e. Ringed fire hydrant pipes

For a building that is required to have an island site fire engine accessway the fire hydrant pipe shall be a ring system. Isolation valves shall be provided on the fire hydrant ring such that on any section of ring, not more than one fire hydrant can be isolated when required for maintenance without affecting the water supply (both designed pressure and flow) to the other fire hydrants on the ring.

f. Valve locking device

A locking device shall be provided to lock the valves in open position during normal operation. Underground valves shall be kept in an open position at all times.

a. Private fire hydrant at or below reduced level 125m

(1) Private fire hydrants installed at reduced level 125m and below can receive direct supply from public water mains provided the flow and pressure from the public water mains meet the fire hydrant requirements as shown in Table 4.4A, or the following requirements are complied with:

(a) the AFA of the largest compartment shall not exceed 1000m² for PG III, IV, V & VII and not exceed 500m² for PG VI & VIII buildings. No AFA limit for covered car park in PG II, III, IV, V & VII buildings;

(b) the nominal bore of the fire hydrant pipe and the bulk water meter shall not be less than 150mm in diameter; and

(c) the running pressure/flow at the hydraulically most unfavourable fire hydrant of the private fire hydrant system shall comply with the following: 

(i) running pressure >= 0.9 x (running pressure of the nearest public fire hydrant – pressure drop across the bulk water metre); and 

(ii) flow rate >= 0.9 x water flow of the nearest public fire hydrant or >= total flow demand (as required in Table 4.4A) of the private fire hydrant system, provided the running pressure at the most remote private fire hydrant is greater than 2 bars. 

Note: 
In calculating the frictional loss for the private fire hydrant system, the design flow rates shown in Table 4.4A shall be used. The pressure drop across bulk water metre shall not be more than 1 bar.

(2) If the requirements stipulated in Cl.4.4.2a.(1) cannot be met, a storage tank of sufficient capacity meeting the flow rate and duration as specified in Table 4.4A with the requisite pumping facilities shall be provided.

All fire hydrant mains which pass through a building shall have its full length within the building protected with fire resistance construction complying with Cl.3.8.7b.of at least the same fire resistance as the element of structure, provided all of the following requirements are complied with:

a. The fire hydrant mains shall be located in common circulation areas, such as car parking spaces (except spaces used for mechanical car parking) and driveways, i.e. they shall not pass through private or confined spaces.

b.  No services other than sprinkler pipe(s) shall be located above or crossing over the fire hydrant mains. Where services need to cross-over the hydrant mains, the following conditions shall be complied with:

(1) the services shall only cross over the fire hydrants mains perpendicularly;

(2) the tensile stress of the supports for the services shall not exceed 10N/mm²; and

(3) the services shall be adequately protected by the building’s sprinkler system.

c. The fire hydrant mains shall be located away from explosion risk areas.

d. The protective enclosure to the fire hydrant mains shall be labelled with the words “FIRE HYDRANT MAIN” of minimum 50mm height at suitable intervals.

Diagram 4.2.2e.: Turning facilities for firefighting appliances