Fire System Pressurization Jockey Pump
Everything about jockey pumps: role in fire protection systems, sizing by design practice (~1% of main pump flow), setpoints and NFPA 20 / NBR 16704 standards.
TL;DR
The jockey pump is the automatic pressurizer of the NFPA 20 fire system — it keeps static network pressure between two narrow setpoints so the main fire pump only starts on a real fire demand.
Sizing by established design practice: replace the normal network leakage without starting the main pump — typically ~1% of the main pump flow (500 GPM main → ~5 GPM jockey).
Shutoff pressure 5-10 psi above the main pump stop point — prevents the fire pump from short-cycling and the assembly from premature wear.
Typical construction: vertical multi-stage centrifugal in stainless 304/316 — high pressure at low flow — installed in parallel with the main pump.
Standards: NFPA 20 (annex A.4.27) and ABNT NBR 16704 address network pressure maintenance — a function fulfilled, in practice, by the jockey pump. FB Bombas supplies the jockey integrated into the FBFS skid, factory pre-assembled, aligned and tested.
Updated
What is a jockey pump and what is it for?
A jockey pump serves to maintain pressure in the fire-fighting network: it is the automatic pressurizer that compensates for small leaks in joints, valves and sprinklers between two setpoints. Its function is to prevent the main pump from starting on pressure drops. Standards: NFPA 20 and NBR 16704.
How to size a jockey pump?
The jockey pump is sized to replace the normal network leakage without starting the main pump — by established design practice, approximately 1% of the main pump flow. Example: a 500 GPM (113 m³/h) main pump → a ~5 GPM (1.1 m³/h) jockey. The jockey stop pressure should be 5 to 10 psi above the main pump stop pressure.
Difference between jockey and main fire pump?
The main pump provides flow and pressure for fire-fighting (hundreds of m³/h). The jockey is much smaller (typically ~1% of main flow) and maintains static pressure when there is no fire. The jockey operates frequently in short cycles of a few minutes. The main pump only operates in real emergencies, when there is significant water demand.
Why can't the jockey pump be eliminated?
Without a jockey, any microscopic leak in the network (normal in systems with hundreds of joints) would cause pressure drops and repetitive main pump activation. This premature wear compromises the main pump's lifespan — when a real fire occurs, it may fail. That is why designs per NFPA 20 and NBR 16704 provide for network pressure maintenance — a function fulfilled by the jockey pump.
How to set the jockey pump pressure switches?
The setting follows a pressure cascade: the jockey stop point is the highest setpoint in the system, the jockey start comes just below it, and the main fire pump start sits below the jockey start — so the jockey always restores network pressure before the main pump is called. NFPA 20 annex A.4.27 presents the calculation method based on the main pump churn pressure and the static suction pressure; in practice, the jockey stop point sits 5 to 10 psi above the main pump stop point.
How to Size
Technical criteria for correct specification
Flow Rate
Approximately 1% of main pump flow (design practice). Example: 500 GPM main pump = ~5 GPM jockey. Must be sufficient to compensate normal network leaks.
Pressure
Jockey shutoff pressure must be 5-10 psi (0.35-0.7 bar) above main pump shutoff pressure. This ensures the jockey maintains network pressure without interfering with main pump start logic.
Construction
Vertical multi-stage centrifugal in stainless steel AISI 304 or 316. Vertical configuration saves space on the skid. Multiple stages provide high pressure at low flow — exactly the jockey profile.
Motor
Electric, typically 1-5 hp. Direct start for motors up to 7.5 hp or soft-starter for higher powers. Three-phase 220/380/440V per installation. Thermal protection mandatory.
What Is a Jockey Pump?
Function, sizing and importance in fire systems
The jockey pump (or pressure maintenance pump) is a fire protection system component whose function is to maintain the static pressure of the network between two narrow setpoints, compensating for small leaks in joints, valves and sprinklers. It operates automatically and prevents the main pump from unnecessary starts.
Sized by established design practice to replace the normal network leakage — approximately 1% of the main pump flow —, the jockey is typically a vertical multi-stage centrifugal pump in stainless steel 304 or 316. FB Bombas supplies jockey pumps as an integrated part of fire fighting skids, with control panel, valves and instrumentation pre-configured.
Flow: ~1% of main pump (design practice)
Pressure: 5-10 psi above main pump shutoff
Construction: vertical multi-stage, SS 304/316
Operation: automatic via pressure setpoints
How Does a Jockey Pump Work?
Automatic pressure maintenance cycle
Leak Detection
Small leaks in joints, valves and sprinklers cause gradual pressure drop in the network. The pressure switch continuously monitors and detects when pressure reaches the lower setpoint (jockey start point).
Auto-Start
Upon reaching the lower setpoint, the control panel starts the jockey pump automatically. It restores network pressure with small flow (~1% of main), compensating the leak without activating the fire pump.
Auto-Stop
When pressure reaches the upper setpoint (typically 5-10 psi above main pump shutoff), the jockey stops. If pressure keeps dropping after jockey starts, it indicates real demand — the panel activates the main pump.
Jockey vs. Main Pump
Fundamental differences between the two devices
| Criteria | Jockey | Main Pump |
|---|---|---|
| Function | Maintain static pressure | Fire fighting |
| Flow rate | ~1% of main (1-5 GPM) | 100% (500-2500 GPM) |
| Pressure | 5-10 psi above main | System rated pressure |
| Operating frequency | Short daily cycles | Emergency only |
| Motor | 1-5 hp electric | 25-500 hp electric or diesel |
| Cost | 5-10% of total system | Main component |
Standards & Regulations
NFPA 20, NBR 16704 and installation requirements
Standard for the Installation of Stationary Pumps for Fire Protection. Defines requirements for jockey, main and standby pumps. Annex A.4.27 covers the pressure maintenance pump; sizing at ~1% of main flow is established design practice.
Brazilian standard for stationary fire protection pump installation. Aligned with NFPA 20, requires automatic pressure maintenance pump with setpoint logic and independent control panel.
Setpoint Logic
Lower setpoint (jockey start) > main pump start setpoint > standby start setpoint. Upper setpoint (jockey stop) must be 5-10 psi above main pump shutoff. Prevents conflict between pumps.
Control Panel
Dedicated or integrated panel. Must have run/fault indication, manual/auto mode and motor thermal protection. Independent power supply from normal grid (generator or dedicated circuit).
Frequently Asked Questions
What is a jockey pump?
A jockey pump (also called a pressure maintenance pump) is a component of a fire protection system whose function is to maintain the static pressure of the network between two narrow setpoints, compensating for small leaks at joints, valves, and sprinklers. It operates automatically and prevents the main fire pump from being activated unnecessarily.
How to size a jockey pump?
Consolidated design practice sizes the jockey pump at approximately 1% of main pump flow (NFPA 20 annex A.4.27 covers the pressure-maintenance pump; the criterion is replacing normal network leakage without starting the main pump). Example: if the main pump is rated at 500 GPM (113 m³/h), the jockey should be ~5 GPM (1.1 m³/h). The jockey pump pressure must be sufficient to reach the upper setpoint of the system — typically 5 to 10 psi above the main pump shutoff pressure.
What is the difference between a jockey pump and a main fire pump?
The main fire pump delivers the flow rate and pressure required for firefighting (hundreds of m³/h). The jockey pump is much smaller (1% of the main pump flow) and serves only to maintain static pressure when there is no fire. The jockey operates frequently in short cycles; the main pump operates only during an actual emergency.
What standards govern the jockey pump?
The main standards are NFPA 20 (Standard for the Installation of Stationary Pumps for Fire Protection) and NBR 16704 (Installation of stationary pumps for fire protection). Both require an automatic pressure maintenance pump with setpoint logic and an independent control panel.
Why can the jockey pump not be eliminated from the design?
Without the jockey pump, any microscopic leak in the network (normal in systems with hundreds of joints) would cause pressure drop and repetitive activation of the main fire pump, wearing it out prematurely. When a real fire occurs, the main pump may have compromised service life.
Can the jockey pump be a centrifugal pump?
Yes. The jockey pump is typically a vertical multistage centrifugal pump in stainless steel (304 or 316), sized for low flow rate and high pressure. FB Bombas supplies jockey pumps as an integrated part of their fire protection skids, with control panel, valves, and instrumentation already configured.
What does continuous jockey pump operation mean?
If the jockey pump runs continuously without shutting off, it indicates a significant leak in the system — larger than the jockey pump’s capacity to replenish. Immediate investigation is required: check for open sprinklers, leaking valves, or damaged joints. A normal jockey pump operates in short cycles of a few minutes.
How much does a fire jockey pump cost?
The cost of a jockey pump varies based on flow rate, pressure, material, and control panel configuration. FB Bombas supplies the complete system (jockey + main + diesel + panel) as an integrated skid. Request a quote with your project data for a specific quotation.
What is a jockey pump for?
The jockey pump keeps the fire-protection network pressurized, automatically replacing small leaks at joints, valves and sprinklers between two setpoints. Its function is to prevent the main pump from starting on a pressure drop. It is required by NFPA 20 and NBR 16704 in every fixed system.
What is the jockey pump for in a fire system?
In the fire system, the jockey maintains the static pressure of the hydrant and sprinkler network. It absorbs the micro-leaks that would otherwise start the main pump repeatedly — wearing out the set that must be intact in a real fire. It is sized, by design practice, at about 1% of the main pump flow.
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