MA Fire Sprinkler flashcards

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

Light hazard density

NFPA 13 light hazard design density is 0.10 gpm/ft² over a 1,500 ft² design area for wet systems, with the area adjusted per density-area curves.

Ordinary Group 1 density

Ordinary Group 1 occupancies require 0.15 gpm/ft² over 1,500 ft² under NFPA 13 density-area design.

Ordinary Group 2 density

Ordinary Group 2 occupancies require 0.20 gpm/ft² over 1,500 ft² under NFPA 13 density-area design.

Dry system design area

NFPA 13 requires a 30% increase in the design area for dry pipe and preaction systems compared to wet systems.

Minimum end-of-line pressure

NFPA 13 requires at least 7 psi at a single sprinkler at the end of a line, or 15 psi where multiple sprinklers are at the end.

Hazen-Williams C factor

C=120 for black steel pipe and C=100 for galvanized or cement-lined pipe in NFPA 13 hydraulic calculations.

Elevation pressure

Each foot of elevation change equals 0.433 psi; add this to the demand when the system is above the supply.

Flow test extrapolation

Available pressure at the system demand is extrapolated from a hydrant flow test using the 1.85 power relationship between flow and pressure drop.

Safety margin

A margin, commonly 10-15 psi, is subtracted from the available supply curve to ensure the system demand is met.

Domestic demand addition

When sprinkler and domestic systems share a supply, the domestic demand must be added to the sprinkler demand in the calculation.

13R height limit

NFPA 13R applies to residential occupancies up to and including four stories above grade; taller buildings require NFPA 13.

13D two-sprinkler rule

NFPA 13D systems must be designed to supply at least two sprinklers simultaneously at the design pressure.

13R design density

NFPA 13R requires 0.05 gpm/ft² over the room area with a minimum of two sprinklers, or the listed head flow if greater.

13D water supply duration

NFPA 13D systems typically require a water supply capable of supplying the design demand for 7 minutes for a single-family dwelling.

13D omission areas

NFPA 13D permits omission of sprinklers in closets, bathrooms, garages, and certain concealed spaces under defined conditions.

Weekly wet system check

NFPA 25 requires weekly inspection of wet system gauge readings and control valve positions.

Quarterly alarm test

NFPA 25 requires quarterly testing of waterflow alarm devices, valve supervisory switches, and main drain flow on wet systems.

Annual dry valve trip

NFPA 25 requires an annual partial trip test of dry pipe valves and a full-flow trip test every three years.

Sprinkler head replacement

Fast-response sprinkler heads must be replaced at 20 years and standard-response heads at 50 years, or per the manufacturer's listing.

Gauge calibration interval

NFPA 25 requires gauges to be replaced or recalibrated every 5 years.

Impairment procedure

When a system is impaired, notify the fire department and owner, post impairment tags, and implement a fire watch where required.

Fire pump churn pressure

Fire pump shutoff (churn) pressure is typically 100-140% of rated pressure and must not exceed the system component rating.

Fire pump 150% flow

At 150% of rated flow, a fire pump must produce not less than 65% of its rated pressure.

Fire pump test header

Fire pumps require a test header sized for 150% of rated flow and an annual flow test at churn, 100%, and 150%.

Standpipe classes

Class I provides 2½ in outlets for fire department use, Class II provides 1½ in outlets for occupants, and Class III provides both.

Standpipe flow test

NFPA 25 requires standpipe systems to be flow tested every 5 years and hydrostatically tested at 200 psi or 50 psi above static.

Private main minimum size

NFPA 24 requires private fire service mains to be sized for the required flow, typically 6 in for hydrant mains and 4 in for sprinkler-only mains.

Working plan contents

Working plans must show piping, sprinkler locations, hanger details, hydraulic calculations, and water supply data, signed by the responsible designer.

Hydrostatic test

NFPA 13 requires a hydrostatic test at 200 psi for 2 hours, or 50 psi above working pressure if higher.

Sprinkler contractor license

Massachusetts requires sprinkler contractors to hold a state license and employ licensed sprinkler fitters to perform installation work.

Permit requirement

A fire department permit is required before installing, altering, or repairing a sprinkler system in Massachusetts.

Final acceptance

A certificate of completion or final fire department inspection is required before a sprinkler system is placed in service.