Fire sprinkler system: Pre-action
A complex system deserves a team that knows those complexities inside and out.
What we do

Valley Fire Protection has many years of experience designing and building complete systems, including the highly complex pre-action systems, which require the highest level of skill to design and build.

  • Non-interlock pre-action systems
  • Single interlock pre-action systems
  • Double interlock pre-action systems

Pre-action sprinklers

Pre-action sprinklers are one of several of the key sprinkler systems in use today at commercial properties. The pre-action systems employ concepts similar to dry pipe systems in that the pipes do not have water in them until the system is triggered. The big difference between is that in some pre-action systems, the pipes are filled with pressurized air (often nitrogen, which is used to help fire protection professionals to detect leaks). A detection system will trigger a pre-action valve to open, which creates a wet pipe environment. But the water will only flow out of individual sprinkler heads as needed.

Pre-action sprinkler system for commercial properties

Commercial properties need a 24-hour fire protection system to ensure the contents of the property are covered. This includes the contents of the property during business hours, which includes employees – the most important part of any business. However, a sprinkler system is also there to douse flames when the business is closed. A pre-action system is a common system used in commercial properties where the contents are of high value. This often includes computer rooms, museums, data centers, libraries and etc.

Design and build the new pre-action fire sprinkler system

No two businesses are alike, which is why there can be no one-size-fits-all pre-action sprinkler system. Whether it’s new construction or retrofitting an older system, commercial properties need to be able to count on their fire protection contractor to design and build a pre-action system that will be a perfect match for their needs. Fortunately, Valley Fire Protection has many years of experience designing and building complete systems, including the highly complex pre-action systems, which require the highest level of skill to design and build.

Pre-action sprinkler systems installation in water sensitive areas

Water is the most often used combatant against fire. However, there are situations where introducing water to an environment can almost carry as much danger to the contents of a building as fire. For example, an art museum filled with important historical and invaluable pieces that are centuries old cannot be put into a situation where a false alarm douses them in water. Therefore, the pre-action system is a perfect option because it has the checks and balances that other systems lack.

"I just wanted to say thank you to the both of you for doing your jobs as well as you do. It is a real pleasure dealing with a company with professionals such as you two. My alarm system is inspected and ready to go (on the same day as you received the contract/quote I would like to ad), my sprinkler system is always taken care of without incident (no leaks or valves left open and your technician is always on time), and I still use the subcontractor I found through you guys for the extinguishers. Again, thank you for the excellent job that you do. Be sure to let me know when you do extinguishers in house so I can contact you for a quote."
– Tim Traggardh – Site Engineer
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Pre-action sprinkler repair and maintenance for a variety of industries

Because pre-action systems are more complex, they require extra repair and maintenance compared to other types of systems. Regardless of what industry you’re in, keeping a regular maintenance schedule is important so that when the system is called upon, it will work flawlessly. Your fire protection contractor should have the necessary skills to spot a trouble spot before it becomes an issue with your business. Furthermore, when any part of the system requires repair, your contractor needs to have the tools and skills necessary to quickly and efficiently make them so that you can go on with business as usual.

Single interlock and double interlock pre-action systems

Pre-action sprinklers come in two different varieties: single interlock and double interlock. Your fire protection contractor will determine which is the best for your commercial property. A single interlock system is one that operates quite similarly to a dry pipe system in that it only requires a single event to set the water in motion, which is the detection of a fire, heat or smoke.

A double interlock system requires that two events occur before the valve releases the water. First, a fire, heat or smoke is detected. Second, the automatic sprinklers detect heat or fire, which will initiate the opening of the valve that allows water to fill the pipes and release from the sprinkler heads.

Our Services

Valley Fire Protection’s staff works directly with both architects and professional technicians to produce the designs. Our collaboration allows us to configure systems that meet the specific requirements of your job, no matter how large or small.


We understand the importance of following schedules, which is why our project managers work closely with the design-build staff, material suppliers and installers. Our experts will ensure the process runs smoothly, finishes both on-time and within budget.

Repair & maintenance

Whether it is a pre-quoted and pre-scheduled service or an emergency repair, we offer peace of mind to our customers.


We are on call 24/7/365. Valley Fire Protection has a highly trained team of 30 service technicians with fully equipped vehicles positioned throughout Chicagoland and Indiana.

Advantages and disadvantages to using a pre-action pipe fire sprinkler system

The biggest advantage to using a pre-action system is that it requires two things to happen for the water to be released, which means there is little to no fear that a faulty alarm will flood a commercial property that is not under threat. Water sensitive environments are therefore big proponents of this type of system.

The disadvantages include the complexity of this type of system, which means higher installation and maintenance costs. They are also difficult to modify. Given that they are complex systems, the failure rate is higher unless they are regularly inspected.

Finding the right pre-action fire suppression system to your business

At Valley Fire Protection, we have extensive knowledge in designing, building, installing and retrofitting pre-action systems. Furthermore, we offer preventative maintenance services and repairs to our clients. Whether you’re retrofitting a building or establishing a system in a new building, we have the experience you need to have the job done right. A complex system deserves a team that knows those complexities inside and out. Contact us today and let’s talk about the best system for your commercial property.

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Specializing in design, installation, maintenance and service of automatic fire sprinkler systems. Our time-tested fire protection solutions come with a 100% guarantee. We have been serving Chicagoland for over 40 years. Let us serve you!