Kelso's pressure relief valve raises the bar on best available technology from railway equipment suppliers. Our external PRV design for general purpose tank cars improves reliability and performance over the older internal models that allowed active components to come in contact with the commodities being transported. In addition, the maintenance requirements for the Kelso PRV are less frequent due to elimination of contact with the goods inside the car, and the inspection process each time the tank car is loaded is far less time-consuming due to the Kelso PRVs location outside the car.  With thousands of units in service the Kelso external PRV has demonstrated reliable operations in many tough service conditions without need of maintenance or unscheduled repair.