When it comes to underground services for your fire sprinkler system, you can’t afford to compromise. That’s why so many businesses trust Koorsen for the design and installation of their underground services. Our NICET certified experts develop solutions built around the unique needs of each customer. 

  • Fire Hydrant Installation
  • Post Indicator Valve (PIV) Installation
  • Fire Department Connection (FDC) Installation


Inspections and testing were the foundation of our business starting back in 1946 and continue to be one of our strongest services today. If your underground sprinkler system needs to be tested or inspected, trust the experts at Koorsen.   


Our team of certified technicians are known for their extensive knowledge and high level of service repairing and replacing fire hydrants, PIVs, and FDCs. Whether you need regularly scheduled maintenance or an urgent after-hours repair, our team is available 24/7 to handle any service issues you might face.

  • Fire Hydrant Repair & Replacement
  • PIV Repair & Replacement
  • FDC Repair & Replacement


Underground Services Installation, Repair, and Maintenance  Contact Us Now!

Underground FAQs

A post indicator valve (PIV\) is a raised post located outside a facility that connects to the main water line and controls the water supply to the fire sprinkler system. 

The FDC is an inlet and pipe system that allows a responding fire department to connect a hose line from their pumper truck to pump additional water into the fire sprinkler system to ensure sufficient water pressure to the sprinkler system.


Post Indicator Valve (PIV):

Usually located outside, the PIV is used to control the flow of water from the main underground water line to the sprinkler system.

Fire Department Connection (FDC):

A connection located outside a building, allow the responding fire department to pump water into the building’s sprinkler system.

Fire Hydrant:

A connection point where fire fighters can tap into the local water supply to aid in extinguishing a fire.

The Koorsen Difference



Family owned and operated for over 75 years.


Over 1,200 employees with locations in 25 cities across the Midwest and South.


NICET certified and factory trained. Fully insured and bonded.

Underground Services

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