What’s the difference between “labeled” and “listed” and what does it matter? Who or what are AHJ, NFPA, and UL?

These technical terms are used every day in the fire protection field, but they and many other bits of jargon can be confusing to homebuilders, designers, and others involved in home fire sprinkler installations. If you’ve been stumped by sprinkler techno-speak lately, this condensed layman’s glossary might help:

Authority Having Jurisdiction (AHJ) – The official person or office with responsibility for enforcing codes and approving equipment, materials, installation, etc.
Approved – Term used to indicate that equipment or materials are acceptable to an AHJ.
Backflow Valve – In some jurisdictions, code requires that the water flows through a special valve that isolates the sprinkler water to prevent cross-contamination with potable water.
CPVC – Chloro-polyvinyl chloride, or CPVC, is the orange plastic pipe frequently used in residential sprinkler installations. The lightweight, inexpensive material has helped bring down the cost of installing sprinkler systems in homes.
Extended Sprinkler – Home fire sprinklers cover a minimum area of 12 x 12 square feet. Extended sprinklers are designed to cover up to a 20 x 20 square foot area.
GPM – Gallons per minute. When activated by a fire, home fire sprinklers flow water at a rate of 10-26 gallons per minute. Fire department water hoses flow approximately 125 gallons per minute, under much greater pressure.
Labeled – Often describes equipment or materials that bear the label or mark of an organization that has tested and or certified it for a specific use.
Listed – Equipment, materials or services that meet certain standards or are suitable for specific uses are typically included in an evaluating organization’s publication, or “list”.
NFPA – The National Fire Protection Association is the nonprofit, international organization that publishes the National Fire Codes®, including NFPA 13D. While many products meet NFPA codes, NFPA does not test or approve products.
NFPA 13D – This is the short name for the Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes. The purpose of the standard is to provide “improved protection against injury, life loss, and property damage.”
Riser – This is the brains of the fire sprinkler system; it includes the water pressure gauge, flow switch, and the test and drain assembly. Where required or desired, a backflow valve and flow alarm would also be located here.
Trade Ups – Many AHJ’s now offer developers and homebuilders who install sprinklers flexible design and construction options that can save them money and increase density. (Learn more about valuable sprinkler trade ups on page 2 of SOLUTIONS.)
UL – Underwriters Laboratories Inc. UL has been testing fire sprinklers for more than 100 years and was the first to list residential sprinklers for installation in accordance with NFPA standards. UL tests, lists and certifies products, but “UL approved” is a misnomer. Learn more about UL recognition at www.ul.com/marks_labels.
Check Valve – This valve restricts water flow to one direction only.
Control Valve – This is what is used to turn the water flow on and off.

Sources: NFPA 13D, NFPA Automatic Sprinkler Systems Handbook, UL