4 Types of Fire Sprinkler Systems Explained

  • July 2, 2021

There’s no doubt about it—fire sprinkler systems save lives. 

According to data from the National Fire Protection Association (NFPA), in 2010-2014, sprinklers effectively controlled 96 percent of fires when operated. In addition, injury to firefighters was 67 percent lower in situations where sprinklers were present.

Fire sprinkler systems are a must in most commercial buildings. But what sprinkler system should you use, how do they work, and how can you ensure that your sprinkler system protects you from a fire? We break down the answers to these questions below. 

Fire Sprinkler System Types

Not all sprinkler systems are created equal. NFPA expert Valerie Ziavras breaks down the four most common types of fire sprinkler systems and how they work below:  

1. Wet Pipe Fire Sprinkler System

Wet pipe fire sprinkler systems are the most popular. They’re found in most office buildings, schools, and high-rise residential buildings. As the name suggests, the pipes in this system contain water. The system works with a temperature gauge. When the fire sprinkler element reaches a specified temperature, the element breaks and activates the sprinkler. This type of system is simple to maintain. However, it does have its quirks. As water is actively present in the pipes, the facility must maintain a minimum temperature (usually around 40 degrees Fahrenheit). 

2. Dry Pipe Sprinkler System

A dry pipe sprinkler system works similarly to the wet pipe sprinkler system. However, instead of being filled with water, the systems are filled with nitrogen or pressurized air. The air’s pressure keeps the pipe valve closed, stopping the water from filling the pipes. The fire sprinkler is sensitive to sudden temperature increases. When something like that happens, the air pressure drops, and the dry valve pipe opens, flooding the sprinkler system and sending water out into the room. This system is perfect for cold areas and is common in unheated warehouses, parking garages or even attics. 

3. Pre-Action Fire Sprinkler System

A pre-action sprinkler system carries pressurized air, but the activation process is twofold. First, a smoke detector must sense a fire, which then signals the system to open the pre-activation valve, filling the pipes with water. Next, the sprinkler head itself must feel an increase in temperatures that’s indicative of a fire. If the temperature increase indicates a fire, then the sprinkler opens, extinguishing the flames. This type of system prevents accidental activations, making it perfect for museums, server rooms and data farms. 

4. Deluge Fire Sprinkler System

This type of sprinkler system is for big fires. Unlike the systems mentioned above, this system doesn’t have water in pipes or pressurized air. When a smoke detector detects a risk, the ‘deluge’ valve opens. The system sends water to all the fire sprinklers in the room, so the entire room is covered in water in a matter of minutes. It’s perfect for areas with highly combustible materials such as aircraft hangars, industrial plants and large-scale manufacturing businesses. 

Fire Sprinkler Inspections

At A&A Fire Protection, our inspectors come from an installation background and are trained in the proper code standards. The NFPA details all of the requisite codes and inspections in NFPA 25. An assessment of your system will consider the following steps:

  • Damage: Most importantly, a fire sprinkler inspection will look for damage to the system. According to the NFPA 25, sprinklers should be replaced if they show signs of leakage, corrosion, damage to the heat-responsive element (if applicable) and any other general damage that would prevent the sprinkler from doing its job adequately. 
  • Incorrect orientation: If a sprinkler is incorrectly oriented, it will not work and stop the fire as designed. Most of the problems with incorrect orientation are due to changes in the building, such as sagging ceilings. 
  • Missing sprinklers: An inspection will make sure to identify and replace any missing sprinklers. According to NFPA research, this is very important. For example, in half of the fires where sprinklers were ineffective, the water did not reach the fire.  
  • Clearance: An inspection will also check to ensure that any objects blocking the sprinklers are moved out of the way, ensuring that the water can reach the fire. 
  • Replacement parts: This step of the inspection ensures that there are enough replacement parts on hand (and the tools to install additional components).  

Our professionals offer inspection services for the following fire sprinkler systems:

  • Fire pump inspection
  • Wet pipe fire sprinkler inspection
  • Dry pipe fire sprinkler inspection
  • Pre-action fire sprinkler inspection
  • Deluge fire sprinkler inspection
  • Private fire hydrant inspection
  • Five-year interior obstruction investigation
  • Five-year flushing investigation 

All of our technicians are fully briefed and compliant with NFPA 25 and NFPA 15
If you have any questions about fire sprinkler systems and maintenance, our experts are standing by—contact us today.

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