printer friendly version

Hydrants, where, why and how many

Extracts from technical enquiries processed by the Association's library and deemed to be of interest to readers.

Enquiry:

Information on the provision of hydrants for single storey industrial premises and in particular the siting of hydrants and height above ground of pillar hydrants.

Reply:

SABS 0400 requires hydrants to be provided for:

* All buildings exceeding 12 m in height.

* High and moderate risk industrial premises of any height where the floor area exceeds 1000 m².

* Hydrants should be provided at the rate of not less than one per 1000 m² of floor area or part thereof.

* Hose and branchpipes should be provided if required by the local authority.

* Hydrants should comply with SABS 1128 Part 1.

* Water supplies should conform to the relevant sections of section WW of SABS 0400 - 1990.

FPAUK Fire Safety Data Sheet PE8 recommends external hydrants be positioned so that:

* They are not more than 150 m apart.

* There is one hydrant within 70 m of an entry to every building on the premises.

* Not less than 6 m from buildings to ensure they remain usable during a fire.

* Exits are not obstructed.

* The parking, loading and unloading of vehicles is unlikely to obstruct use of hydrants.

* They are immediately adjacent to roadways of hard standing suitable for fire appliances.

The NFPA Fire Protection Handbook recommends:

* Where hydrants are located on a private water system and hose lines are intended to be used directly from the hydrants, they should be so located as to keep hose lines short, preferably not over 75 m.

* For average conditions, hydrants are normally placed 12,2 m from the building to be protected. Where this is not possible, they are set where the chance of injury by falling walls is small and where fire-fighters are not likely to be driven away by smoke or heat.

I In crowded industrial yards, hydrants can usually be placed beside low buildings, near substantial stair towers or at corners formed by masonry walls that are not likely to fall.

* Hydrants located in areas subject to heavy traffic, need protection.

* Hydrants should be set plumb with outlets about 0,46 m above ground and 0,46 m above the floor in hose houses.

FPASA Bulletin 15 recommends:

* Hydrants spaced not more than 60 m apart must completely surround the property to be protected.

* Additional hydrants must be installed in such a way as to ensure that all parts of the property protected are within 90 m of a large bore nozzle attached to not more than 45 m of hose.

* Hydrant valves must match the local fire brigade hose couplings, but must in no case be smaller than 63,5 mm internal diameter.

* Each hydrant valve must be supplied with at least 45 m of approved hose of not less than 63,5 mm internal diameter, in two or more lengths of not less than 15 m each and with one branch pipe and nozzle 15,9 mm or larger in diameter. (Adjustable nozzles giving either spray or jets are recommended.)

Share this article:

Further reading: