Kelso Technologies Inc. filed a patent application for a new externally mounted dual rating pressure relief valve (DPRV) design for use on new rail tank cars and retrofits of existing rail tank cars. Kelso has initiated a proactive design strategy based on the regulatory concerns and as a result created a new DPRV design that based on mechanical engineering innovations that provide safety benefits in both accident and non-accident environments. In general terms in an accident involving fire the DPRV will significantly lower its operating pressure rating to a level that will keep the valve open in order to evacuate the tank car in less than 100 minutes as required by AAR recommendations.

This is a dramatic change to current technology capability. In addition, Kelso believes the DPRV will provide economic advantages to the impact of the expense of retrofits facing the railroad industry. The patent has been filed under a Non-Publication Request which keeps the patent filing private until the patent is issued.

The final patent will likely take 2 years or more to be granted and carry a 17 year life starting from the date the patent is granted. The DPRV will enter Association of American Railroads (AAR) approval process shortly after the prototypes are completed in May 2014.