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Underground Fire Hydrant Manufacturer

Underground fire hydrant is a type of fire hydrant that is installed below ground level, typically for use in areas where above-ground hydrants may be impractical or vulnerable to damage. It consists of a below-ground valve system that is activated by opening a cover at the surface. These hydrants are often used in urban environments, especially in cold climates, to avoid freezing or interference with traffic.

Underground fire hydrant remains hidden beneath the surface, with only a cover visible.Firefighters open the cover to access the valve, and then a special tool is used to operate the valve to release water.It is ideal for places with space constraints, cold climates, or where aesthetic considerations are important, such as city streets, parking lots, or airport runways.These hydrants are designed to provide easy and reliable access to water during emergencies while minimizing their exposure to damage or freezing.

Judberd can offer below underground fire hydrants.We also can design according to your requirement.

Underground Fire Hydrants Series No. UFH001

Underground Fire Hydrants Series No. UFH002

Underground Fire Hydrants Series No. UFH003

Underground Fire Hydrants Series No. UFH004

Underground Fire Hydrants Series No. UFH005

FEATURE

Various Flange Drilling Designs

Flange can be drilled according to EN1092-2 /ISO7005-2 as the left photo

Flange can be multi drilled according to EN1092-2 /ISO7005-2 which is marked in black circle and BS10 Table D/Table E which is marked in white circle as the right photo

Auto drainage hole

The copper plug designed by Judberd is essentially a small check valve. When the Underground Fire Hydrant is in operation and has internal pressure, the steel ball, under pressure, compresses the spring to block the drainage hole. When the underground fire hydrant is not in use and has no internal pressure, the steel ball, assisted by the spring, opens the drainage hole to release water from the valve body. This prevents freezing inside the valve body, avoiding damage to internal components.

Various Outlet Design

The outlet material can be brass, bronze , stainless steel etc ,the thread can be 2 1/2“ male London round outlet or customized

Detachable Underground Fire Hydrants Feature

The Detachable underground fire hydrant consists of an isolation valve (isolate valve can be a gate valve, butterfly valve, ball valve or globe valve that can be used as a cut-off valve), a duck foot bend and a threaded outlet (the material of the threaded outlet can be brass, bronze , stainless steel or other materials), these three parts are connected through flanges, and each component can be disassembled and used independently.

Structure and Working Principle of Underground Fire Hydrant

Underground fire hydrant mainly consists of a ground cover, an operating mechanism (valve stem), a valve body, and an outlet connection (typically for connecting a fire hose).

During operation, firefighters open the ground cover and use a special tool (such as a hydrant wrench) to operate the valve and release water, then connect a fire hose to draw water.

When not in use, the valve remains closed, and the interior stays filled with air to prevent freezing or water accumulation.

Difference Between Underground and Above-Ground Fire Hydrants

Underground fire hydrants are better suited for cold climates or areas with limited space. They are less prone to damage and do not obstruct traffic.

Above-ground fire hydrants are easier to locate and operate quickly during emergencies but are more vulnerable to damage from impacts, freezing, or environmental exposure.

Applications of Underground Fire Hydrants

Underground fire hydrants are commonly used in city streets, public squares, airport runways, commercial areas, and regions with cold climates.

They are ideal for environments where a concealed installation is required or where protection against freezing is necessary.

How to Select the Right Underground Fire Hydrant？

Choosing the right underground fire hydrant is essential to ensure reliable performance in firefighting systems. Here’s a simple step-by-step guide to help you select the appropriate model:

1, Confirm the Required Working Pressure (e.g., PN10, PN16) PN10 (10 bar) is suitable for standard water supply systems with moderate pressure.PN16 (16 bar) is preferred for higher pressure systems or where additional safety margins are needed.Always check the system’s operating pressure before selecting the hydrant to avoid mismatch.

2,Choose the Right Connection Type Flanged Connection:Commonly used and offers a strong, secure joint.Suitable for fixed installations where durability is a priority.

Quick Coupling (Quick Connect):Allows faster and easier installation or removal.Ideal for systems that may require frequent maintenance or replacement.Verify the type of connection used in your existing pipeline system.

3,Select the Proper Material Ductile Iron Body:Strong, impact-resistant, and ideal for heavy-duty use.Offers excellent durability in various environments.

Copper Alloy Parts:Corrosion-resistant, especially for critical components like valve seats and stems.Extends the lifespan of the hydrant in harsh water or soil conditions.For general city infrastructure, ductile iron with copper alloy internals is a safe and widely accepted choice.

4, Decide on the Anti-Corrosion Coating Epoxy Powder Coating:Provides a thick, smooth protective layer.Excellent for corrosion resistance in fresh water and urban environments.

Hot-Dip Galvanizing:Best for extreme environments like coastal areas or places with highly corrosive soils.Adds a thick zinc layer to protect against rust.Choose epoxy coating for regular conditions; choose hot-dip galvanizing for highly corrosive environments.

5,Match the Pipe Size and Fire Hose Connection Pipe Size:Ensure the hydrant matches the pipeline diameter, usually DN80 or DN100.

Outlet Size:The fire hose connection must also match the local fire service standards, typically DN80 or DN100 outlet.Double-check both the pipe and hose specifications before finalizing your choice to ensure compatibility.

Installation and Maintenance Requirements for Underground Fire Hydrants

1, Installation Depth The underground fire hydrant must be installed below the local frost line to prevent freezing during cold weather.The exact installation depth should be determined based on the region’s climate data, ensuring that the entire valve assembly remains protected from freezing temperatures.In colder climates, deeper installation is necessary. Always consult local standards or engineering guidelines to confirm the required depth.

2,Drainage System A proper drainage system must be installed beneath or around the hydrant to ensure that water can be automatically drained after use.This prevents standing water inside the hydrant, which could freeze and damage internal components.Common drainage methods include installing a gravel sump or a perforated pipe system below the hydrant to facilitate quick water discharge.Regularly check the drainage system during inspections to ensure it remains unblocked and effective.

3,Regular Inspection and Maintenance Periodically operate the hydrant (open and close it fully) to ensure the valve moves smoothly without sticking or excessive resistance. Inspect the internal seals and gaskets for any signs of wear, cracking, or leakage. Good sealing is critical to maintain system pressure and prevent water leakage. Ensure that the ground cover is intact, easy to open, and free from obstruction. It must remain accessible at all times for emergency use. If necessary, flush the hydrant to remove any accumulated debris, sand, or silt that may obstruct operation.Inspect visible parts (such as the valve stem, bolts, and fittings) for signs of corrosion or coating damage. Reapply protective coatings as needed.Establish a regular inspection schedule (e.g., semi-annually or annually) and keep records of maintenance activities for safety audits and insurance compliance.

How to Install Underground Fire Hydrant?

The height from the underground hydrant outlet to the ground should be 1.10m, and the sign should be prominently displayed.

The location sign of the outdoor fire hydrant should be clear, and the position of the hydrant outlet should be easily accessible.

Prevent falling objects above it.

The installation dimensions for outdoor fire hydrants and fire pump connectors should comply with design requirements, allowing a deviation of ±20mm in hydrant outlet installation height.

For underground fire hydrants, the distance between the top outlet and the bottom surface of the fire well cover should not exceed 400mm.

There should be sufficient operating space inside the well, along with a ladder.

In cold regions, measures should be taken to prevent freezing inside the well.

You need to assemble the inlet flange with other pipeline component flange together, and connect the fire hose to the outlet thread .There should be no leakage under pressure.