Underground Fire Hydrant
The design and installation of hydrant systems should be closely correlated with all other services being provided in the building, and ducts may be shared. The water supply to hydrants should be kept entirely independent from other water supplies including those for other fire-fighting systems.
Hydrant systems should be afforded all possible protection against frost.
Provision & Siting
When they are considered to be necessary, private fire hydrants should be provided within the confines of the site after consultation with the local water and fire authorities. Their installation should conform generally to this British Standard and also to any specific requirements of these authorities or the insurance company.
Fire hydrants should be positioned in such a way that the parking, loading and unloading of vehicles is unlikely to obstruct them, and in choosing locations for them regard should be paid to the availability of statutory hydrants in public thoroughfares nearby.
Where fire hydrants are to be installed, they should be included as part of a ring fire main system and be positioned not more than 90 m from an entry to any building on the site and not more than 90 m apart.
Siting of underground fire hydrants in roadways should be avoided but where necessary the frame and over should be in accordance with BS 750 and capable of bearing the heaviest vehicle anticipated to use the roadway.
Underground fire hydrants should be in accordance with BS 750 and BS EN 14339. Pillar hydrants should be in accordance with BS EN 14384. Where pillar hydrants are installed, care should be taken to protect them from mechanical damage and from damage by frost.
Ring Main Supply
Where a number of fire hydrants or wet fire mains are required because of the area of the premises to be covered, the mains supplying these systems should be in the form of a ring main to form a complete circuit of the site. It is advisable for water to be supplied to the ring at more than one position, preferably from supplies obtained from different sources.
Isolating valves should be incorporated in the system so that sections of the ring main can be isolated to enable repairs to be carried out. Branches to town’s mains should also have an isolating valve and a non-return valve to suit the water undertaker’s requirement.
Tests on Private Fire Hydrants
Inspection of and, where practicable, a wet test of private underground fire hydrants should be made in conjunction with the fire authority and the owner or occupier of the premises or their representative. Where such hydrants are supplied from mains, arrangements should also be made with the water undertaking before tests are carried out.
During these inspections and tests the condition of the following should be checked and noted for remedial action if necessary:
- Surface paving round edges of frames
- Depth of outlet below the frame, which should be no more than 300 mm below ground level
- Method of indication by means of hydrant indicator plate or sticker
The test should include flushing out the outlet and checking the outlet connection. The flow and pressure at the outlet should also be measured and noted.
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.