Standpipe and Hose System

References to follow for standpipe system design and installation

• NFPA 14: Standard for the Installation of Standpipe and Hose Systems
• NFPA 24: Standard for the Installation of Private Fire Service Mains and Their Appurtenances
• NFPA 20: Standard for the Installation of Stationary Pumps for Fire Protection
• NFPA 25: Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems

What is a Standpipe and Hose System?

NFPA 14 described a standpipe as

An arrangement of piping, valves, hose connections, and associated equipment installed in a building or structure, with the hose connections located in such a manner that water can be discharged in streams or spray patterns through attached hose and nozzles, for the purpose of extinguishing a fire, thereby protecting a building or structure and its contents in addition to protecting the occupants. [3.3.17, page 14-9, NFPA 14, 2016 Edition]

Hose System is a combination of

Hose Station: A combination of a hose rack or reel, hose nozzle, hose, and hose connection. [3.3.8, page 14-8, NFPA 14, 2016 Edition]

Hose Connection: A combination of equipment provided for connection of a hose to the standpipe system that includes a hose valve with a threaded outlet.[3.3.3.2, page 14-8, NFPA 14, 2016 Edition]

A standpipe and hose system is a simple system. It just delivers water during fire emergency. You need three things to build a standpipe and hose system.

• A pressurised water source
• A pipe network
• Hose stations

A pressurized water source can be a municipal water hydrant line. Where it is not available or feasible, we can use a set of fire pumps. Flow and pressure requirements dictate the selection of a fire pump set for every individual project. Hydraulic calculation software is very useful for calculating flow and pressure in a complex project.

A pipe network is a vital part of the standpipe and hose system which connects water source with hoses. It can be vertical or horizontal. Not only hose stations, but a pipe network also may contain Fire Hydrants, monitors, Fire Department Connection (FDC), isolation, and various types of valves.

Hose station as defined above can consist of hose reel or hose pipe or combination of both. It may contain 3 types of standpipe as described below.

Classes of Standpipe System

Class I System: It provides 2 1∕2 in. (65 mm) hose connections to supply water for use by fire department firefighters only during an emergency. In this class, there are no hosepipes attached, only landing valves. So the fire department usually carries hose packs with them. Usually 2 1∕2 in. landing valve installed within the landing area of stairways of buildings. This system requires high water pressure (at least 6.9 bar) and flow (at least 250 USGPM) makes it hard to control for an untrained people.

Class II System: It provides 1 1∕2 in. (40 mm) hose stations are often located in hallways of buildings to supply water for use primarily by trained personnel or by the fire department during initial response. It features permanently-installed 1.5” hoses in a cabinet that can be accessed by anyone in the event of a fire. This hose is normally found 100ft (30m) in length.

Class III System. It is a hybrid of Class I and Class II systems. It provides 1 1∕2 in. (40 mm) hose stations to supply water for use by trained personnel and 2 1∕2 in. (65 mm) hose connections to supply a larger volume of water for use by fire departments. Often times these connections provide a 2-1/2 inch reducer to a 1-1/2 hose connection.

Design Considerations:

The design of the standpipe system depends on

• Building height
• area per floor
• occupancy classification
• egress system design
• required flow rate
• residual pressure
• the distance of the hose connection from the source(s) of the water supply

The maximum pressure at any point in the system at any time shall not exceed 350 psi (24 bar). The pressure at a 1 1∕2 in. (40 mm) hose outlet should not exceed 100 psi (6.9 bar) and for 21∕2 in. (65 mm), not more than 175 psi (12.1 bar).

Hydraulically designed standpipe systems shall be designed to provide the minimum water flow rate of 250 USGPM (946 LPM) at a minimum residual pressure of 100 psi (6.9 bar) at the outlet of the hydraulically most remote 21∕2 in. (65 mm) hose connection and 250 USGPM (946 LPM) at 65 psi (4.5 bar) at the outlet of the hydraulically most remote 1 1∕2 in. (40 mm) hose station.

System Installation:

• Hose connections and hose stations shall be unobstructed and shall be located not less than 3 ft (0.9 m) or more than 5 ft (1.5 m) above the floor. This dimension comes from the measurement from the floor to the center of the hose valve.
• In each required exit stairway, we should use separate standpipe.
• Each standpipe can cover a travel distance of 200 ft (61 m) for sprinklered buildings and 130 ft(39.7 m) for nonsprinklered buildings.
• The standpipe must cover the accessible roof of a building.
• Standpipes shall be at least 4 in. (100 mm) in size. If it is a combined system (Standpipe plus Sprinkler) then it should be at least 6 in. (150 mm) in size.

Determining the fire Pump Capacity for standpipe system

No of Riser	No of Standpipe	No of most remote 21∕2 in. (65 mm) outlets	Pump flow capacity in USGPM
1	1	2	500
2	2	3	750
3	3	4	1000
4	4	5	1250

Pump head or pressure is determined by supplementing

• The minimum residual pressure required at the outlet of the hydraulically most remote 21∕2 in. (65 mm) hose connection ie 100 psi (6.9 bar)
• Friction loss in pipes, settings, and valves.
• Elevation loss

Operation and Maintainance:

A standpipe system installed in accordance with NFPA 14 shall be properly inspected, tested, and maintained by the property owner or an authorized representative in accordance with NFPA 25 to provide at least the same level of performance and protection as originally designed.