The FM Approved UNITED Fire Systems Model AR-1 Air Vent for Wet Sprinklers is a device for automatically releasing the trapped air from the high point(s) of a wet sprinkler system.

Trapped air contains oxygen, which, when combined with water, is the primary cause of internal pipe corrosion. This corrosion can lead to pipe blockage, leaks, and pipe failure.

The Model AR-1 Air Vent is installed at the system high point(s). Air is vented until water reaches the internal float valve, which automatically closes the device to prevent water release.

To learn more about our Air Vent for Wet Sprinklers, give us a call at 908.688.0300 or contact UNITED Fire Systems online. 

Features & Benefits of Model AR-1 Wet-Pipe Fire Sprinkler System Air Vent

  • FM Approved – Complies with NFPA 13 component listing requirement.
  • Dielectric union – Prevents dissimilar metal corrosion
  • Ball valve – Allows AR-1 servicing without sprinkler system shutdown
  • Float valve – Automatic shutoff of the outlet when air is vented and water reaches the device
  • Strainer – Protects float valve from particulate matter that could contaminate valve seat
  • Outlet tubing connection – Provides optional connection for remote draining

NFPA 13 Requirements

The 2016 edition of NFPA 13, Standard for the Installation of Sprinkler Systems, requires a method to vent trapped air in all new wet pipe sprinkler systems. The language of this requirement is:

7.1.5 Air Venting – A single air vent with a connection conforming to 8.16.6 shall be provided on each wet pipe system utilizing metallic pipe. Venting from multiple points on each system shall not be required.

8.16.6 Air Venting – The vent required by 7.1.5 shall be located near a high point in the system to allow air to be removed from that portion of the system using one of the following methods: Manual valve, minimum 1/2″ size, Automatic air vent, or Other approved means.

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Contact UNITED Fire Systems Today

Give us a call at 908.688.0300 or contact us online to request more information about our Sprinkler Accessories.


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Did You Know?
  • Your dry-pipe or preaction fire sprinkler system can be infected! That’s right – microbes can be lurking inside your sprinkler pipes and causing damage.  Microbiologically influenced corrosion (MIC) occurs when the right combination of moisture and microbial organisms produces rapid corrosion of steel piping from the inside out. MIC is not the only cause of steel pipe corrosion, but it is important to know about and mitigate this problem BEFORE it causes pitting, pinholes, and thinning of pipe walls. Take steps to prevent both rust and MIC by using NITROGEN-PAC.