Fire Hydrant System

A fire hydrant system is a critical component of fire protection infrastructure, designed to provide fire-fighters with immediate and reliable access to water for extinguishing fires. It consists of a network that connects to the main water supply via pipes and incorporates several essential elements to ensure effective firefighting operation.

Key Components

• Fire Hydrants: Outlet points—usually above ground—where firefighters attach hoses to draw water from a pressurized supply.
• Pipes: Durable underground pipelines, typically made of steel or ductile iron, distribute water throughout a facility or neighborhood.
• Valves: These control water flow into and through the hydrant system, allowing sections to be isolated for maintenance or quickly activated during emergencies.
• Pumps: Systems often include a combination of jockey pumps (to maintain pressure), main electric pumps, and standby diesel pumps for redundancy if the main pump fails.
• Hose Reels and Couplings: Enable rapid connection and deployment of fire hoses, linking hydrants to nozzles used to direct water onto the fire.
• Pressure Gauges: Allow monitoring of water pressure in the system so proper flow rates are maintained.
• Fire Brigade Connections: These inlets allow firefighters to supplement the water supply using external fire engines if necessary.

How It Works

• The system is typically kept pressurized at all times by the jockey pump. When a hydrant is opened during a fire, any significant drop in pressure triggers the main pump to start automatically and deliver high volumes of water. If electrical power fails, a diesel-driven pump takes over to ensure uninterrupted water delivery.
• Firefighters open hydrants with a dedicated wrench, connect hoses, and the pressurized water can be immediately directed towards controlling or extinguishing a fire.
• Hydrants are generally designed to deliver a minimum flow rate—most often at least 250 gallons (950 liters) per minute.

Types of Fire Hydrant Systems

• Wet Barrel Hydrant remains filled with water; allows instant access
• Dry Barrel Interior remains dry until in use; designed to prevent freezing
• Internal Installed inside buildings; often include landing valves and fixed hose reels.

Color Codes

Hydrant colors often indicate water flow capacity

• Blue 1,500 GPM or more (high capacity)
• Green 1,000–1,499 GPM
• Orange 500–999 GPM
• Purple 500–999 GPM