How Dry Sprinkler Systems Work
A dry sprinkler system is designed to protect areas that are, or may be, exposed to below freezing temperatures. Compressed air is pumped into the piping above the dry valve, which is a chambered mechanism that holds water back until a fire or leak triggers an air pressure loss. This loss of pressure will eventually go low enough to “trip” the system, pulling the clapper up and allowing water to flow into the system.
The Effects of Winter Weather on Dry Systems
It is vitally important that your dry system is properly maintained and serviced to ensure proper operation and avoid unwanted system trips. Over time, the regular small compressor top-offs to the overall pressure in the system will cause warm, moist air to collect inside the pipes. This can cause corrosion over the long term. This can also cause water to collect and freeze in trapped areas in the system. If water freezes in metal pipes, they can break very easily, causing a catastrophic loss of air pressure, flooding of the system with water, and water leaking out of the broken area(s).
To minimize the chance of this happening, building owners should perform (or have their fire sprinkler contractor perform) monthly or quarterly maintenance. All low points need to be drained—weekly or monthly— especially in the colder months and in the fall when cold weather is approaching. Many dry systems are equipped with drum drips, which isolate a small section of pipe so water can be drained off without shutting down the whole system.
Why It's a Must to Maintain Dry Systems
Another very important part of dry system care is air compressor maintenance. The tank (if equipped) of the compression needs to be checked/drained weekly or monthly to ensure that the entire tank capacity is available for stored air. Air compressors are required to be hard-wired per state code to minimize accidental shutoffs.
Finally, dry systems are required to be equipped with a “low-air” alarm signal, monitored by a 24-hour offsite monitoring company. If the low-air signal sounds, one should call their fire sprinkler contractor right away, as this usually means a system trip is imminent.
Knowing and performing these tasks are crucial to lengthening the life of your dry system, as well as avoiding the costs of water damage, building/work shut down, and repairs of the system.
Call our service technicians at The Fire Group, Inc. to schedule annual maintenance on your sprinkler systems at 1-888-701-3473.
By Steve Hinson, Jr.
Many business owners aren't aware that every five years, an internal inspection of fire sprinklers is required by Minnesota State Fire Code (MSFC) and National Fire Protection Association 25 (NFPA). Beyond the actual requirement, it is an important aspect of the regular inspection regimen of fire sprinklers.
The first part of a five-year internal inspection is to drain down the sprinkler system. The system is opened up in two places where the pipe can be accessed. From there, the pipe is visually inspected internally. The technician looks for any kind of foreign material that could indicate corrosion, microbiological contamination, or other inhibitors of proper sprinkler operation.
Overall, there are 14 conditions that we check for. When one of those conditions exists, we would begin what is called an "obstruction investigation". If no adverse conditions are found, the sprinkler system is put back into service on the inspection. It is rare upon a five-year internal inspection to find any issues requiring further investigation. However, it is vital to have this checked in order to keep up to code and keep your fire sprinkler system properly maintained. We can catch issues through this five-year internal inspection before it costs your business in unexpected damage in the future.
Our companies at The Fire Group, Inc. are equipped with experienced technicians and are able to inspect buildings throughout the state of Minnesota as well in Wisconsin, North Dakota and South Dakota. Contact one of our service managers at 218-821-9471 or email me (Steve Hinson) at email@example.com.
Steve Hinson, Jr. is a service manager at Fire Construction Services, LLC and has over seven years of experience working in fire protection.