Circle Seal Controls is recalling 67,416 pressure relief valves used in compressed natural gas and bi-fuel CNG vehicle fuel tanks, the National Highway Traffic Safety Administration reports.
Circle Seal Controls is part of CIRCOR Aerospace Inc.
The pressure relief valves, used in compressed natural gas and bi-fuel vehicle fuel tanks, have O-rings that can fail and allow fuel to leak.
Circle Seal Controls is recalling 67,416 pressure relief valves used in compressed natural gas and bi-fuel CNG vehicle fuel tanks, the National Highway Traffic Safety Administration reports.
Circle Seal Controls is part of CIRCOR Aerospace Inc.
The valves have O-rings that could fail after exposure to cold temperatures, allowing natural gas to leak from the fuel tank and pose a fire risk, NHTSA said. The valve model numbers are 8100-11-T1T1, 8100-37-BB, 8100-44-BB, 8100-77-BB, 8100-84-BB, 8100-94-BB, and 8100-97-BB. They were manufactured from July 2011 through December 2013.
Circle Seal will notify the CNG tank manufacturers of the defect.
To resolve the issue, bi-fuel vehicles with the defective valves will receive replacement valves free of charge. Replacement valves will also be installed in affected CNG vehicles either sold in or registered in the following cold-weather states: Alaska, Colorado, Connecticut, Idaho, Iowa, Illinois, Indiana, Massachusetts, Maine, Michigan, Minnesota, Montana, Nebraska, New Hampshire, New York, New Jersey, North Dakota, Ohio, Pennsylvania, Rhode Island, South Dakota, Utah, Vermont, Wisconsin and Wyoming.
The replacement valves are expected to become available in the fall of this year. Vehicle owners will receive two recall notifications – one this month and another when parts are available for installation.
Vehicle owners can reach Circle Seal Controls/CIRCOR Aerospace at 1-951-270-6317.

Distracted driving remains one of the most persistent risks in fleet operations. New approaches focus on removing mobile device use entirely while adding real-time safety support.
Read More →
As distraction risks evolve, fleets are turning to smarter, more connected technologies to better understand what’s happening behind the wheel. Part 2 explores how these tools are helping identify risky behaviors and improve visibility across operations.
Read More →
What fleets capture to improve safety can also expose them in litigation, forcing leaders to rethink how data is managed, stored, and shared.
Read More →
Distracted driving is often measured by what we can see—phones in hand, eyes off the road. But what about the distractions we can’t? A recent incident raises a bigger question about awareness, attention, and why subtle risks so often go unnoticed.
Read More →
While serious crashes are declining, a rise in minor incidents and ongoing risk hotspots underscore the need for continued fleet safety investment.
Read More →
Fleets have more driver data than ever, so why isn't behavior changing? Training requires more than reports and coaching — it requires real-world practice.
Read More →
A two-part conversation with Stefan Heck on how AI is transforming the fight against distracted driving. As fleets adopt smarter tools, the focus shifts from reacting to preventing risk. In Part 1, we look at where AI is making an impact for fleets today.
Read More →
More people on foot means more risk for drivers. These pedestrian safety tips can help prevent serious injuries and keep everyone safer on the road.
Read More →
Safer crews. Fewer incidents. Better uptime. Learn how driver-assist technology is changing the way vocational fleets operate.
Read More →
An 11% drop in pedestrian fatalities in early 2025 signals progress in U.S. road safety, but elevated death rates and ongoing risks underscore the need for continued action from fleets and policymakers.
Read More →