Water spray nozzles are designed to spray water directly onto the hazard surface via a series of nozzles with a carefully predetermined spray pattern. They are suitable for a variety of special hazards including transformer, turbines and combustible liquid hazards and systems can be individually tailored to your needs.
High velocity systems – getting under the fire
High velocity systems are often used to protect equipment that incorporate heavy or medium oils; equipment such as transformers, circuit breakers, diesel engines and fuel oil storage tanks, turbo alternator lube oil systems and oil fired boilers.
The high velocity nozzles are specifically designed to discharge a jet of water at high speed. The water jet forms a cone of coarse spray of uniform density which is discharged over a defined area. The coarse spray is able to penetrate the flame zone and reach the surface of the burning oil. The turbulence created by the high velocity spray forms an oil-in-water emulsion on the surface of the oil that will not burn. This “emulsification” is the principal way the fire is extinguished, along with a cooling and smothering effect.
The shape of the spray cone, the fire area contacted and the water flow is all controlled by the nozzle specifications – the orifice size and the shape of the internal swirl plate – along with the water pressure and the orientation of the nozzle.
Medium velocity systems – cooling fire down
Medium velocity sprayers discharge a water spray of finely divided droplets at medium velocity. They are ideal for protecting hazards involving light oils where emulsification from high velocity sprayers is not possible. The fine spray has a high heat absorption rate so medium velocity sprayers are an effective method of protecting adjacent plant and structures from heat during a fire by providing a continuous cooling spray over the exposed surfaces. Keeping nearby equipment cool minimises damage and reduces the risk of explosion.
Medium velocity sprayers can be used in combination with other fire fighting systems – dry chemical and foam can be used effectively under the discharge. The fine spray also works to dilute and disperse flammable vapours. The sprayers use an external deflector to achieve the desired discharge angle and spray characteristics