US Patent 9863583 Method of operating a hydrogen dispensing unit

Method of operating a hydrogen dispensing where pressure relief is provided through block and bleed valves. After dispensing hydrogen from a dispensing station where the hydrogen is cooled during dispensing, trapped hydrogen remains in the transfer lines. During the idle time between refueling vehicles, the temperature of the trapped hydrogen increases resulting in an increase in the pressure of the trapped hydrogen. Block and bleed valves operate to relieve the pressure in the transfer lines.