SRS flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

K-factor

The discharge coefficient relating sprinkler flow to pressure by Q = K × √P. It gives flow in gpm at 1 psi and must not be altered by paint or modification.

Design density

The minimum water application rate in gpm/ft² applied over the hydraulically most remote operating area, and the basis for the sprinkler hydraulic calculation.

Glass bulb color code

Bulb color indicates temperature rating: orange 135°F, red 155°F, yellow 175°F, green 200°F, blue 286°F, purple 360°F, and black 440°F.

Remote area

The hydraulically most demanding area of sprinkler operation. Its size in square feet depends on hazard classification and the density/area curve selected for design.

Psi to feet of head

One psi equals 2.31 feet of water column, and one foot of water column equals 0.433 psi; these convert elevation differences into pressure loss in calculations.

Authority having jurisdiction

The organization, office, or individual responsible for approving equipment, installations, and procedures and for enforcing the adopted code edition in a given location.

NFPA 25 scope

It sets minimum inspection, testing, and maintenance frequencies for water-based fire protection systems after acceptance, covering valves, gauges, alarms, sprinklers, and pumps.

Code adoption by reference

Model codes take legal effect only when a jurisdiction adopts them; the adopted edition year and local amendments govern the project rather than the newest publication.

Annual main drain test

A flow test through the main drain that confirms the water supply and reveals closed or obstructed valves by comparing static and residual pressures against baseline readings.

Weekly fire pump churn

Fire pumps run weekly at no flow, at least 10 minutes for electric drive and 30 minutes for diesel drive, verifying automatic starting, pressure, and lubrication.

Ordinary hazard spacing limits

Standard spray sprinklers in ordinary hazard are spaced no more than 15 feet apart with no more than 130 square feet of protection area per sprinkler.

Deflector position

Standard spray pendent and upright deflectors are positioned 1 inch to 12 inches below the ceiling, measured to the deflector, unless the listing permits otherwise.

Three times rule

An obstruction is acceptable when the sprinkler is placed within three times the obstruction's depth below the deflector plane; otherwise additional sprinklers are required.

Water supply flow test

Hydrant flow data used for design must be no more than 12 months old and adjusted for seasonal and daily demand variations before use in calculations.

Pipe schedule method limits

Pipe schedule sizing applies only within limits on system area, occupancy, and pressure. Other systems require full hydraulic calculation to demonstrate adequate supply.

Hydrostatic test pressure

New sprinkler piping is tested at 200 psi for 2 hours, or at 50 psi above maximum working pressure where that working pressure exceeds 150 psi.

Impairment coordinator

The designated person who authorizes a system shutdown, notifies the AHJ and insurer, posts impairment tags, and establishes fire watch until protection is restored.

Underground main flushing

Buried mains are flushed before connection to building piping at a flow producing about 10 feet per second velocity, removing debris that could obstruct sprinklers.

Hot work permit

Written authorization required before cutting, welding, or grinding that specifies precautions, a fire watch during work, and monitoring for at least 30 minutes afterward.

Quarterly waterflow alarm test

Waterflow alarm devices and valve supervisory switches are tested quarterly by opening the inspector's test valve and confirming local alarm and remote signal reception.

Five-year internal inspection

Dry pipe and preaction piping, and piping in corrosive environments, is internally examined at 5-year intervals, with corrosion findings and corrective actions documented.

Spare sprinkler stock

At least 6 spare sprinklers for systems up to 300 sprinklers, 12 for 301 to 1000, and 24 above 1000, matching installed types and temperature ratings.

Gauge calibration interval

System gauges are replaced or recalibrated at 5-year intervals; any gauge with a broken lens or a reading off zero is replaced immediately.

ITM record retention

Inspection and test records are kept at least one year and made available to the AHJ; the system owner retains copies of all completed inspection and testing documentation.

Lockout tagout

An energy isolation procedure using locks and tags on pumps, valves, or electrical disconnects before maintenance, preventing unexpected energization or release of stored energy.

Fire watch during impairment

A person assigned to patrol the affected area with extinguishing equipment, maintaining a continuous watch while protection is out of service and until it is restored.

Freeze protection risk

Wet pipe systems in unheated spaces are protected by dry pipe, preaction, listed antifreeze, or heat; freezing ruptures pipe and disables protection, a major property risk.

Backflow prevention

An assembly that prevents reverse flow of nonpotable water into the potable supply, tested annually by a certified tester and reported to the water authority.

Working plans

Scaled drawings submitted for approval before installation, showing occupancy, sprinkler layout, pipe sizes, hydraulic calculations, and a bill of materials.

Hydraulic design placard

A sign at the riser stating design density, operating area, hose stream allowance, and duration so future modifications can be checked against the original design basis.

Material and test certificate

The contractor's signed record documenting flushing and hydrostatic testing, including system pressure, test duration, results, and the signature submitted to the AHJ.

As-built drawings

Record drawings updated to reflect field conditions and approved changes; they are the reference baseline for future inspection, maintenance, and modification work.