to measure the pressure in the respective transfer conduits a pressure relief valve 228 and associated pressure sensor transmitter 216 may be connected to conduit 235 the pressure relief valve 228 may be set to relieve gas at any desired pressure for example a pressure ranging from 46 mpa to 50 mpa a block valve is any valve that is capable of blocking the flow in both directions any suitable block valve known in the art of hydrogen fueling may be used a bleed valve is any device that is capable of bleeding off a gas from the conduit to vent the conduit any suitable bleed valve known in the art of hydrogen fueling may be used the hydrogen dispensing unit comprises a controller 120 operatively connected to the control valve 104 the various block valves bleed valves and pressure sensors the controller may be a computer process logic controller plc or the like controllers are ubiquitous in the art of hydrogen dispensing the controller 120 may receive signals from the pressure sensors 107 116 238 and 216 and send control signals to the block valves 108 208 and 226 and bleed valves 114 and 214 hydrogen fueled vehicles comprise a receiving tank 118 or 218 and a.