0. Fire Detection and Suppression
Chapter 6
Sprinkler Systems

1. Effectiveness of Sprinkler Systems
96 percent reliable when installed and maintained properly
Insurance carrier report, 1984–1987
Sprinkler systems controlled 98 percent of fires
One sprinkler controlled 29 percent of fires
Ten or fewer sprinklers controlled 75 percent of fires
Sprinkler Systems

2. Reasons for Installing Sprinklers
Code requirements
Insurance incentives
General fire protection of life and property
Building design flexibility
Sprinkler Systems

3. Applicable Standards
NFPA 13, Standard for the Installation of Sprinkler Systems
NFPA 13D, Standard for the Installation of Sprinkler Systems in One-and Two-Family Dwellings and Mobile Homes
NFPA 13R, Standard for the Installation of Sprinkler Systems in Residential Occupancies up to Four Stories in Height
(Continued)
Sprinkler Systems

4. Applicable Standards (cont.)
NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems
Underwriters Laboratories
Insurance carriers
Sprinkler Systems

5. Components of Sprinkler Systems
Piping
Valves
Fire department connections
Sprinkler Systems

6. Sprinklers
Sense the fire, react to that sense, and then deliver the water to the fire area
Heat-sensitive device
Fusible link
Frangible bulb
Temperature ratings: determined by maximum air temperature expected at level of the sprinkler under normal conditions
(Continued)
Sprinkler Systems

7. Sprinklers (cont.) Sprinkler Response Time Deflector Component
Inevitable delay
Response time index (RTI)
Deflector Component
Forms discharge pattern
Basic configurations
Upright
Pendant
Sidewall
Water spray nozzle
(Continued)
Sprinkler Systems

8. Sprinklers (cont.) Early Suppression Fast Response Sprinklers
Thermal Sensitivity
Actual Delivered Density
Deflector design and discharge orifice
Sprinkler Systems

9. Sprinkler System Piping
Materials
Steel
Copper tubing
Galvanized
Plastic
(Continued)
Sprinkler Systems

10. Sprinkler System Piping (cont.)
Functions (Fig. 6.16)
Water supply main
System riser
Sprig-up
Riser
Feed main
Cross main
Branch line
Sprinkler Systems

11. Valves Control valves Indicating/nonindicating
Outside screw and yoke (OS&Y) (Fig 6.18)
Post indicator valve (PIV) (Fig 6.19)
Wall post indicator valve (WPIV) (Fig 6.20)
Indicating butterfly valve (Fig. 6.21)
(Continued)
Sprinkler Systems

12. Valves Control valves (cont.) Mechanism Security Gate (Fig 6.22)
Butterfly (Fig. 6.23)
Ball
Security
Chain/locks
Electric supervision
(Continued)
Sprinkler Systems

13. Valves (cont.) Operating valves Check valves (Figs. 6.24 and 6.25)
Automatic drain valves
Globe valves
Stop or cock valves
Sprinkler Systems

14. Fire Department Connections
Number and sizes of connections (Fig. 6.29)
Check valve
Location relative to main supply valve
Single-riser systems
Multiple-riser systems
Sprinkler Systems

15. Types of Sprinkler Systems
Wet-pipe sprinkler system (Fig. 6.31)
Alarm check valve (Fig. 6.33)
Waterflow indicator (Fig 6.34)
Local and fire department notification systems
Antifreeze systems (Fig. 6.38)
(Continued)
Sprinkler Systems

16. Types of Sprinkler Systems (cont.)
Dry-pipe sprinkler system (Fig. 6.39)
Dry-pipe valves
Quick-opening devices
Accelerator (Fig. 6.42)
Exhauster (Fig. 6.43)
Operational sequence
1. Heat from a fire causes the sprinkler to activate.
2. Pressurized air contained in the piping begins to flow through the open sprinkler.
(Continued)
Sprinkler Systems

17. Types of Sprinkler Systems
Dry-pipe sprinkler system
Operational sequence (cont.)
3. After a slight drop in air pressure, the quick-opening device (if present) activates to accelerate the removal of air from the piping.
4. Once the air pressure is reduced sufficiently, the dry-pipe valve trips open. The interior clapper is held in the open position by a latch.
(Continued)
Sprinkler Systems

18. Types of Sprinkler Systems
Dry-pipe sprinkler system
Operational sequence (cont.)
5. Water enters the intermediate chamber of the dry-pipe valve. This automatically forces the automatic drip valve closed and begins the flow of water through alarm-signaling equipment.
6. Water flows through the entire piping system and is discharged through the open sprinkler.
(Continued)
Sprinkler Systems

19. Types of Sprinkler Systems (cont.)
Deluge sprinkler system
Design and purpose
Operation
Electrical
Pneumatic
Hydraulic
(Continued)
Sprinkler Systems

20. Types of Sprinkler Systems
Deluge sprinkler system (cont.)
Operational sequence
1. A product-of-combustion (heat, smoke, or flame) detector senses the presence of a fire condition, or an individual in the area discovers a fire in progress.
2. The fire detection system sends a signal to the deluge valve, causing the valve to open, or the individual who discovers the fire manually trips the deluge valve.
(Continued)
Sprinkler Systems

21. Types of Sprinkler Systems
Deluge sprinkler system
Operational sequence (cont.)
3. As water enters the deluge valve and the piping, a pressure switch is activated that transmits an alarm either locally or to a supervising station. A water motor gong (if present) is activated.
4. Water flows through all open sprinklers simultaneously.
(Continued)
Sprinkler Systems

22. Types of Sprinkler Systems (cont.)
Preaction sprinkler system
Mechanisms
Single-interlock
Non-interlock
Double-interlock
(Continued)
Sprinkler Systems

23. Types of Sprinkler Systems
Preaction sprinkler system (cont.)
Operational sequence
1. Product-of-combustion (heat, smoke, or flame) detector senses presence of fire condition.
2. Fire detection system sends signal to preaction valve, causing valve to open.
3. Sensors in piping system detect flow of water into system and trigger waterflow fire alarm.
4. When level of heat at a sprinkler reaches appropriate temperature, sprinkler opens and water flows through orifice.
Sprinkler Systems

24. Sprinkler Systems for Industrial Storage Occupancies
High fuel loads
High loss potential
Large undivided areas
Large concentration of value in a single fire area
Very high stockpiling with narrow aisles
(Continued)
Sprinkler Systems

25. Sprinkler Systems for Industrial Storage Occupancies (cont.)
Classification of commodities
Classes
Class I: Generally noncombustible, stored on wooden pallets in ordinary packaging
Class II: Noncombustible commodity, packaged in wooden crates or multi-layered cardboard cartons
Class III: Commodities made of combustible materials such as wood, paper, or certain plastics, irrespective of pallets or packaging
(Continued)
Sprinkler Systems

26. Sprinkler Systems for Industrial Storage Occupancies
Classification of commodities
Classes (cont.)
Class IV: Meets one of the following criteria:
1. Constructed of Group B plastics.
2. Consists of free-flowing Group A plastics.
3. Contains an appreciable amount of Group A plastics. Remaining materials may be wood, metal, paper, natural or synthetic fibers, or Groups B & C plastics.
Plastics: Groups A, B, and C
— Determining the classification
Sprinkler Systems

27. Inspecting and Testing Sprinkler Systems
Preinspection procedures
Review records of prior inspections and identify make, model, and type of equipment, and area protected by the system.
Wear appropriate clothing for dirty locations such as attics and basements. Protective clothing may be necessary for certain manufacturing areas.
(Continued)
Sprinkler Systems

28. Inspecting and Testing Sprinkler Systems
Preinspection procedures (cont.)
Obtain permission from the plant management before performing any inspection.
Never personally or physically operate, adjust, manipulate, alter, or handle any sprinkler devices or equipment during situations other than emergencies or planned training sessions.
If equipment is electronically supervised, plant personnel should notify alarm-monitoring organization before and after testing (Continued)
Sprinkler Systems

29. Inspecting and Testing Sprinkler Systems (cont.)
Signs of weakness
Obstructions
Extra sprinklers
Sprinkler piping, hangers, and seismic braces
(Continued)
Sprinkler Systems

30. Inspecting and Testing Sprinkler Systems (cont.)
Changes in building occupancy
What are the sprinkler system design criteria?
Has a change in the occupancy occurred?
Have combustibles been added that will contribute to a greater fire load or a more rapid fire spread?
Have alterations caused a need for the reconfiguration of sprinklers?
(Continued)
Sprinkler Systems

31. Inspecting and Testing Sprinkler Systems (cont.)
Inspecting and testing wet-pipe sprinkler systems
Inspections
Valves
Sprinklers
Piping
Water supply
(Continued)
Sprinkler Systems

32. Inspecting and Testing Sprinkler Systems
Inspecting and testing wet-pipe sprinkler systems (cont.)
Acceptance tests
Flushing of underground connections
Hydrostatic tests
Wet-pipe system testing
Alarm test
Waterflow alarm test
Main drain test (Continued)
Sprinkler Systems

33. Inspecting and Testing Sprinkler Systems (cont.)
Inspecting and testing dry-pipe sprinkler systems
Inspection points
All indicating control valves open and properly supervised.
Air pressure readings correspond to previously recorded readings.
The ball-drip valve moves freely and allows trapped water to seep out of the fire department connection.
(Continued)
Sprinkler Systems

34. Inspecting and Testing Sprinkler Systems (cont.)
Inspecting and testing dry-pipe sprinkler systems
Inspection points (cont.)
Velocity drip valve beneath intermediate chamber is free to move and allow trapped water to seep out.
Fire department connection threads unobstructed, in good condition, and caps in place with gaskets intact. Identification signs in place and readable.
Any drum drips are drained to eliminate the moisture trapped in the low areas of the system.
(Continued)
Sprinkler Systems

35. Inspecting and Testing Sprinkler Systems (cont.)
Inspecting and testing dry-pipe sprinkler systems
Inspection points (cont.)
During freezing weather, dry-pipe valve enclosure heating device keeps dry-pipe valve temperature at or above 40° F (4° C).
Priming water at correct level.
NOTE: If the system is equipped with a quick-opening device, opening the priming water test line could trip the system.
(Continued)
Sprinkler Systems

36. Inspecting and Testing Sprinkler Systems
Inspecting and testing dry-pipe sprinkler systems
Inspection points (cont.)
The system’s air pressure is maintained at 15 to 20 psi (105 kPa to 140 kPa) above the trip point, and no air leaks are indicated by a rapid or steady air loss. If inspectors note excessive air pressure, they should have the system drained down.
The system air compressor is approved for sprinkler system use, well maintained, operable, and of sufficient size.
(Continued)
Sprinkler Systems

37. Inspecting and Testing Sprinkler Systems
Inspecting and testing dry-pipe sprinkler systems (cont.)
Acceptance tests
Flushing of underground connections
Hydrostatic tests
Dry-pipe system testing
Main drain test
Trip test
(Continued)
Sprinkler Systems

38. Inspecting and Testing Sprinkler Systems (cont.)
Inspecting and testing deluge and preaction sprinkler systems
Main drain and alarm tests
Trip test
Sprinkler Systems

39. Restoring Sprinkler Systems
General guidelines
For safety reasons when practical, one fire company may be left on the scene to verify restoration of the system.
A chief officer may continue to recheck the occupancy until the system is restored.
Responsibility for the building’s welfare may be turned over to the occupant or a responsible agent of the occupant.
(Continued)
Sprinkler Systems

40. Restoring Sprinkler Systems
General guidelines (cont.)
Sprinklers that have activated must be replaced with identical sprinklers if at all possible.
Restoring wet-pipe sprinkler systems
Restoring dry-pipe sprinkler systems
Restoring deluge and preaction sprinkler systems
Sprinkler Systems

41. Sprinkler System Impairment Control
Planned interruptions
Maintenance
Testing
Building renovation
Unplanned interruptions
Frozen pipes
Broken pipes
Equipment failures
(Continued)
Sprinkler Systems

42. Sprinkler System Impairment Control (cont.)
Fire safety measures when sprinkler system impairment occurs may include:
Fire guards
Suspension of hazardous operations
Additional manual equipment
Sprinkler Systems

43. Residential Sprinkler Systems
Standards
NFPA 13D, Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes
NFPA 13R, Standard for the Installation of Sprinkler Systems in Residential Occupancies Up To and Including Four Stories in Height
(Continued)
Sprinkler Systems

44. Residential Sprinkler Systems (cont.)
Residential modifications
Residential sprinklers were designed to be fast response.
Water supply requirements were reduced to levels appropriate for life safety.
Areas of coverage for sprinklers were adjusted based on sprinkler design and typical residential fire loads.
(Continued)
Sprinkler Systems

45. Residential Sprinkler Systems
Residential modifications (cont.)
Alarms were made simpler and more realistic for residential applications and smoke detectors may also be used for notification.
Valve arrangements were made so that they would be unobtrusive in a common residence.
Sprinklers are designed to discharge water high on the walls.
(Continued)
Sprinkler Systems

46. Residential Sprinkler Systems (cont.)
Residential sprinklers versus conventional sprinklers
Speed of operation
Distribution pattern
Residential sprinkler piping
(Continued)
Sprinkler Systems

47. Residential Sprinkler Systems (cont.)
Water supply and flow rate requirements
18 gpm (68 L/min) for any single sprinkler. If there are two or more sprinklers, each requires 13 gpm (49 L/min) as a maximum required water supply. In addition, the water supply needs only to supply this flow rate for 10 minutes
(Continued)
Sprinkler Systems

48. Residential Sprinkler Systems
Water supply and flow rate requirements (cont.)
For larger multiple dwellings, the designed flow rates are greater. NFPA 13R requires 18 gpm (68 L/min) for a single sprinkler and not less than 13 gpm (49 L/min) to a maximum of four sprinklers. The water supply for these larger buildings is required to supply the sprinklers for 30 minutes.
Sprinkler Systems