Red Seal Sprinkler Fitter flashcards
Red Seal Sprinkler Fitter · Build recall with a focused review session.
31 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Light hazard density
- Design density of 0.10 gpm/ft² over a 1,500 ft² remote area for light hazard occupancies such as offices, schools, and churches under NFPA 13 design rules.
- Ordinary Hazard Group 2
- Design density of 0.20 gpm/ft² over 1,500 ft²; applies to occupancies with moderate combustibility such as mercantile storage and parking garages.
- Hazen-Williams formula
- Friction loss formula p = 4.52 Q^1.85 / (C^1.85 d^4.87), giving psi per foot when Q is in gpm and inside diameter d is in inches.
- Elevation pressure change
- Pressure changes 0.433 psi per foot of elevation; add for rises and subtract for drops when calculating available pressure at a sprinkler.
- Minimum residual pressure
- NFPA 13 requires at least 7 psi (0.5 bar) residual pressure at the hydraulically most remote sprinkler to ensure adequate discharge from the head.
- Dry system area increase
- Dry pipe and double-interlock preaction systems require a 30 percent increase in the remote area because water delivery is delayed compared with wet systems.
- Hanger spacing steel pipe
- NFPA 13 permits hangers at 12 ft for pipe 1 in and smaller and up to 15 ft for larger Schedule 40 steel pipe, depending on diameter.
- Sway bracing intervals
- For seismic restraint of steel sprinkler pipe, lateral braces are spaced at 40 ft maximum and longitudinal braces at 80 ft maximum along the run.
- Thrust block purpose
- A concrete block installed at underground changes in direction, tees, and reducers to resist the unbalanced hydraulic thrust force and prevent joint separation.
- Groove depth gauge
- A gauge used to verify that the roll-groove or cut-groove depth matches the coupling manufacturer's specification before assembly of the joint.
- NPT thread taper
- National Pipe Taper threads have a 1:16 taper; proper engagement seals the joint, and thread sealant is applied to male threads only.
- Concrete anchor listing
- Fasteners used to support hangers in concrete must be listed for the application and installed per the manufacturer's edge distance and embedment requirements.
- Lockout tagout
- A procedure that isolates all energy sources, including water pressure, air, and electricity, and verifies zero energy before maintenance work begins.
- Confined space oxygen range
- Acceptable oxygen concentration for entry is 19.5 to 23 percent; outside this range entry is prohibited without supplied air and appropriate rescue provisions.
- Hot work fire watch
- A permit-based procedure requiring a fire watch, removal of combustibles within 35 ft (11 m), and a charged extinguisher during cutting, brazing, or welding.
- Sprinkler temperature color code
- Bulb or fusible link colors identify temperature rating: orange 135°F, red 155°F, yellow 175°F, green 200°F, blue 286°F, purple 360°F, black 440°F.
- Quick-response sprinkler RTI
- A sprinkler with a response time index of 50 (m·s)^0.5 or less, which activates faster and is required in certain occupancies for life safety.
- Deflector distance
- Standard spray pendent and upright deflectors are typically installed 1 to 12 in below noncombustible ceilings; combustible ceilings require 1 to 6 in.
- Spare sprinkler inventory
- At least six spare sprinklers of each type and temperature rating, plus a wrench, must be kept in a cabinet near the riser for replacement.
- Inspector's test connection
- A valve at the hydraulically most remote point, at least 1 in in size, used to simulate a single sprinkler flow and verify the waterflow alarm.
- Main drain test
- A flow test at the riser main drain that records static and residual pressure; a large drop from baseline indicates a supply or valve problem.
- Tamper switch supervision
- A device that sends a supervisory signal to the fire alarm panel when a control valve is not fully open, ensuring the valve position is monitored.
- Fire pump churn pressure
- The pressure produced by a fire pump at zero flow; it typically ranges from 100 to 140 percent of the rated head and must not exceed 140 percent.
- Fire pump 150% point
- At 150 percent of rated flow, a centrifugal fire pump must still produce at least 65 percent of its rated head per NFPA 20 testing requirements.
- Jockey pump set points
- The jockey pump starts at a pressure above the fire pump start point so it maintains system pressure without causing the main fire pump to start.
- Dry pipe valve trip test
- A test that opens the inspector's test valve to verify the dry pipe valve trips, water reaches the test connection within the allowed time, and alarms operate.
- Hydrostatic test pressure
- Systems are tested at 200 psi for two hours when working pressure is 150 psi or less, or at 50 psi above working pressure for higher-rated systems.
- Underground flushing velocity
- Underground mains are flushed at a minimum velocity of 10 ft/s to remove debris before connection to aboveground sprinkler piping and final testing.
- Clean agent hold time
- The period for which a clean agent concentration is maintained in an enclosure, typically 10 minutes, to ensure extinguishment before occupants re-enter.
- Deluge system operation
- A deluge valve is opened by a detection system, allowing water to flow to open sprinklers or nozzles that simultaneously discharge over the protected area.
- Double-interlock preaction
- A preaction system that requires both a detection signal and a sprinkler operation before the valve opens, reducing accidental water discharge.