A sprinkler system is an active fire protection method. It consists of a water supply system with adequate flow and pressure, and piping that connects fire sprinklers to the water supply. When a fire occurs, the water sprinklers release a stream of water to put the fire out. This protection method is highly effective and is very cost effective.
Wet-pipe sprinkler system
A wet-pipe sprinkler system contains pressurized stagnant water. This water is subject to corrosion processes, characterized by a series of cathodic reactions. This process consumes the dissolved oxygen present in the water. As a result, the water in the system becomes corroded very quickly.
In some instances, this process may be slow, as it takes 60 seconds to reach the sprinkler head. The resulting delay can cause more damage before fire suppression can begin. In such cases, a dry-pipe system may be more appropriate. This type of sprinkler system also tends to be less expensive to install and maintain. However, this system should never be used in temperatures below 40 degrees F.
The calculation method for wet-pipe sprinkler systems is based on the calculation of water pressure. This method accounts for pressure losses and gains in the piping and the elevation between the sprinkler head and the source. It also accounts for momentum pressure resulting from the velocity of water inside the piping. The calculations are typically performed using computer software. Previously, calculations were done manually.
One type of wet-pipe system is a simple fire sprinkler system that works by placing water inside pipes that are pressurized. The water will then discharge onto the fire when a sprinkler activates. The simple design and low maintenance requirements of this system make it a popular choice. However, it cannot be used in cold temperatures and must be manually operated.
Fusible link sprinkler system
A Fusible link sprinkler system uses a spring assembly and a link assembly to deploy the sprinkler head. The spring assembly is generally disposed on the shoulder 106 of the sprinkler head. The spring assembly has an upper surface that engages the fusible link assembly 26. Once the spring element is engaged with the nozzle, the adjustable member 46 turns within the bore 44 to compress the resilient means 100. This will then cause the members 60 and 68 to separate from the sprinkler head.
The fusible link sprinkler head consists of two metal plates joined by a heat-sensitive alloy. This heat-sensitive element fuses together when the specified temperature is met. When this happens, the metal plates detach and the water is released. As long as the temperature is low enough, the fusible link sprinkler system is an effective fire protection system.
The fusible link sprinkler system operates by activating the sprinklers when the temperature of the surrounding air reaches a certain temperature. The fusible link has an inherent nonlinear load curve, which reduces the complexity of assembly. Hence, it is less expensive than conventional structures.
Residential fire sprinklers typically activate when the temperature of a room reaches 56oC. Large warehouses, on the other hand, require temperatures of 63oC or more. This temperature rating is usually stamped on the fusible link and the glass bulb.
Single interlock sprinkler system
In cases where sprinklers are not sufficient to contain a fire, a single interlock sprinkler system can be a viable solution. This system is similar to a double interlock system, except that it has a lower temperature rating and will not operate until a heat detector is activated.
The primary advantage of a single interlock system is that the water will only flow when a fire detector activates it. A double interlock system is similar, but uses two types of fire detectors. Both systems require that a smoke detector and a heat detector are activated before water will flow.
The Single interlock system is similar to a dry pipe system, except that it requires a fire detection event to activate the system. A fire detector can trigger a pre-action valve which opens once the fire has been detected. The water is then allowed to flow through the piping system and out of the fire sprinkler heads. This system also reduces the amount of time required to get the water to the area.
Single interlock systems may be the ideal solution for most fire-prone buildings. The compartmentalization they provide prevents a fire from spreading and helps contain it before water supplies run out.
