Standpipe system types | NFPA 14

 Standpipe System Types According to NFPA 14

Standpipe system types according to NFPA 14

Standpipe System 

Fire extinguishing system consists of piping, valves, hose connections, hoses, & nozzles.

Classification of standpipe system

According to NFPA 14, standpipe system can be wet or dry, noting that: dry pipe system should be installed only where heat is not adequate to prevent freezing of water in any sections of the system.

A. Wet pipe standpipe system:

    A.1 Automatic wet

A standpipe system containing water at all times that is attached to a water supply capable of supplying the system demand at all times and that requires no action other than opening a hose valve to provide water at hose connections.

    A.2 Manual wet

A standpipe system containing water at all times that relies exclusively on the fire department connection to supply the system demand.

B. Dry pipe standpipe system:

    B.1 manual dry

A standpipe system with no permanently attached water supply that relies exclusively on the fire department connection to supply the system demand.

    B.2 Semiautomatic dry

A standpipe system permanently attached to a water supply that is capable of supplying the system demand at all times arranged through the use of a device such as a deluge valve and that requires activation of a remote-control device to provide to provide water at hose connection.

    B.3 Automatic dry

A standpipe system permanently attached to a water supply capable of supplying the system demand at all times, containing air or nitrogen under pressure, the release of which (as from opening a hose valve) opens a dry pipe valve to allow water to flow into the piping system and out of the opened hose valve.

Standpipe system classes:

Class I System. 

Components: 21∕2 in. hose connection

User: Fire departments

Flow rate: 250 gpm

Residual pressure: 100 PSI

Class II System. 

Components: 11∕2 in. hose stations

User: trained personnel or the fire department during initial response

Flow rate: 100 gpm

Residual pressure: 65 PSI

Class III System. 

Components: Combination of 11∕2 in. hose stations and 21∕2 in. hose connections

User: trained personnel for the 11∕2 in. hose stations or the fire department for the 21∕2 in. hose connections

Flow rate: 250 gpm for the 21/2 in hose or 100 gpm for the 11/2 in hose

Residual pressure: 100 PSI for the 21/2 in hose or 65 PSI for the 11/2 in hose

Selecting the proper system type for each class:

• Class I standpipe systems in non-high-rise buildings shall be permitted to be automatic dry, automatic wet, semiautomatic dry, manual dry, or manual wet in buildings not classified as high-rise buildings. Where system demand exceeds the pumping capabilities of fire department, class I standpipe shall not be permitted to be manual.
• Class I standpipe system in high rise buildings shall be automatic or semiautomatic.
• Class II and Class III standpipe systems with 11∕2 in. hose stations shall be automatic wet systems unless located in a facility where piping is subject to freezing and where a fire brigade is trained to operate the system without fire department intervention, in which case an automatic dry or semiautomatic dry system shall be permitted.
• Class III In non-high-rise buildings, the class I portion of the class III shall be permitted to be manual while the class II portion shall be automatic.
• Dry systems are not allowed for most Class II or Class III systems because of the risk to untrained users that would be created by delaying the availability of water.

References:

NFPA 14 - 2024 edition (Standard for The Installation of Standpipe & Hose Systems)

Read Also:

Determining number & location for hose connections

Class II standpipe system

Fire department connection according to NFPA 14

Where standpipe system is required

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