Table of Contents
Fire sprinklers work because high heat triggers the sprinkler system. When a blaze ignites, the air directly above it heats rapidly. Most sprinkler heads feature a glass bulb filled with a glycerin-based liquid. This liquid expands when it comes in contact with air heated to between 135 and 165 degrees.
How does a fire sprinkler go off?
Sprinklers are highly reliable devices that are activated by heat. They will only go off if there is a fire which increases the heat beyond the sprinkler trigger point (typically 135 to 165°F (57.2 to 73.9°C)). “When a fire occurs, every sprinkler head goes off.” Sprinkler heads are individually activated by fire.
What causes fire sprinkler heads to break?
Accidental discharges of fire sprinklers typically occur due to inadvertent overheating, freezing, mechanical damage, corrosion, manufacturing or installation defect. In addition, if something comes into contact with the sprinkler head and breaks the glass bulb, the sprinkler would then be activated.
How much water flows from a fire sprinkler head?
A sprinkler system should be designed so that water flow is at least 15 gallons per minute (gpm) and up to a maximum of 40 gpm. Regardless of the type, the standard requires that the water supply for a home fire sprinkler system accommodate one or two operating sprinklers for a period of seven to 10 minutes.
What is inside a sprinkler head?
In some sprinklers, the plug is made of an alloy called Wood’s metal, a mixture of bismuth, lead, tin, and cadmium that melts at a relatively low temperature. In other sprinklers, the plug is a small glass bulb full of a glycerin-based liquid designed to expand and shatter when it gets hot.
Can a sprinkler head go off by itself?
Fire sprinkler heads, if tampered with, struck by tools or equipment, or damaged, can also go off without warning. Make sure your employees know never to hang seasonal decorations from sprinkler heads, which is a very common cause of accidental fire sprinkler activation discharge.
Can a candle set off a sprinkler?
While there’s a small chance of setting off your fire alarm while smoking, vaping, cooking, or burning candles or incense, rest assured that these items won’t set off the fire sprinklers. The only exception to this statement is if you hold a lighter or candle flame directly up to a sprinkler head.
How long do fire sprinkler heads last?
Adapted from Table 5.1.1.2 about testing in the 2016 Edition of NFPA 25 Type Frequency Sprinklers At 75 years and every 5 years thereafter Dry Sprinklers 10 years and every 10 years thereafter Sprinklers (extra high or greater temperature solder type) 5 years Fast Response Sprinklers At 20 years and every 10 years thereafter.
At what temperature does a sprinkler head go off?
What DOES Set Off Fire Sprinklers? Fire sprinkler systems are actually quite sophisticated, and are designed to be heat sensitive so that sprinklers only activate when the temperatures rise to fire-induced temps, usually somewhere between 155 to 165 degrees Fahrenheit.
What is the standard pressure for fire sprinkler?
➢ Fire sprinklers typically require only 7 pounds-per-square-inch (psi) to operate, which is less than the minimum required pressure for residential plumbing fixtures.
What water pressure is needed for sprinklers?
Water pressure is measured in pounds per square inch – also called psi. The average water pressure for most homes and businesses is between 30 psi and 50 psi; most sprinkler systems are designed to use pressures of around 30 psi.
How much water does a fire sprinkler system need?
To feed a fire sprinkler system the water main must satisfy the following criteria: There must be a dedicated* 32-50mm (cat 1), 50mm (cat 2), 50-63mm (cat 3) incoming water main into the property.
How do you identify a fire sprinkler head?
Let’s get to it: a sprinkler identification number consists of one or two letters followed by three or four numbers. That code is imprinted on each sprinkler’s deflector—the thin metallic part furthest away from a sprinkler’s threaded inlet.
What is the red liquid in a sprinkler head?
The liquid in the sprinkler head comes in a variety of colors, which indicates the temperature required to activate the head: Orange – 135° F. Red – 155° F. Yellow – 174° F.
What are the 2 types of sprinkler heads?
Types of Sprinkler Heads for Fire Protection Pendent Fire Sprinkler Head. Upright Fire Sprinkler Head. Sidewall Fire Sprinkler Head. Concealed Fire Sprinkler Head.
What causes a sprinkler head to activate?
Fire sprinklers work because high heat triggers the sprinkler system. When a blaze ignites, the air directly above it heats rapidly. This hot air rises and spreads along the ceiling. When the liquid expands, it shatters its glass confines and the sprinkler head activates.
What happens when a sprinkler head breaks?
A severely broken sprinkler head tends to shoot water off in the air, similar to a geyser. Even if you shut off that zone, the water can still run through the pipes and flood your lawn. This flood can potentially damage the landscape around the sprinkler zone. No matter where you live, water isn’t going to be free.
How hard is it to break a sprinkler head?
It is possible not to hit it hard enough or to hit it on an angle which won’t set it off. Typically this just bends it or damages it and it then needs to be replaced. However, most sprinklers work by using a glass bulb inside which melts from heat and snaps the value open.
