The development of Kelso's vacuum relief valve design has been driven by customers’ demand for a better performing VRV due to high failure rates of current products in the market. Kelso is dedicated to the development of best available safety technologies that deliver long term reliable high performance. Our new innovative VRV design features our patented constant force pressure springs and meets the new DOT-117 tank car specifications to be implemented on October 1, 2015. Kelso's VRV will be offered as 1.5, 3 or 4.5 psi with a 2.5 inch threaded connection or flange. The VRV commenced field service trials in summer 2015 and Kelso will announce as soon as the VRV is commercially available.