in our fire pump room guide. At design stage, plan for these NFPA 20 (2025 edition) items; clause numbers are from the same checklist:
- A dedicated room without non-essential equipment or penetrations (4.14.1.1); outdoor pumps at least 50 ft (15.3 m) from the building (4.14.1.2.1).
- Floors pitched to drains (4.14.7); NFPA 20 also requires heat above 4°C (40°F) where needed and emergency lighting (4.14.5.1, 2019 text, unchanged in 2025); removal space is good practice.
- Suction: a listed outside screw and yoke (OS&Y) gate valve (4.16.5.1), no pressure regulating valve (4.16.9.1), an anti-vortex plate at the tank outlet (4.16.10), correct pipe size within 10 pipe diameters of the flange (4.16.3.3), and net positive suction head (NPSH) available at 150% flow (4.16.3.1).
- Discharge: listed check and indicating valves (4.17.7, 4.17.8), and a bypass where the supply has useful pressure (4.16.4).
- Testing: a test header or flow meter loop (4.22), and pressure sensing lines per Section 4.32.
- No fire department connection on the pump suction side (4.16.11).
The submittal package reviewers expect
NFPA 20 Section 4.2.3 lists the content of working plans, including pump make and model, curve and driver data. Reviewers usually need:
| Document | What it shows | What reviewers check |
|---|---|---|
| Pump data sheet and certified curve | Rated flow, pressure, speed and curve points | Fit with the duty point; listing covers this size and speed |
| Listing evidence | UL 448 listing or FM Approval for the exact model | The official directory record, not a catalog logo |
| Driver data | Driver rating and listing | Power across the curve; diesel derating for heat and altitude |
| Controller data | Listing, starting method, any transfer switch | Voltage, power, signals to the fire alarm panel |
| Hydraulic and suction calculations | Demand; NPSH available at 150% | 150% limit, lowest tank level, churn vs component ratings |
| Pump room drawings | Layout, valves, test header, drainage | Service clearances, separation, access |
| Certificate of conformity | Conformity with the Technical Regulation for Fire Control Materials and Equipment | The certificate covers the model supplied |
A catalog line saying “UL and FM approved” is not enough; listings cover a specific model, size and speed, as our listed and approved equipment submittal guide explains.
Approvals in Saudi Arabia: consultant, Civil Defense and conformity
Under Article 10 of the Implementing Regulation of the Saudi Building Code Law, the General Directorate of Civil Defense monitors and enforces the code’s fire prevention and protection requirements in construction, maintenance and operation. The Saudi Fire Protection Code (SBC 801) has a fire pump section (Section 913 in the 2018 and 2024 editions; the 2024 edition has been mandatory since 30 June 2025), and SBC 801 and Civil Defense set the NFPA 20 edition that applies; see our NFPA 20 guide.
Fire pumps also fall within the Technical Regulation for Fire Control Materials and Equipment of the Saudi Standards, Metrology and Quality Organization (SASO), which requires a Type 3 certificate of conformity from a notified body and lists SASO NFPA 20 in its annex; certificates run through SABER. A typical path:
- Agree the design basis with the consultant: codes, editions, hazard and water source.
- Prepare the submittal listed above.
- Close every consultant comment in writing before ordering.
- Follow the project’s Civil Defense approval route, as our Civil Defense approval guide explains, or the High Commission for Industrial Security route for facilities it supervises.
- Install, flush and hydrotest, then run the field acceptance test in our fire pump acceptance testing guide.
- Keep the records for facility licensing and NFPA 25 testing.
Common mistakes and what drives cost
- Sizing from a catalog rating, or a duty point at the end of the curve.
- Ignoring churn plus static suction pressure in tall buildings or with pressurized supplies.
- Suction calculated on a full tank, or a horizontal pump drawing from a source below it.
- Catalog logos instead of the listing record for the exact model.
- No room to pull the rotating assembly, or controller signals not wired to the fire alarm panel.
Cost follows the pump type and size, the driver and what it brings (generator and transfer switch, or fuel, exhaust and ventilation), the controller and starting method, room, tank and test works, and the listing route.
How AZEIDK helps
Through our firefighting system solutions, AZEIDK supports pump projects with engineering design and calculations, technical selection of systems and equipment and Civil Defense approval support within the agreed scope of work.
Brands within our supply scope include Jack Pump, specialized in stationary fire pumps, with VES end-suction, MSC split-case and VTP vertical turbine series; check each model’s UL listing or FM Approval in its datasheet. With 16+ years in the Saudi market, we review the selection and approval documents with you before supply.
FAQ
How do I calculate fire pump flow and pressure?
Flow comes from the hydraulic calculations of the system with the highest demand, such as the sprinkler design area plus hose allowance, or the standpipe demand. The pump adds the difference between the pressure needed at its discharge, including losses, and the minimum suction pressure at the lowest tank level.
What is the difference between split-case, end-suction and vertical turbine fire pumps?
A split-case pump is rugged and suits larger flows but needs more space. An end-suction pump is smaller and cheaper and suits smaller flows. A vertical turbine pump serves water sources below the pump, such as wells and underground tanks, and is usually lifted out for service.
Does a fire pump need to be UL Listed or FM Approved?
NFPA 20 requires the pump to be listed by an organization acceptable to the AHJ; specifications and insurers usually ask for a UL 448 listing or an FM Approval. FM has a standard per pump type, and FM 1311 covers split-case pumps only. Check the model in the official directory.
Can the system demand exceed the pump’s rated flow?
Yes, up to 150% of rated flow, because the pump must deliver that flow at no less than 65% of rated pressure. It is still recommended to keep the duty point mid-curve, below about 140%, leaving a margin for suction losses and aging.
What documents are needed to approve a fire pump in Saudi Arabia?
Usually the data sheet and curve, listing evidence for the exact model, driver and controller data, calculations and pump room drawings. The pump needs a certificate of conformity under the Technical Regulation for Fire Control Materials and Equipment, and the project follows its Civil Defense approval route.
Selecting a fire pump or preparing its submittal? Send us the hydraulic calculations, tank details and specification, and our engineers will review the pump selection and approval documents with you. Contact the AZEIDK team
