A fire extinguishing system with a hose cabinet is considered to be the entire compendium of pipes and accessories, sectioning valves, uprights and supports, which has connected a given number of stations or water nozzles to which the hoses are connected.
The design and installation of these systems is governed by NFPA 14, Standard for the Installation of Standpipe and Hose Systems.
Under normal conditions, the pipes in these systems are permanently pressurized with water and the valves in the hose cabinets are closed. When the cabinet hose is required to be used in a fire situation, the cabinet hose is pulled out and extended and the valve inside the cabinet is opened, the outlet of the water through the hose is controlled with the spout. When water begins to come out of the hose, the components of the upright will act, that is, the alarm bell will sound and the flow sensor or pressure sensor will send the signal to the main alarm panel of the plant, indicating the presence of a fire in those specific areas.
The discharge of water through the hose will reduce the pressure in the pipes, which when it reaches a predetermined value will start the main fire pump.
Class I: Enclosure with a 1 ½ ”connection and a 1 ½” hose
Class II.a: Cabinet with a 1 ½ ”connection and a 1 ½” hose, and a 2 ½ ”connection without a hose
Class II.b: Cabinet with a 2 ½ ”connection and a 2 ½” hose
Class I: Enclosure with a 2 ½ ”connection and a 2 ½” hose
Class II: Cabinet with a 1 ½ ”connection and a 1 ½” hose
Class III: Enclosure with a 1 ½ ”connection and a 1 ½” hose, and a 2 ½ ”connection without a hose The following are the components of a hose cabinet.
CLASS II CABINET, BY NFPA
CLASS III CABINET, BY NFPA
Source: Vicente Andrade