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Defective CNG Cylinder Valve

November 2018 – Mankato, MN:  A manual cylinder valve manufactured by Luxfer failed while being opened, resulting in a gas leak, building evacuation, and finally an explosion when the leaking gas found an open ignition source in the heating system. 

This information is being provided as a courtesy of NGVi and does not replace in-depth training or constitute legal advice of any kind.

Incident Details NGVi Safety Note

November 2018 – Mankato, MN:  A manual cylinder valve manufactured by Luxfer failed while being opened by a technician resulted in a gas leak, personnel evacuation, and finally an explosion when the leaking gas found an open ignition source in the heating system.

The technician received minor injuries and was treated on site, and an employee who did not evacuate received 1st and 2nd degree burns and was treated at hospital.

In December 2018, NHTSA issued Safety Recall 18V-858 regarding Luxfer manual CNG cylinder valves installed on various models of trucks manufactured by McNeilus Truck & Manufacturing, Inc.  The complete notice may be found here.  

According to NHTSA, the safety risk is that the valve may separate under pressure, striking or injuring a person in the vicinity.  After separation, the valve will leak CNG fuel, which may result in a fire or explosion, resulting in further injuries and property damage.

Some types of CNG cylinder valves are designed to be opened and closed manually and some, like the Luxfer valve described in this bulletin, may feature a snap ring as a stop device.

Some valves may be harder to turn than others, and sometimes it is difficult to determine the valve position.

All technicians who are opening and closing manual valves must use caution not to overtighten valves in either direction (open or closed.)

If a valve appears to be stuck, tools should be used with extreme caution so as not to extend the valve past its stopping point.

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