Outdoor Fire Hydrants and Fire Protection Systems: What the ISU Approval Requires
How to size an outdoor fire suppression system, why backup and pumping capabilities are needed, and when approval is withheld.
The outdoor fire protection system is the part of the project that is most often left until last and that most frequently delays final acceptance. The reason is simple: it doesn’t depend solely on you, but on what the public utility network can deliver to your connection point.
What to Check First
The fire safety plan specifies the flow rate and operating time required for the facility, based on its use, area, and risk. These determine the volume of the water supply and the number of outdoor fire hydrants.
The next step is to ask the water utility: what flow rate and pressure can they guarantee at the connection point? Almost always, the answer falls short of what’s needed—public water systems are designed for domestic use, not for firefighting. This determines the need for an on-site water supply and a pump station.
Components of a Complete System
- the fire protection tank, with a volume based on the scenario and an intangible reserve
- the water supply system: a pumping station with an active pump, a backup pump, and a pilot pump
- backup power supply, so that the pumping system continues to operate even during a power outage
- the outdoor looped network and above-ground or underground fire hydrants
- the supply connection for fire trucks
The outdoor network should be designed as a loop whenever possible: a branched network creates dead ends, and a failure renders everything downstream inoperative.
Why Applications Are Rejected
The most common reasons for the documentation being rejected are hydrants located at distances that do not cover the entire building, a reserve capacity that is too small relative to the theoretical operating time, and the lack of operational tests upon commissioning.
The test is performed using a flow meter at the most disadvantaged hydrant—the one that is farthest away and highest up. If the required flow rate and pressure are achieved there, the system is deemed satisfactory throughout. We install outdoor fire protection systems along with the associated tanks and pump stations, and we hand over the project after conducting the tests in the presence of the inspector.
Services covered in this article
We deliver the work described above in Brașov and across the county.