High-velocity water spray systems are used for the protection of fire hazards at transformers, circuit breakers, turbo-alternators, lube oil systems, oil-fired boilers and similar hazards that contain heavy oils/flammable liquids (flash point above 65C).

Medium Velocity water spray systems are used in flammable liquid (flash point below 65C) and paint storage areas, boiler/switchgear/generator rooms, exhaust ducts, packing areas comprising corrugated boxes, woods and so forth. Besides, it can extinguish the fire from polar solvents or alcohol.

Usually, Nozzles are selected based on the K factor that created the spray patterns at different angles, pressures, and distances. For that reason, identifying accurate K-factors based on the application area is important to increase system efficiency.

K factor details elaborated in NFPA 13 guideline for installation of sprinkler systems.

Extinguishment Process

Fire hazards controlled by cooling, smothering, diluting or emulsifying the flammable or combustible particles and reducing surface temperature.

Surface Cooling: The cooling process is developed by the conversion of water to steam, where the water particles absorb the heat from the surface of the burning substance.

According to FM global reference during the steam conversion process, 1 lb of water absorbs 1150 Btu at 60 F. At the point when flammable vapors are no more in the burning material, and the surface of the substance is cooled, then the fire is mitigated.

Smothering: In the Smothering process, water spray is converted to steam by the burning material heat and expands the volume more or less 17,050 times. At the same time, the steam envelops the fire zone as well as excluded oxygen, therefore, extinguishing the fire.

Emulsification:  Emulsification process is gained when two immiscible liquids like water and oil are forced to combine, rather than a homogenous solution that creates mechanical agitation. Such emulsion shapes a blanket over a fire, and coats the adjacent surfaces, preventing the spread of the fire.

Dilution of water-dissolvable fluids is typically a minor factor in extinguishing a fire.

How Does Water Spray Fixed System Work?

Water Spray Fixed System operates on a deluge system for fast application of water in the system. Where the deluge valve is the water control valve of the entire system, it is quick to release hydraulically or electrically operated diaphragm valves.

Deluge systems are utilized, whereas an entire territory should be protected instantly rather than by zone or location of the source of heat or fire.

It is a totally dry pipe system that means no water in the pipe in a normal situation, and all sprinkler heads are open. The detection system detects heats or fire and sends a signal to panels. Then the fire alarm system initiates alarm, and at the same time, the control panel emits a signal to the deluge valve to open up.

And finally, the deluge system allows the water following out of the nozzles in a specific directional pattern to extinguish the fire.

The system can be conducted automatically by automatic fire detection and alarm system or manually or both.

Technical operation of water spray deluge system and deluge fire sprinkler system is almost similar, but the main differentiating point is the way of water flow from the heads. Nozzles spray water in a specific spray pattern, including circle, full, oval, fan, or narrow jet.

Therefore, the water can comply with a three-dimensional hazard.

Specialties

The water spray system is rapid in response, high water discharge but less damage compared to the conventional sprinkler system. No chemicals, no risk of asphyxiation compared to gas suppression systems.

A fixed spray system is perfect for oil & gas and power sectors that contain flammable gaseous and liquid materials, electrical hazards, combustible materials, and propellants.

This system is very specific, works well in high hazards areas because of its quick flood ability to prevent fire. But for an efficient result, the K factor and specific psi should be considered correctly during design and installation.

EMACO Water Spray Fixed System Application Scope