The NFPA requires certain information.
Contractors installing new sprinkler systems outfit them with hydraulic data signs that contain at least the minimum standard information as required by the NFPA. That information is as follows:
- Hydraulic Remote Area(s)
- Discharge Densities
- System Demand
- Hose Stream Allowance
- Occupancy Classification
- Name of Installation Contractor(s)
Hydraulic Remote Area(s)
Contractors identify parts of a building where the demand for water is considerably higher than in the rest of the structure (i.e. locations that present the most significant challenge for a hydraulic system to reach). Regions of a building that have comparatively low exposure or poor proximity to a sprinkler have been defined as “remote areas” and they need more water at a higher discharge pressure in order to be satisfactorily covered by a sprinkler’s discharge in the vent of a fire.
The entire sprinkler system will have been specifically designed to supply these hydraulic “remote areas” with an increased water supply and increased water pressure, but these remote regions of the building must be properly identified on the hydraulic data sign.
Discharge Densities
After remote areas are determined, installation contractors must allocate a specified amount of water for use in that hard-to-reach region. The density of the water discharge required to reach a remote area is notated in gallons per minute (gpm) and the required water pressure is notated in pounds per square inch (psi).
For this field, an inspector will handwrite the (gpm) and (psi) values revealed during inspection on the hydraulic data sign. These values will then be compared to the system demand values to determine if something in the system is amiss.
System Demand
The base of the system component called the riser generates the water pressure for the entire hydraulic system. When a fire sprinkler is triggered by smoke or heat, it’s the riser that pumps the water from that base for distribution through a building’s pipes. “System demand” refers to the water discharge and water pressure required to extinguish a fire in any part of the building. In other words, these are the values required for a sprinkler system’s operation.
A system’s demand can be used to gauge the current performance of the system during an inspection. If an inspection reveals that the the current amounts of discharge and pressure don’t meet the required gpm and psi thresholds displayed on the hydraulic data sign, then the inspector will be able to recognize that something is wrong and out of place.
Hose Stream Allowance
As a supplement to fire sprinklers, firefighters who arrive to fight any fire that breaks out can attach hoses to the hydraulic system and pull water from the same source as the sprinklers do.
A system is designed to contend for this possibility and the amount of water to be allocated for fire hoses can be pre-determined. The relevant discharge allowance values (i.e. how much water hoses can disperse from the system) are to be listed on the hydraulic data sign and notated in gpm.
Occupancy Classification
All buildings have different dimensions and specialized needs, so sprinkler system designers have to build different types of sprinkler systems to accommodate various types of facilities. For example, larger buildings will naturally require systems with higher water capacities and laboratories will need a specialized sprinkler system to contend with the flammable liquids stored there.
The size of a structure and the specialized nature of its interior environment determine the classification of the sprinkler system needed to protect it. In other words, systems are classified according to the system’s hydraulic base size (the size of the machinery powering the system) and the system configurations that are possible given the building’s shape and specific needs.
These “occupancy classifications” are important pieces of information for inspectors and are listed as follows:
- Group A: Entertainment venues, worship sanctuaries, restaurants (‘average’ places that regularly house groups of fifty or more customers/attendees)
- Group B: Banks, insurance agencies, government agencies, medical offices
- Group E: Educational centers, schools, daycares
- Group F: High-hazard facilities, factories
- Group I: Hospitals, nursing homes, prisons
For example, when an inspector arrives at a prison, he would see on the hydraulic data sign attached above a valve that he was operating in a facility with ‘I-Occupancy.’
Name of Installation Contractor(s)
The hydraulic data sign must also contain the name of the contractors and company that first installed the automatic sprinkler system.
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It’s important to note that inspectors must update the signs’ information should they make any adjustments to the system during their inspection or notice any changes since the last time the information was inscribed on the sign.