Waterflow Alarms and Fire Department Connection for Sprinkler System

This article is about Waterflow Alarms and Fire Department Connection for Sprinkler System and Technical Requirement in commercial buildings, plants and refinery projects related to Plumbing Engineering System as per international codes and standards.

Waterflow Alarms and Fire Department Connection for Sprinkler System

Waterflow Alarms

1. Local waterflow alarms shall be provided on all sprinkler systems having more than 20 sprinklers. (NFPA 13 Para 4.15.1.1.1)
2. Waterflow alarm apparatus shall be listed for the service and so constructed and installed that any flow of water from a sprinkler system equal to or greater than that from a single automatic sprinkler of the smallest orifice size installed on the system will result in an audible alarm on the premises within 5 minutes after such flow begins and until such flow stops. (NFPA 13 Para 2.9.1).
3. The alarm apparatus for a wet pipe system shall consist of a listed alarm check valve or other listed waterflow-detecting alarm device with the necessary attachments required to give an alarm. (NFPA 13 Para 2.9.2.1)
4. The alarm apparatus for deluge and preaction systems shall consist of alarms actuated independently by the detection system and the flow of water. (NFPA 13 Para 2.9.2.3).
5. Paddle-type waterflow alarm indicators shall be installed in wet systems only. (NFPA 13 Para 2.9.2.4.)
6. An alarm unit shall include a listed mechanical alarm, horn, or siren or a listed electric gong, bell, speaker, horn, or siren. (NFPA 13 Para 2.9.3.1.)
7. Outdoor water motor operated or electrically operated bells shall be weatherproofed and guarded. (NFPA 13 Para 2.9.3.2.)
8. All piping to water motor operated devices shall be galvanized or brass or other corrosion resistant material acceptable under this standard and of a size not less than 3/4″” (20 mm) nominal pipe size. (NFPA 13 Para 2.9.4)
9. Piping between the sprinkler system and a pressure actuated alarm-initiating device shall be galvanized or of non-ferrous metal or other approved (acceptable to the Authority Having Jurisdiction) corrosion resistant material of not less than 3/8″” (9.5 mm) nominal pipe size. (NFPA 13 Para 2.9.3.4)
10. Electrically operated alarm attachments forming part of an auxiliary, central station, local protective, proprietary, or remote station signalling system shall be installed in accordance with NFPA 72, National Fire Alarm Code. (NFPA 13 Para 2.9.5.1)
11. Outdoor electric alarm devices shall be listed for outdoor use. (NFPA 13 Para 2.9.5.2)
12. Drains from alarm devices shall be so arranged that there will be no overflowing at the alarm apparatus, at domestic connections, or elsewhere with the sprinkler drains wide open and under system pressure. (NFPA 13 Para 2.9.6)
13. “On each alarm check valve used under conditions of variable water pressure, a retarding device shall be installed. Valves shall be provided in the connections to retarding devices to permit repair or removal without shutting off sprinklers; these valves shall be so arranged that they can be locked or sealed in the open position. (NFPA 13 Para 4.15.1.1.2)
14. Alarm valves shall be fitted with an alarm by-pass test connection for an electric alarm switch, water motor gong, or both. The alarm by-pass test connection for alarm valves shall be made on the water supply side of the system and provided with a control valve and drain for the alarm piping.
15. Exception: The alarm bypass test connection for alarm valves shall be made on the water supply side of the system and provided with a control valve and drain for the alarm piping. (NFPA 13 Para 4.15.1.1.3)
16. A check valve shall be installed in the pipe connection from the intermediate chamber of a dry pipe valve.(NFPA 13 Para 4.15.1.1.3)
17. An indicating control valve shall be installed in the connection to pressure type contactors or water motor operated alarm devices. Such valves shall be sealed, locked, or electrically supervised in the open position. The control valve for the retarding chamber on alarm check valves shall be acccepted as complying with this paragraph. (NFPA 13 Para 4.15.1.1.4)

Fire Department Connection

1. A listed check valve shall be installed in each fire departments connection. (NFPA 13 Para 4.15.2.4.1)
2. There shall be no shut off valve in the fire department connection piping. (NFPA 13 Para 4.15.2.4.2)
3. A fire department connection shall be provided as described in accordance with Figure 4.15.2.1 (See Attachment 1).
   Exception 1:Buildings located in remote areas that are inaccessible for fire department support.
   Exception 2: Large capacity deluge systems exceeding the pumping capacity of the fire department.
   Exception 3:Single storey buildings not exceeding 2000 ft² (186 m²) in area. (NFPA 13 Para 4.15.2.1)
4. The size of the pipe for the fire department connection shall be a minimum of 4″” (102 mm) for fire engine connections and 6″” (152 mm) for fire boat connections.
   Exception: A single-outlet fire department connection shall be acceptable where piped to a 3″” (76 mm) or smaller riser. (NFPA 13 Para 4.15.2.2)
5. The fire department connection shall be on the system side of the water supply check valve. (NFPA 13 Para 4.15.2.3.1)
6. Where a fire department connection services only a portion of a building, a sign shall be attached indicationg the portions of the building being served. (NFPA 13 Para 4.15.2.3.4)
7. Fire department connections shall be located and arranged so that hose lines can be readily and conveniently attached. Each fire department connection to sprinkler systems shall be designated by a sign having raised or engraved letters at least 1″” (25.4 mm) in height on plate or fitting reading service design– for example, AUTOSPKR, OPEN SPKR., AND STANDPIPE.
   (NFPA 13 Para 8.16.2.4.6) “
8. Each fire department connection to sprinkler systems shall be designated by a sign having raised or engraved letters at least 1″” (25.4 mm) in height on plate or fitting reading service design– for example, “”AUTOSPKR, OPEN SPKR., AND STANDPIPE””. A sign shall also indicate the pressure required at the inlets to deliver the greatest system demand.
   Exception: The sign shall not be required where the system demand pressure is less than 150 psi (10.3 bar). (NFPA 13 Para 4.15.2.3.5.)
9. “Fire department connections shall not be connected on the suction side of fire pumps. (NFPA 13 Para 4.15.2.3.6.)
10. The required pressure gauges shall be listed and shall have a a maximum limit of not less than twice the normal system working pressure at the point where installed. They shall be installed to permit removal. (NFPA 13 Para 4.15.3.2)

International Codes and Standard References for Waterflow Alarms and Fire Department Connection

Sprinkler and Standpipe Piping and Fitting Installation
NFPA 13 –Installation of Sprinkler Systems