Have you ever wondered what happens during a fire sprinkler inspection? It really depends on whether it’s a wet or dry sprinkler system.

Let’s take a closer look at each.

What Happens During a Wet Fire Sprinkler System Inspection?

For a wet system, we will do an inspection of all the valves at the riser itself and check the gauges to make sure they are in date or calibrated.

Then, we’ll make sure there are spare heads for the system and wrenches for the spare heads in a spare head box.

After that, we’ll look for anything out of the ordinary on the system. For example, areas with no protection or loaded heads from grease and/or dust. Some sprinkler heads may need to be cleaned or replaced depending on the condition.

We make sure there is proper coverage (spacing-wise), proper sprinkler heads and we check all the piping for visible corrosion, rust, leaks and etc..

We also check the hangers, making sure all the hangers are secured properly and that there’s proper spacing. Then, we do a “main drain”.

The “main drain” is when we open up the main drain valve and check the pressure readings on the gauges. We operate all control valves to make sure the supervisory switches come in and report to the panel.

The last step is to do an actual flow to operate the alarm, time it and make sure the alarm comes in at a passing time [60-90 seconds]. We record the time and then record it on the tag.

What Happens During a Dry Fire Sprinkler System Inspection?

The main difference between a wet and dry inspection is that a dry system needs to trip out the dry valve. We do what is called a “choke trip”.

A “choke trip” is when we trip test the dry valves, simulating an actual fire, while “choking” the water kept below from coming up.

Dry systems are in areas that freeze, like outside canopies and attics. So the pipes are filled with air and the water is kept below. Every year, we trip that valve to make sure the valve trips. We time it and we get a pressure drop on how much air. The lowest air pressure rating is when the valve trips.

Every 3rd year on a dry system, we perform a full trip test.

We have to flow water to the end of the line and time it. A passing time is between 60-90 seconds.

We don’t perform full trip tests between the end of October through the beginning of April, due to the risk of freezing. We prefer to do these in the spring so the system has the entire summer to dry out.

And then everything that’s included in a wet system (full visual inspection, check for spacing, corrosion, etc.).

Other Fire Sprinkler Inspection Facts

  • Sprinkler heads must be replaced after 50 years on a standard sprinkler and 20 years on a quick response system which has different types of heads.
  • Inspections must be done every year (for both dry and wet).
  • Dry systems are a little more pricy because they require two technicians (one at the main valve, and one at the end of the line for the inspectors test).