To provide a hydrogen gas supply device with which pressure resistance of a filter that catches sulfur components contained in a hydrogen gas is improved. A hydrogen gas supply device for a hydrogen station includes a compression portion that compresses a hydrogen gas by reciprocating motion of a piston, in which a piston ring containing sulfur components is mounted on the piston, a filter arranged on the downstream side of the compression portion, the filter that catches sulfur components contained in the hydrogen gas, and a first pipe connecting the compression portion and the filter. The filter includes an element portion having activated carbon onto which the sulfur components contained in the hydrogen gas are absorbable, and a steel housing portion that houses the element portion, in which a gas introduction passage that communicates with the first pipe and guides the hydrogen gas to the element portion is formed.

A safety vacuum supply gas cylinder includes a cylinder body, a pipeline structure, first and second check valves (respectively having first and second check valve opening pressures P.sub.c1, P.sub.c2, wherein P.sub.c1 is greater than an atmospheric pressure P.sub.0). The cylinder body has an opening and an internal space configured to store a gas, wherein the gas forms an internal pressure P.sub.2 smaller than P.sub.0. The pipeline structure, communicated with the opening, has first and second pipelines where the first and second check valves are respectively arranged. An external filling gas enters the cylinder body when a pressure of the external filling gas is greater than P.sub.c1 and P.sub.2. The gas flows out when P.sub.2 is greater than P.sub.c2 and an external environmental pressure.

A system and method is disclosed for storing a fluid in a storage vessel in liquefied form and delivering it in gaseous form to an end user through a supply line. The system comprises a pressure relief circuit for returning the fluid from the supply line to the vessel when predetermined conditions are met. The pressure relief circuit comprises a return line connected to the supply line and the storage vessel, a diversion line to divert the fluid elsewhere and a switching device operable to direct the fluid to either one of the lines, as a function of predetermined conditions.

A system and method is disclosed for storing a fluid in a storage vessel in liquefied form and delivering it in gaseous form to an end user through a supply line. The system comprises a pressure relief circuit for returning the fluid from the supply line to the vessel when predetermined conditions are met. The pressure relief circuit comprises a return line connected to the supply line and the storage vessel, a diversion line to divert the fluid elsewhere and a switching device operable to direct the fluid to either one of the lines, as a function of predetermined conditions.

A system and method is disclosed for storing a fluid in a storage vessel in liquefied form and delivering it in gaseous form to an end user through a supply line. The system comprises a pressure relief circuit for returning the fluid from the supply line to the vessel when predetermined conditions are met. The pressure relief circuit comprises a return line connected to the supply line and the storage vessel, a diversion line to divert the fluid elsewhere and a switching device operable to direct the fluid to either one of the lines, as a function of predetermined conditions.

A safety vacuum supply gas cylinder includes a cylinder body, a pipeline structure, first and second check valves (respectively having first and second check valve opening pressures P.sub.c1, P.sub.c2, wherein P.sub.c1 is greater than an atmospheric pressure P.sub.0). The cylinder body has an opening and an internal space configured to store a gas, wherein the gas forms an internal pressure P.sub.2 smaller than P.sub.0. The pipeline structure, communicated with the opening, has first and second pipelines where the first and second check valves are respectively arranged. An external filling gas enters the cylinder body when a pressure of the external filling gas is greater than P.sub.c1 and P.sub.2. The gas flows out when P.sub.2 is greater than P.sub.c2 and an external environmental pressure.