Dunn’s Valve Testers (DVT) has been the leader in manufacturing and maintaining valve testers since 1978. DVT was the first to introduce these machines and we continue to innovate as a partner with our customers. Each machine is built to provide maximum uptime with the shortest cycle time for your operations. Safety Relief Valve Testers, Control Valve Testers, Flange Clamp Testers, Roll Frame Testers, Vertical and Horizontal Clamp Testers.