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Fire Protection Handbook

Page 4: Fire Sprinklers

NFPA 25 National Fire Protection Association Inspection, Testing and Maintenance of Water-Based Fire Protection Systems.
NFPA 13 National Fire Protection Association Installation of Sprinkler Systems.
Accelerator A device used to accelerate the trip time in a dry system by channeling air into the intermediate chamber, thus destroying the pressure differential. Exception Vicataulic.
Alarm Valve A valve used on a wet system that has an intermediate chamber built into the valve that has ambient pressure. When water flows through the system, water enters the chamber, and flows through the bell line, allowing the electric bells or water motor gong to ring.
Antifreeze System A sprinkler system containing a mixture of water and antifreeze solution to prevent freezing. Operates same as a wet pipe system used in areas such as vestibules and loading docks in place of a dry pipe system.
Ball Valve A control valve used to isolate certain portions of a system. It only requires a quarter turn from fully open to fully closed.
Butterfly Valve An outside indicating valve used to isolate certain parts of a system.
Casing Relief Valve Located on the casing of a fire pump. During pump flow it helps to dissipate heat from the pump casing.
Check Valve A valve that allows water or air or any other substance to only fow in one direction.
Combined Standpipe & Sprinkler System Water piper outlets for use by the fire department and the automatic sprinklers.
Concealed Sprinkler Heads Covered by small metal plates and is flush with the ceiling. When heat from a fire increases, the plate falls away from the head.
Deluge System A sprinkler system that employs open sprinkler heads, a source of detection and a deluge valve. In the event of a fire, the detection system sends a signal, either electronically or pneumatically to the valve, releasing the valve, flowing water out of all open heads.
Dry Pipe System A system employing a dry pipe valve, air compressor or air source and associated piping. The dry pipe valve has air pressure above the dry seat and water below. In the event of a fire, a head fuses allowing the air pressure to reduce until the pressure differential is destroyed allowing water to flow into the system and out of the fused head.
Escutcheons Small metal discs that either cover or surround the sprinkler head. Escutcheons are used to seal gaps in the ceiling, maintain ratings and make sprinklers more aesthetically pleasing.
Electric Bell (Red) An alarm device mounted inside and outside to indicate a fire condition.
Exhauster A device used in conjunction with a dry pipe valve to accelerate the tripping of the dry pipe valve, either by pressurizing the intermediate chamber, exhausting the air pressure, or both.
FDC - Fire Department Connection Connection that the fire department can utilize to pump water into the system or standpipe to supplement the existing water supply. Also known as siamese connection or storz connection.
Fire Department Connection Caps Caps for the fire department connection to prevent items being placed that can block the flow of water.
Fire Pump Used to increase water flow and pressure. Driven by electric motor or diesel engine.
Foam System A sprinkler system that injects a solution of foam in the water to help suppress burning liquid fires.
Gate Valve OS&Y (Outside Screw and Yoke); A water control valve.
Gauge Located on the riser. It measures water or air pressure in a system. Must be replaced every five years.
Hangers Attached to building structure and are used to support fire protection piping.
Hose Station Contains the hose rack, hose nozzle, the hose and the hose connection. Can be used by the fire department to extinguish a fire.
Inspectors Test A valve located on the fire protection piping to activate the electrical alarm or water flow alarm.
Jockey Pump A small pump used in conjunction with a fire pump to maintain system pressure due to minimal leakage without causing high pressure surges.
Main Drain The primary drain connection located on the riser and also utilized as a flow test connections.
OS&Y - Outside Screw and Yoke This valve may be normally open or normally closed and requires a lock or supervision. Also known as Control Valve.
PIV - Post Indicator Valve Yard Post Indicator Valve - Self standing valve
Wall Post Indicator Valve - Wall mounted valve. This valve is normally open and requires a lock or supervision. Also known as Control Valve.
Pre Action System A type of dry system actuated by smoke, heat, or fused sprinkler head which releases the pre action valve, filling the system with water. Used in freezers, computer and file rooms, etc.
Pressure Reducing Valve A device that reduces the water to a predetermined set point.
Private Fire Service Mains Water mains, usually with fire hydrants, that are not owned by a municipality.
Retard Chamber A device used to absorb pressure changes, thus reducing the chance of a nuisance sprinkler alarm.
Riser The piping immediately above the underground run-in, which incorporates the control valve, dry pipe valve, alarm value, pre action valve or deluge valve.
Shut off Valve A control valve used to stop water flow to the system or portions of the system.
Siamese Connection Connection that the fire department can utilize to pump water into the system or standpipe to supplement the existing water supply. Also known as fire departmen connection or storz connection.
Spare Head Box A small red box hanging on the wall near the sprinkler riser. The box contains a set of spare sprinkler heads and a sprinkler head wrench. Under 300 sprinklers = 6 heads, 300-1000 = 12 heads, 1000 or more = 24 heads.
Sprinkler Head A fusible link or glass bulb in the sprinkler head melts when the heat of the fire reaches a set temperature. Red/Orange Bulbs 135-170, Green/Yellow 175-225, Blue 250-300, Purple 325-375, Black 400-650. There are many different types if sprinkler heads made: Flush, Pendent, Recessed, Sidewall, Upright, Fast Response, Extended Coverage, Open Sprinklers, and Quick Response are just a few. The type of head used is determind by the hazard.
Sprinkler Head Wrench A special wrench designed to change sprinkler heads. There are many different wrenches for different types of heads.
Standpipe System Consists of piping, valves, and hose connections that can be discharged in streams or spray patterns through the attached hose and nozzle.
Tamper Switch A switch connected to the control valve and fire panel to indicate a closed valve, which will result in complete failure or diminished performance of that system.
Trip Test An annual test performent on a dry system for indication of dry pipe valve performance and water flow to the most remote points on the system. Maximum time (60) seconds or less.
Water Flow Switch A device mounted to the sprinkler systems to initiate an alarm at the fire panel upon flow of water.
Water Motor Gong A bell that sounds when water flows through the sprinkler system. This bell sounds when water flows against a water wheel by means of a small peto inside the bell.
Water Tank A tank that supplies water for the systems.
Wet Pipe System A sprinkler system containing water that discharges immediately when the sprinkler head is opened by the heat of the fire.


Description of Annual Inspection

Wet Pipe Fire Sprinkler Systems
  • Operate all control valves and check for proper positioning. Main drain water supply pressure test, testing all tamper/flow alarms and a visual inspection of the piping and sprinkler heads will also be conducted.
Dry Pipe Fire Sprinkler Systems
  • Includes trip testing the dry valve, resetting and inspecting the interior of assembly. All low point drains will be drained and blown down. A full flow trip will be preformed every third year. All control valves will be checked for proper positioning, main drain water supply pressure test will be done, all tamper and flow alarms tested and a visual inspection of the piping and sprinkler heads will be conducted.
Pre-Action Fire Sprinkler Systems
  • Includes trip testing, inspection and resetting of the pre-action valve. All low point drains will be drained and blown down. All control valves will be checked for proper positioning, main drain water supply pressure test will be done and all tamper and flow alarms will be tested. Visual inspection of the piping and sprinkler heads will be conducted.
Standpipe Flow Test (Five Year Test)
  • Includes attaching 2½ inch hose to uppermost standpipe connection (if accessible) and fully flowing to determine static/residual water pressures as well as the pitot readings and gallons per minute. Standpipe will be visually inspected and all results documented.
Fire Pump Flow Test
  • Includes the flowing of pump and documenting suction and discharge pressures, amp, volt, gpm, and rpm readings at churn, 100% and 150% of rated capacity. Pump will be visually inspected and performance noted.
Fire Hydrants - Flow & Flush
  • Operation of hydrant

Did You Know...

  • A fire burning for one minute will grow three times its original size. In four minutes it will grow to 11 times its size and in six minutes it will reach 50 times its original size.
  • Despite what you see in movies, only one or two heads open and flow water during a fire. A fusible link in the sprinkler head melts when the heat of the fire reaches a set temperature.
  • 8-24 gallons of water per minute flow from a sprinkler head compared to the 125-250 gallons per minute released by a fire hose. The water damage from a sprinkler head is significantly less than what a fire hose discharges.
  • Installing sprinklers is comparable in cost to installing flooring. It can range anywhere from under a dollar to about $2.00 per square foot for new construction and up to $2.50 for retrofitting.

What Can Cause A Sprinkler System To Need Modification?

  • Change or addition of backflow preventer or water meter.
  • Change of building occupancy or use.
  • Change in building (walls, partitions, and additions).
  • Reduction in public water supplies (sometimes done in areas for water conservation).

Things You Should Know:

  • Never paint any fire sprinkler. It is recommended that the painters use aluminum foil instead of tape or plastic when covering heads to paint ceilings. It is easier to locate and remove after paint job is complete.
  • Never stack items close to fire sprinklers. (Storage should be at least 18" below fire sprinkler).
  • Never hang anything from a fire sprinkler head.
  • Always report damage to any part of a sprinkler system immediately.
  • Always make sure control valves are in the open position.
  • Vacant buildings with fire protection still need regular maintenance as required from local Fire Department.

What Is A Backflow Preventer?

  • A backflow preventer is a cross connection control device mandated by the Local Water Authority and the Environmental Protection Agency to stop or prevent the occurrence of reversing the normal direction of the flow of liquid, gases, or solid substances back in to the public potables (drinking) water supply.
  • Because water is an important and necessary part of our lives, one way to save our water supply is by not allowing our water to become contaminated.
  • The authority having jurisdiction in your area mandates testing by a licensed technician at regularly schedule intervals. They also require testing results to be recorded. Specially designed equipment is used to insure accurate testing.
  • When a backflow preventer test fails, repairs are required so that the backflow preventer can be placed back into working order. This can be due to debris in the backflow; fluctuations can cause debris and dirt to enter the water line, then enters into the backflow preventer, damages the check valves and can make them fail. Normal everyday debris can also enter the checks. Even in new construction a new backflow can fail (these devices are immediately tested upon installation).
  • In new construction the underground is flushed but there still can be debris in the water/piping, thus causing the check valve not to close properly and the device to fail. Jurisdictions have the authority to require installation of these devices as well as turn off the water supply to a facility for not properly maintaining their backflow preventers. Fees can be charged for water to be turned back on once testing or repairs are made.

Description of Annual Inspection of Backflow Prevention Devices

  • Control valves and check valves are tested to make sure they are functioning properly. With a series of openings and closings of the test clocks, technicians can determine that the check valve is closed properly and is holding, thus preventing a backflow of water. All devices will be tested/certified as required by the authority having jusidiction. If devices are located in a "pit" or "vault" they will be tested in accordance with OHSA requirements for confined space entry.

Has Your System Been Internally Inspected?

  • A sprinkler pipe that has never been flushed can be filled with a combination of scale, rust and other debris. Not only does it impede the flow of water in the pipes, but in a fire condition it could plug up the sprinkler heads, which would make the system useless.
  • NFPA 25 13.2.1 mandates internal pipe inspections every five years. This is due to the debris that can accumulate in pipe over a period of years. While it is mostly present in dry systems because they are filled with compressed air that contains moisture, it can also be found in wet systems but will take a longer time to accumulate.
  • During an internal inspection, the system valve, system riser, a cross main, and a branch line should be examined internally. If the results show a sufficient amount of materials present that could obstruct the sprinklers, a complete flushing program should be conducted.

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