Underground Fire Hydrants

Installing an underground fire hydrant system requires careful planning, coordination and adherence to regulatory requirements to ensure effective fire protection capabilities. By following these basic steps and best practices, property owners, facility managers and fire protection professionals can install reliable and robust fire hydrant systems to protect lives and property from the devastating impact of fire.

Underground Fire Hydrant Benefits

Fire hydrants are based on a gate valve design with a fully vulcanized wedge, fixed wedge nut and triple safety stem seal. They feature:

Automatic Drain

The 8mm diameter drain opening is automatically closed above the full lift valve, so that no pressurized water can escape. This means that the drain opening closes before pressurized water can flow into the hydrant, and no pressurized water can escape. The valve disc in a single-close underground fire hydrant is asymmetrically designed to speed up the drawdown and discharge of water. This also reduces the number of cycles from the closed position to the stop.

Corrosion protection

Double-sealing underground fire hydrants are equipped with threaded holes for all threaded connections. This refers to the connections between the claw, the end cap and the upper cylinder as well as between the upper cylinder and the ball chamber. There are no open threaded steps, which avoids contamination and corrosion. Furthermore, the main sealing ring of the ball seal is vulcanized with EPDM for improved corrosion protection.

Improvements

In order to facilitate installation and ensure the best possible handling comfort, the weight of the fire hydrants has been optimized. The valve cone is completely vulcanized with polyurethane (PUR), the high quality of this synthetic rubber ensures perfect tightness due to its unique memory effect. The double-sealing of the stem consists of a scraper and a brass bushing as a plain bearing with three O-rings.

Installation of underground fire hydrants

The design and installation of fire hydrant systems must be closely linked to all other services provided in the building. Care must be taken that the water supply to the fire hydrants remains completely independent of other water supplies, including those of other fire-fighting systems. Fire hydrant systems must be provided with all possible protection against frost.

Video showing the parts of an underground fire hydrant

Equipment and location

Where deemed necessary, fire hydrants should be provided within the site boundaries after consultation with the local water and fire authorities. Their installation should generally comply with international standards and also with any specific requirements of these authorities or the insurance company.

Fire hydrants should be located in such a way that they are unlikely to be obstructed by parking and loading and unloading of vehicles, and when selecting their locations, consideration should be given to the availability of legal fire hydrants on nearby public streets.

If fire hydrants are installed, they should form part of the main fire circuit system and should be located no closer than 90 metres from the entrance to any building on the site and no closer than 90 metres.

They should preferably be located next to roads or suitable hard facilities for fire and rescue services. To ensure that they remain usable during a fire, they should be located with due regard to the impact that falling debris and other potential fire events may have on the continued usability of the site, and should be at least 6 metres away from a building or other hazard.

Underground fire hydrants should be avoided in roads, but where necessary the frame and top should be capable of supporting the heaviest vehicle expected to be used on the road.

In the case of vertical fire hydrants, care should be taken to protect them from mechanical damage and frost damage.

Loop Main Supply

Where a number of fire hydrants or wet fire hydrants are required due to the area of the building to be covered, the mains supplying these systems should be looped to form a complete circuit of the site. It is advisable to supply the looped pipe with water in more than one location, preferably from supplies obtained from different sources. Isolation valves should be incorporated into the system so that sections of the looped pipe can be isolated to enable repairs to be made. Branches leading to the city mains should also have an isolation valve and a check valve to suit the requirements of the water company.

Tests on private fire hydrants

A wet inspection and test of private fire hydrants underground should be carried out, where possible, in conjunction with the fire authority and the owner or occupier of the building or their representative. Where such hydrants are supplied from the mains, arrangements should also be made with the water company before carrying out the tests.

During these inspections and tests, the condition of the following should be checked and recorded. So that corrective action can be taken if necessary:

Excavations
Frames
Coverings
Surface paving around the edges of the frames
The depth of the outlet below the frame, which should not exceed 300 mm below ground level
Method of indication by means of an outlet indicator plate or label
The test should include flushing the outlet and checking the connection of the outlet. The flow and pressure at the outlet should also be measured and recorded.
On completion of the test, the operation of the frost valve (where fitted) should be checked and the pit should be left empty and clean.

Advantages of installing an underground fire hydrant

Valves and fittings

Specially designed for highly congested urban areas, the underground fire hydrant is discreet and offers a high degree of security.

Ease of installation:

Independent casing that centers and moves according to the fire hydrant, regardless of the slope of the pavement
Adjustable flange at the duck foot bend level for easy adjustment
Integrated lifting rings

Resistance:

Any pressure on the casing is completely absorbed by the ground and not the equipment. The integrity and tightness of the connection with the pipeline is maintained.

Durability:

Merced cast iron casing with industrial coating for added durability.
Hinged casing that requires no special maintenance.
Epoxy coating on the fire hydrant body.
Same sealing system as vertical fire hydrants, i.e. mercedes cast iron check valve coated with EPDM with full automatic drain.
13% chromium stainless steel operating stem.

Flexibility:

Fire hydrants can remain operational during work on the pavement by raising the casing to the level of the new pavement.

How to Install a Fire Suppression System

Fire sprinkler system installation is a critical aspect of fire safety infrastructure in buildings, industrial facilities, and communities. These systems provide firefighters with a reliable source of water to efficiently fight fires. Proper installation is essential to ensure the system operates effectively during emergency situations. Here are the basic steps involved in installing a fire sprinkler system.

Initial Planning:

Conduct a thorough assessment of the property or area to determine the ideal locations for fire sprinkler systems. Consider factors such as building layout, access to water sources, and fire department requirements.
Obtain necessary permits and approvals from local authorities and regulatory agencies before beginning installation.

Design and Planning:

Develop a detailed design and layout plan for the fire sprinkler system, including the location of fire sprinklers, underground pipes, valves, and main water lines.
Ensure compliance with relevant codes, standards, and regulations governing fire sprinkler installation, and local building codes.

Water Supply Connection:

Select a suitable water supply source, such as a municipal water main or a dedicated fire protection water tank.
Install a fire department connection to facilitate the connection between the fire hydrant system and the water supply source. The fire department connection typically includes valves, pipes, and fittings.

Excavation and Installation of Underground Pipes:

Dig trenches to place underground pipes to connect the fire hydrants to the water supply source.
Install wrought iron or PVC pipes according to design specifications and local codes, ensuring proper alignment and support.

Installing Fire Nozzles:

Place fire hydrants in designated locations along streets, parking lots, or perimeters of buildings, ensuring that they are easily accessible to firefighters.
Drill holes for the fire hydrant bases and secure them using concrete casings or fire hydrant mounting pads.
Connect fire hydrants to the underground piping network using appropriate fittings and valves.

Valve Installation and Testing:

Install isolation valves, gate valves, and other necessary control devices at strategic points along the piping network to control water flow and isolate sections for maintenance.
Perform pressure tests to ensure the integrity of the piping system and verify proper operation of valves and fittings.

Backfill and Resurface:

Back excavated trenches with appropriate materials, and compact them to prevent settling or damage to the pipes.
Restore surface areas, such as sidewalks, roads, or landscaping, to their original condition or in accordance with local regulations and aesthetic considerations.

Signs and Markings:

Install visible signs and markings to indicate the presence and location of fire hydrants. Ensuring they are easily identifiable by emergency responders and maintenance personnel.
Paint fire hydrants and markings according to standard color codes to indicate water flow capacity and other relevant information.

Inspection and Operation:

Schedule a final inspection with local authorities or fire department officials to ensure compliance with regulatory requirements and confirm proper installation and operation of the fire hydrant system.
Operate the system and perform flow tests to verify water flow rates and pressure levels at each hydrant.

Ongoing Maintenance and Monitoring:

Establish a regular maintenance schedule to inspect and maintain the fire hydrant system, including flushing hydrants, lubricating valves, and repairing any leaks or damage.
Keep accurate records of maintenance activities, inspections, and tests to ensure the system remains in optimal condition and complies with regulatory standards.