Dual-Rated PRV

On February 20, 2014 Kelso announced that it had filed a patent application for its new dual-rated pressure relief valve (DPRV) design based on existing patents that cover our external constant-force spring PRV.  The DPRV was developed in response to an industry-wide request by the Association of American Railroads and the Railway Supply Institute for higher performance standards for pressure relief valves used on rail tank cars carrying crude oil, ethanol and other packing group I and II commodities or those requiring higher start to discharge pressures.  This is a key part of ongoing regulatory efforts by the United States and Canada to provide safer rail tank cars.  In general terms, in a rail tank car accident involving fire, our DPRV will significantly lower its operating pressure rating based on temperature only to a level that will keep the valve open in order to evacuate the contents of a tank car in less than 100 minutes as specified by AAR recommendations.  Our DPRV fits seamlessly to existing tank car designs and can be retrofitted in the field to minimize costs.