NY Fire Sprinkler key terms

A heat-activated device connected to a piping network that opens at a preset temperature and discharges water over a defined area to control or extinguish a fire.

A number expressing the discharge coefficient of a sprinkler or nozzle, relating water flow in gallons per minute to the square root of supply pressure in psi.

The nominal activation temperature marked on a sprinkler's fusible element, selected to exceed expected ambient ceiling temperatures while opening early enough to control a fire.

A sprinkler with a low response time index, typically under 50, whose fast-operating element allows use of smaller design areas and longer spacing in many occupancies.

A measure of how rapidly a sprinkler's heat-responsive element reacts to a growing fire, expressed as response time index and classified as quick, standard, or special response.

The hydraulically most demanding remote area of sprinkler operation assumed to be flowing simultaneously when calculating system demand; its size depends on occupancy hazard and sprinkler type.

The minimum water application rate, in gallons per minute per square foot, that a sprinkler system must deliver over the design area for a given hazard classification.

The grouping of occupancies by fire severity and amount of combustibles, such as light, ordinary, or extra hazard, which sets density, spacing, and design area requirements.

A hazard category for occupancies with moderate to substantial combustible loading and moderate dust or stock, such as certain mercantile and industrial spaces, requiring higher density than light hazard.

A sprinkler system in which automatic supply lines and piping are kept filled with pressurized water at all times so that a opened sprinkler discharges immediately.

A sprinkler system in which piping above the control valve is filled with pressurized air or nitrogen; a sprinkler opening releases the air, allowing water to enter and flow.

A system where the piping may be dry and water is admitted only after a fire detection signal, often with a second interlock, to protect areas where accidental discharge is costly.

A system using open sprinklers or nozzles in which a single detector or manual release opens a deluge valve, discharging water simultaneously from all connected heads.

A clapper-type valve that holds back water supply using air pressure above it and opens when a sprinkler release drops the air pressure, admitting water to the system.

A quick-opening valve that, when actuated by a detection or release device, admits water to a deluge or preaction system's open piping network.

The mathematical method of summing friction losses, elevation changes, and fitting losses through piping to prove that supply pressure and flow satisfy the required demand.

The pressure remaining at a hydrant or test outlet while water flows at a measured rate, used with static pressure to estimate the available water supply.

The pressure measured at a point in a water supply system when no water is flowing, reflecting elevation head and the supply's resting pressure.

A test that opens the main drain fully and records static and flowing pressure at the gauge, verifying that the water supply and control valves are in proper condition.

A test of a dry pipe valve in which the system air pressure is bled to simulate a sprinkler operation, confirming the valve opens within the required time.

The practice of keeping a dry or preaction system's air or nitrogen pressure within specified limits using a compressor and regulator to prevent valve tripping and water entry.

The maximum permitted distance between adjacent sprinklers or between a sprinkler and a wall or obstruction, governed by hazard and sprinkler listing.

The floor area protected by a single sprinkler, determined by its spacing and the required density for the occupancy hazard.

A structural or architectural element such as a beam, duct, or soffit that can block sprinkler spray, requiring added sprinklers or increased clearance beneath it.

The component of a sprinkler that breaks up the water jet into a spray pattern; its distance below the ceiling and orientation affect coverage.

A sprinkler designed to hang below the piping with its deflector facing downward, producing a hemispherical spray pattern below the ceiling.

A sprinkler mounted above the piping with its deflector facing upward, throwing water in a pattern that then falls from the ceiling.

A sprinkler with a specialized deflector that discharges water outward from a wall, used where ceiling piping is impractical and coverage limits are tighter.

A fixed piping system with hose connections at various levels that delivers water for manual firefighting, classified by whether it supplies water automatically and at what pressure.

A standpipe system with 2.5-inch hose connections intended for use by fire department personnel, typically required in tall or large buildings to reduce hose lengths.

A standpipe system with 1.5-inch hose stations for occupant use on a limited basis, often combined with Class I outlets in a combined system.

An exterior connection with inlets that lets responding pumpers supplement a building's water supply and pressure for sprinklers and standpipes.

A standpipe system that relies entirely on fire department pumpers for water and pressure, since it has no permanent automatic supply.

A standpipe system connected to a permanent water supply capable of delivering the required pressure and flow without fire department pumping.

A device that lowers high system pressure at an outlet to a level safe for hose and nozzle use, required where static pressure at a hose connection exceeds limits.

A pump installed to boost water pressure and flow when the public supply cannot meet the sprinkler or standpipe demand, controlled by automatic starting devices.

A small pressure-maintenance pump that keeps a fire protection system's piping pressurized and prevents the main fire pump from starting during minor leaks.

A valve, usually at the end of the most remote branch, that opens to simulate a single sprinkler and confirm water reaches the far end of the system.

A device that senses water movement in a pipe and transmits an alarm signal, typically required on each sprinkler system riser and monitored by the fire alarm panel.

A supervisory device that signals the fire alarm system whenever a control valve is moved from its fully open position, ensuring prompt notification of closure.