The Thermal Sensitivity Of Fire Sprinkler In Houston
A fusible metal link or tiny glass bulb protects most buildings from being destroyed by fires.
Most individuals assume that fire sprinklers are activated by alarms and/or smoke, but in an actual sense, heat is the main trigger used in most fire detection systems. Every sprinkler head is set off individually when it records a certain temperature reading in its area – reducing the chances of expensive water damage throughout an entire building because only a couple of sprinklers are required to put out a fire at its point of origin.
Are you thinking about buying sprinkler heads for your building’s fire detection system? Check out our wide selection of commercial concealed, sidewall, upright, and pendant fire sprinklers, or our variety of residential fire sprinklers. Read on to learn more about how fire sprinklers work as well as their importance in buildings.
How Fire Sprinklers Are Activated
Almost every sprinkler is kept shut by either a small glass bulb or a fusible metal link. A typical sprinkler has a plug or “pip cap” that is held in place by one of the above-mentioned systems of activation.
Glass bulbs that contain glycerin-based liquid are the most common type of activation mechanism used in fire sprinklers. Here’s how they function:
When a fire ignites, the air directly above it heats up very fast. This hot air rises towards the ceilings where most fire sprinklers are situated. When the air around the sprinkler heads gets to a certain temperature – usually around 57° C, 68° C, or 121° C (135° F, 155° F, or 250° F) – the glycerin liquid inside the bulb expands causing the bulb to break. In a wet sprinkler system, pressurized water in the system’s pipes is forced out of the plug and sprayed uniformly across the room by a deflector plate. The sprinklers continue spraying water across the room until the supply runs out or the main valve is shut.
In a dry sprinkler system, however, the sprinkler head causes the air pressure in the system’s pipes to drop instantly forcing the valve that holds back the water at the main supply to open. Pressurized water then flows through the pipes and is sprayed across the room by the sprinkler’s heads. This process typically lasts for just a minute. Preaction systems are triggered when a sprinkler’s temperature monitoring component is activated and a separate alarm is triggered.
The bulbs in the sprinklers usually come in 2 sizes; a 5 mm diameter that is used for standard response sprinklers and a 3 mm diameter that is used for quick response sprinklers. When installed in a small to medium-sized room, a 5 mm bulb usually breaks within about a minute after it gets into contact with the hot air from the fire.
The 3 mm bulbs used in quick response fire sprinklers tend to break faster. However, this doesn’t necessarily mean that they are more effective at fire damage prevention. There are many things you should consider before choosing which type of sprinklers to install in your building such as the National Fire Protection Association guidelines, building occupancy status, ambient room temperature, ceiling height, and many others.