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Types of Sprinkler Installations Sprinkler System v Sprinkler Installation A Sprinkler System is the ENTIRE means of providing sprinkler protection on the premises. This includes the incoming water mains, pumps, tanks, supply pipes to buildings and the sprinkler installations within the buildings Sprinkler Installation is PART OF a sprinkler system comprising a control valve and the downstream pipework to the sprinkler heads, within a building.
The alarm valve is located immediately above the main stop valve. Its function is to open soon after a sprinkler head is activated and water flows in an installation, some water being diverted to drive an alarm motor, which is a water turbine that rotates and causes a clapper to strike a gong and thus raise the alarm. Depending upon the design requirements and the environment in which the system is installed, different configuration of valves will be used.
Control Valve Set
Types of Installation
The supply of water to a sprinkler installation is controlled by a set of valves which varies according to the type of installation. There are two principal valves, the main stop valve and the alarm valve. These can be called several different names but mean the same thing i.e. installation control valves; installation control valve set; valve set; ICV; control valves. The main stop valve controls water entering the installation. It is a handwheeloperated valve and should be kept locked in its fully open position by a padlock and strap. It should be in a position which is readily accessible, preferably near a building’s main entrance. Nearby, on an outside wall, should be the sign:
WET TYPE Permanently filled with water under pressure and the most common type of sprinkler installations installed in premises. Used in heated buildings, where there is no possibility of the water freezing, the ambient temperature should not exceed 95°C. Wet installations can deliver water to the fire as soon as a sprinkler head operates and is the preferred type of sprinkler installation.
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DRY PIPE Appropriate for applications either where there is a danger of the water in the pipes freezing or in situations where there may be temperatures above about 70ºC. The pipes on the ‘downstream’ side of the installation control valves are charged with air or an inert gas under sufficient pressure to prevent the entry of water into the delivery pipework. There should be a permanent automatic supply of air or gas to maintain the pressure in the pipework. Once the first sprinkler head operates the compressed air or gas escapes through the open sprinkler head and water discharges on to the fire.
