DE Fire Sprinkler flashcards
DE Fire Sprinkler · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Light hazard density
- Light hazard design density is 0.10 gpm/ft² over a 1,500 ft² remote area, per NFPA 13 density/area curves, unless quick-response reduction applies.
- Maximum sprinkler spacing
- Standard spray sprinklers in light hazard shall be spaced not more than 15 ft apart and not more than 7 ft 6 in from walls, per NFPA 13.
- Deflector distance
- Standard spray sprinkler deflectors must be 1 in to 12 in below the ceiling; extended-coverage sprinklers allow 1 in to 18 in per listing.
- Remote area shape
- The remote area for hydraulic calculation is rectangular with length parallel to branch lines, or a shape with a 1.2√A aspect ratio per NFPA 13.
- Quick-response reduction
- Quick-response sprinklers in wet systems may reduce the design area by up to 30% when the remote area is ≤1,000 ft² and ceiling height ≤10 ft, per NFPA 13.
- Extended coverage area
- Extended-coverage sprinklers allow larger coverage per sprinkler (e.g., 400 ft² for light hazard) and greater spacing, as listed by the manufacturer.
- Residential sprinkler density
- NFPA 13D residential sprinklers require a minimum density of 0.05–0.10 gpm/ft² depending on the number of heads flowing, with maximum 400 ft² coverage per head.
- NFPA 13 scope
- NFPA 13 covers design and installation of automatic sprinkler systems for commercial, industrial, and high-rise residential occupancies, including water supply and hydraulic calculations.
- Hanger spacing steel pipe
- Steel pipe 1 in and smaller requires hangers at ≤12 ft intervals; 1¼ in and larger at ≤15 ft; hangers within 3 ft of sprinklers and 6 ft of direction changes.
- Hydrostatic test pressure
- Sprinkler piping must be hydrostatically tested at 200 psi for 2 hours, or 50 psi above working pressure if working pressure exceeds 150 psi, per NFPA 13.
- Spare sprinkler cabinet
- A spare sprinkler cabinet must contain at least 6 spare sprinklers of each type and temperature rating, or 2% of the total, whichever is greater, plus a wrench.
- Control valve supervision
- All sprinkler control valves must be supervised open using tamper switches or locked open, with supervisory signals monitored per NFPA 72.
- Pipe schedule limits
- The pipe schedule method is limited to specific pipe sizes and hazards; most new systems require hydraulic calculations per NFPA 13.
- Underground main size
- Fire service underground mains shall be at least 6 in in diameter unless hydraulic calculations justify a smaller size, per NFPA 13 and NFPA 24.
- Hazen-Williams formula
- Friction loss P = 4.52 Q^1.85 / (C^1.85 d^4.87), where Q is gpm, d is inside diameter in inches, and C is the roughness coefficient (steel 120, copper 150).
- Flow test calculation
- Available pressure at demand flow = static − (static − residual) × (Q_demand / Q_test)^1.85, using a flow test's static, residual, and flow values.
- Safety margin
- A safety margin of 10 psi or 5% of the demand pressure, whichever is greater, must exist between the water supply and system demand at the base of the riser.
- Hose stream allowance
- Hose allowance added to sprinkler demand is 100 gpm for light hazard, 250 gpm for ordinary hazard, and 500 gpm for extra hazard, per NFPA 13.
- Elevation pressure loss
- Each foot of elevation change equals 0.433 psi; add for rises and subtract for drops when calculating available pressure at sprinklers.
- Fire pump churn pressure
- Centrifugal fire pump shutoff (churn) pressure must not exceed 140% of rated pressure; the pump should be selected so demand is within 150% of rated flow.
- Backflow preventer loss
- Friction loss through backflow preventers and water meters must be included in hydraulic calculations using manufacturer-supplied curves at the design flow.
- Velocity limit
- Sprinkler piping velocity should generally not exceed 20 ft/s in supply mains and 10–15 ft/s in branch lines to limit friction loss and noise.
- Weekly inspection
- Weekly inspections include verifying control valves are open, gauges read normal, and fire pump status is operational, per NFPA 25.
- Main drain test
- A main drain flow test records static and residual pressure; a drop exceeding 10% from the baseline may indicate a supply obstruction or valve closure.
- Dry pipe trip test
- Dry pipe valves must be trip-tested annually; water must reach the test valve within 60 seconds of trip, and results are recorded in the ITM log.
- Fire pump flow test
- Annual fire pump flow tests measure pressure at churn, 100%, and 150% of rated flow; results are compared to baseline and kept on site.
- Gauge calibration
- Sprinkler system gauges must be replaced or recalibrated every 5 years, and alarm/supervisory circuits tested per NFPA 72.
- Impairment procedure
- When a system is impaired, notify the fire department and insurer, establish a fire watch, and follow NFPA 25 impairment handling until restoration.
- Spare head replacement
- Painted, corroded, or damaged sprinklers must be replaced with matching type and temperature rating; spare stock must be maintained in the cabinet.
- Delaware code adoption
- Delaware adopts NFPA 13, 13R, 13D, and NFPA 25 through the State Fire Prevention Regulations, with local amendments in Wilmington and New Castle County.
- Plan review permit
- Construction documents must be submitted to the Delaware State Fire Marshal or local AHJ for plan review and permit before sprinkler installation begins.
- Contractor licensing
- Delaware sprinkler contractors need a business license and certified fitters; verify licensing with the Delaware Division of Fire Prevention before contracting.