FRA Requires Retrofitting of Unapproved Tank Car Valves

The agency's March 13 order gives owners 60 days to replace any 3-inch McKenzie UNNR ball valve in a tank car used to transport any hazardous material described in 49 CFR 172.101 and 90 days to remove the 1-inch and 2-inch valves.

A recent Railworthiness Directive from the s Federal Railroad Administration orders railroad tank car owners to replace unapproved valves that are installed in some tank cars. They are UNNR ball valves manufactured and sold by McKenzie Valve & Machining LLC. FRA's announcement said its investigations showed the valves are not approved for use on railroad tank cars and that the 3-inch ball valve, when not properly configured, is causing tank cars to leak.

"The problem was first discovered when multiple FRA investigations identified several railroad tank cars leaking small quantities of hazardous materials. One instance occurred during the week of January 11th and involved a train of 100 tank cars loaded with crude oil being transported by BNSF Railway Company from Tioga, North Dakota, to a refinery in Anacortes, Washington," it stated. "BNSF discovered 14 tank cars leaking crude oil on the route. The FRA then inspected seven of the identified leaking tank cars that BNSF removed from the train in Vancouver, WA. The FRA inspector observed each of the tank car's top fittings and found product leaking from the liquid line ball valves and around each valve's closure plug. Further tests conducted by the FRA found that certain closure plugs installed on the 3" valves caused mechanical damage and led to the destruction of the valves' seal integrity. In addition, testing found that when a 3" closure plug was applied and tightened in the 3" McKenzie valve, the plug contacted and damaged the ball. Further testing revealed that the application of downward force on the valve ball applied by the 3" plug resulted in the over-compression, damage, and misalignment of the inboard seal, causing the valve to leak."

Additional tests concluded the McKenzie 1-inch and 2-inch ball valves do not appear to present the same safety concerns as the 3-inch valves, but they are not approved for use on railroad tank cars and so must be replaced. FRA as of March 13 was not aware of any non-accident releases or other releases from railroad tank cars involving the smaller valves. The agency also said if McKenzie can adequately demonstrate the safety of the 1-inch and 2-inch valves and obtains approval for the use of those valves on tank cars, cars equipped with them may be returned to hazmat service.