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Specification For Fire Monitor Or Deluge Gun

Updated: Jan 21, 2022

A deluge gun, fire monitor, master stream or deck gun is an aimable, controllable high-capacity water jet for manual firefighting or automatic fire protection systems. Deluge guns are often designed to accommodate foam that has been injected into the upstream piping.

Deluge guns are often fitted to fireboats, tug boats, and on top of large fire trucks for use in manual firefighting efforts, where they can be aimed and operated by one firefighter and are used to deliver water or foam from outside the immediate area of the fire. Deluge guns are sometimes installed in fixed fire protection systems to protect against high hazards, such as aviation hangars and helicopter landing pads. Similarly, facilities with highly flammable material such as oil refineries may have permanently installed deluge guns. Most apparatus-mounted deluge guns can be directed by a single firefighter than a standard fire hose, which usually requires several. Deluge guns can be automatically positioned for fixed systems or may have portable designs. The latter option enables a firefighter to set up the gun to apply water to a blaze before leaving it in place to attend to other tasks.

A deluge gun can discharge 2,000 US gallons (7,600 litres) per minute or more. A master stream is a fire service term for a water stream of 350 US gallons (1,300 litres) per minute or more significant. It is delivered by a master stream device, such as a deck gun, deluge gun, or fire monitor. Master streams are often found at the end of aerial ladders, tele-squirt nozzles, or monitor nozzles. The high pressure that they require renders them unsuitable for handline use.


Monitor body, swivel joints, worm wheel, base flange and change over valve assembly shall be made of copper alloy conforming to IS:8442 Cl. 3.3.1. The body shall be of C.S. pipe heavy grade to IS: 1239, and base flange shall be of IS 226 or IS 6392. The water barrel shall be M.S. seamless pipe to IS:1239 heavy grade. Water nozzle shall be made from a copper alloy as specified in IS: 8442 Cl. 3.3.1. Pickup tube shall be made from rubber hose with chrome-plated brass strainer. Worm gear for traverse mechanism shall be made from phosphorus bronze or copper alloy as per Cl. 3.3.1 of IS: 8442. Nuts and bolts for base flange and change over valve shall confirm toIS:1367 Cl.10.9 and 12 respectively, while gasket shall be of CAF 40 to IS:2712. The drain valve shall conform to IS 778 class 2. Locks on swivels shall be made of brass to IS:291.

Design and Construction

The monitor shall be capable of discharging 1750 LPM at a pressure of 7 Kg/cm2. It shall have a traversing mechanism to give 360` in either direction in a horizontal plane and 125` in a vertical plane (80`, -45`) through the geared unit with a worm wheel operated by a separate hand wheel horizontal and vertical rotation. Swivel joints shall be provided with both horizontal and vertical rotation. The arrangement shall be such that the monitor shall be self-locking type and operated by a single person.

The valve shall be lever operated type. The monitor shall be mounted on a 100mm (4”) N.B. flat face slip-on type flange confirming to ANSI B 16.5 150lbs rating. Bolts and nuts for base flange shall have dimension confirming to ANSI B 16.5 Gasket shall be full face 3mmthick with drilling dimension same as for flange. Near the base flange, a drain connection shall be provided with a 15mm (1/2”) NB drain valve at the end of the pipe. The drain pipe shall be long enough to drain water away from the base flange. The threaded end of the water nozzle shall be hexagonal to facilitate the screwing of the nozzle on the water barrel with the nozzle spanner. Threads shall conform to IS:2643 (Pt.-1) with class A tolerance. The nozzle's inner surface shall be finished smooth and polished for the converging length of the nozzle.

Hydraulic Performance

The monitor shall be capable of discharging 1750lpm at a pressure of 7 Kg/cm2. The water jet's horizontal ranges shall be 60m and 45m, respectively, while the vertical throw shall be 30m and 20 to 25m respectively.

Quality and Finishing

All the parts shall have good quality and finish. All burrs and sharp edges shall be removed, and the nozzle shall have a smooth finish.

Anticorrosive Treatment and Painting

All steel components subject to direct water shall be hot-dipped galvanised to a minimum thickness of 0.12mm. The thickness of coating shall be measured as per IS:3203. External surfaces and non-ferrous components may be wetted with lead-tin alloy by an electrical deposition process. Monitor’s steel part shall be painted with fire red colour confirming to IS 5 shade no. 536 and the paint shall conform to IS:2932, and copper alloy part shall be polished.


The monitor shall be tested to fulfil the requirements of Hydraulic Performance. The entire assembly shall be hydraulically tested to a pressure of 2.1 MN/M2 (21 Kgf/Cm2) for 5 minutes without any leakage.


Each monitor shall be clearly and permanently marked with the following:

  • Manufacturer’s name or trademark

  • Year of manufacture

  • Purchaser’s name

Are you looking for help solving your facility's fire protection system, fire fighting system, and fire safety issues? Installation, Service & Maintenance, Upgrading & Repair? Connecting with an experienced Fire Protection Consultant at PSB Fire Engineers can help. At PSB Fire Engineers, we understand that your unique building needs unique fire protection systems. Our team is equipped to ensure you receive the fire protection you need to keep your facility and people safe from harm.

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