KY Fire Sprinkler flashcards
KY 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
- NFPA 13 light hazard design density starts at 0.10 gpm/ft² over a 1,500 ft² design area; actual density may be adjusted along the density/area curve.
- Sprinkler deflector clearance
- Standard spray sprinklers require at least 1 in. (25 mm) of clearance between the deflector and the ceiling to allow the spray pattern to develop properly.
- Sprinkler temperature rating
- Ordinary sprinklers are rated 135-170°F; intermediate 175-225°F; high 250-300°F. Select a rating at least 25°F above the maximum ceiling temperature.
- Hanger spacing
- NFPA 13 permits hangers at 12 ft maximum for pipe 1 in. and smaller and 15 ft maximum for pipe 1¼ in. and larger, with a hanger near each change in direction.
- Quick-response design area reduction
- Quick-response sprinklers may reduce the design area by 30% (minimum 1,500 ft²) on wet systems in light or ordinary hazard occupancies where the standard permits.
- NFPA 13R height limit
- NFPA 13R applies to residential occupancies up to and including four stories above grade plane; buildings taller than four stories require full NFPA 13 protection.
- 13D water supply duration
- NFPA 13D requires the water supply to meet the system demand for at least 10 minutes, or 7 minutes where a tank with automatic refill or a municipal supply is used.
- 13R design density
- NFPA 13R design density is 0.05 gpm/ft² over the most remote room or 0.10 gpm/ft² over the four most remote sprinklers, whichever is greater.
- 13R sprinkler spacing
- Residential sprinklers under NFPA 13R are spaced a maximum of 12 ft apart and 6 ft from walls, with maximum coverage of 144 ft² per sprinkler.
- Class I standpipe
- A Class I standpipe provides 2½ in. hose valves for fire department use and requires 100 psi residual pressure at the topmost outlet.
- Class II standpipe
- A Class II standpipe provides 1½ in. hose valves with attached hose for occupant use and requires 65 psi residual pressure at the topmost outlet.
- Standpipe flow demand
- Standpipe systems require 500 gpm for the most remote standpipe plus 250 gpm for each additional standpipe, with a maximum total of 1,250 gpm.
- Hose valve height
- Standpipe hose valves must be located 3 to 6 ft above the floor, accessible, and equipped with caps and chains to protect the threads.
- Fire pump 150% rule
- A fire pump must deliver at least 65% of rated pressure at 150% of rated flow, and at least 95% of rated pressure at zero flow (shutoff).
- Fire pump churn pressure
- Churn pressure (shutoff) must not exceed 140% of the pump's rated pressure to protect the system components from overpressure.
- Jockey pump setting
- The jockey pump is set to start about 10 psi above the fire pump start pressure and stops at the fire pump start pressure, maintaining system pressure.
- Fire pump weekly test
- NFPA 25 requires a weekly no-flow churn test for electric fire pumps and inspection of diesel fuel level and battery condition monthly.
- Private main minimum size
- NFPA 24 requires private fire service mains to be at least 4 in. for hydrant supply and 6 in. where the main serves a fire department connection.
- Underground hydrostatic test
- Private fire mains are hydrostatically tested at 200 psi for 2 hours, or 50 psi above working pressure if greater, before backfilling where possible.
- Thrust block locations
- Thrust blocks or restrained joints are required at all changes in direction, tees, dead ends, and hydrant branches to resist unbalanced pressure forces.
- Main drain test
- The main drain test records static and residual pressure; a drop of more than 10% from the previous test indicates a problem with the water supply.
- Sprinkler replacement interval
- Fast-response sprinklers are replaced at 20 years and then every 10 years; standard-response sprinklers at 50 years and then every 10 years.
- Dry pipe valve trip test
- NFPA 25 requires an annual dry pipe valve trip test with the main drain open, recording trip time and air pressure for comparison with prior years.
- 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.
- Hazen-Williams C factors
- C = 120 for black steel, 140 for cement-lined pipe, and 150 for copper and PVC/CPVC; use the value matching the installed pipe material.
- Water velocity limit
- Sprinkler piping is typically designed to keep water velocity at or below 20 ft/s for steel pipe to limit erosion and noise; 15 ft/s is common.
- Hydraulic safety margin
- Add 10-15 psi to the calculated system demand to account for uncertainties and ensure the supply curve stays above the demand curve.
- Working plan contents
- Working plans must be drawn to scale and show all risers, cross mains, branch lines, sprinklers, valves, pipe sizes, and hanger locations.
- Plan approval requirement
- Sprinkler plans must be approved by the authority having jurisdiction before installation; approved plans must be kept on site during construction.
- Kentucky sprinkler license
- Kentucky requires a licensed sprinkler contractor and certified installer; the license number must appear on the permit application and submitted plans.
- Kentucky Fire Prevention Code
- The Kentucky Fire Prevention Code is based on the International Fire Code and is enforced by the State Fire Marshal, with local amendments permitted.
- Hot work fire watch
- A hot work permit is required for welding, cutting, or grinding, and a fire watch must be maintained for at least 30 minutes after the work is complete.