Do you notice the fire sprinklers when you enter in a Tulsa or Oklahoma City building? Does it make you feel safer to see them in your hotel room or office space? If you’re not in the fire protection industry, you may never notice sprinkler heads hanging from the ceilings, but they are a vital part of a building’s fire protection system and are invaluable. Automatic fire sprinklers provide, not only life-saving benefits, but also can contain or even extinguish a fire and often greatly limit what would otherwise be devastating property damage.

Did you realize there were different types of fire sprinklers? We’ll discuss the basic differences of these common types…

Wet Pipe Fire Sprinkler Systems

As their name suggests, the overhead piping connected to these closed sprinkler heads is “wet” or contains water under pressure at all times. Thus, when a fire causes one of the sprinkler heads to activate, that sprinkler head immediately releases the water that is in the overhead piping.

This type of sprinkler is the most common type, the simplest, and is usually less expensive to maintain. However, these sprinkler systems cannot be installed in areas where the temperatures will reach below 40F because the water in the pipes would freeze. Wet pipe fire sprinklers should be inspected and maintained regularly to prevent corrosion, leaks, or other damage. These types of sprinklers, though, are highly reliable and simple to install and maintain. They are also simple to restore to working order after they have been activated.

Dry Pipe Fire Sprinkler Systems

Interestingly, this type of sprinkler still releases water upon activation. The water, however, is not constantly in the overhead piping but is helddry fire sprinklers back behind a main dry-pipe valve in a heated area of the building. Instead, the pipes contain pressurized air or nitrogen. When a fire activates a sprinkler head, the air pressure drops, and then the main valve opens to release the water into the piping system and then is discharged through the sprinkler heads.

These fire sprinklers systems are installed in areas that could reach below 40F such as warehouses, walk-in refrigerators, loading docks, etc. Of course, because the water is not directly in the pipes, but has to travel through them, there is a short, up to 60 second delay in how quickly the water is released from the sprinkler head. Dry pipe systems can be installed in conjunction with larger wet pipe systems in areas that may freeze.

Pre-Action Fire Sprinkler Systems

This fire sprinkler system is much like the dry pipe system but has more safety mechanisms in place to prevent water damage from any accidental activation.  These are like dry pipe systems in that water is not stored directly in the sprinkler piping. The piping is often filled with pressurized air. However, unlike the dry pipe system, water in pre-action systems is held back by an electronic pre-action valve that is activated by an independent fire detection system, not by the sprinkler heads.

“Water will not discharge from the system until the fire has generated a sufficient quantity of heat to cause operation of one or more sprinklers. In essence, the system appears as a wet-pipe system once the pre-action valve operates,” OSHA noted.

In a double-interlock pre-action system, two things must activate before water is allowed into the piping. Both the independent fire detection system and the sprinkler heads must be activated before water is released into the piping system. If one is activated and not the other, the water will not be released. This adds a double layer of safety against accidental activation and water damage.

In addition, a pre-action system can monitor the air pressure and sound an alarm if pressure dropped because of a leak or other problem without opening the valve to allow water through.

These sprinkler systems are thus designed to protect water sensitive facilities such as libraries, museums, data centers, and other telecommunication centers.

Deluge Fire Sprinkler System

When a deluge of water is needed all at once to put out a rapidly growing and particularly dangerous fire, a deluge fire sprinkler system will generally be used. These systems are thus used where there are especially hazardous or combustible materials such in aircraft hangers, chemical facilities, electrical transformers, etc.

Similar to pre-action and dry pipe systems, water is not in the piping until the deluge system is activated. However, all of the sprinklers in a deluge system are open. Thus, when the system is activated, water is discharged from all of the sprinklers because they are all open. A deluge system is thus not activated by heat sensing elements in the sprinklers, but by a separate fire detection system that then activates the deluge valve to open and release water into the piping and then to the sprinklers.

Because this type of fire sprinkler system is used for particularly dangerous and rapidly growing fires, it needs a significant water supply to deliver large amounts of water very quickly.

If your Tulsa or Oklahoma City business needs a fire sprinkler system installed or repaired, the fire protection system experts at Mac Systems can design, install, inspect, and maintain every aspect of your sprinkler system. We can help you decide on the best type of fire sprinkler system for your business needs.