/community-hubs/valves-actuators-regulators/b/vcp-weblog/posts/isolate-and-protect-in-hydrogen-dispensing-maintenance-operationsDouble block and bleed valves enable maintenance on a section of process piping. They allow plant staff to block off and depressurize the section that requires maintenance. They consist of two block valves and one bleed valve. One of the valves blocksen-USTelligent Community 13