Pressure reducing device

1 . A pressure reducing device comprising an upstream end configured to be connected to a pressurized gas source and a downstream end configured to be connected to a coupled installation and comprising:

an operational fluid circuit comprising a pressure reducing unit configured to reduce a pressure of a pressurized gas flow to a maximum pressure P A , an emergency shut-off valve and an outlet interface with a pressure capability P N , a relief fluid circuit comprising a first end connected to the operational fluid circuit downstream of the pressure reducing unit and a safety relief device,

the relief fluid circuit comprising a second end connected to the emergency shutoff valve, and that the safety relief device is configured to have at least two states, a closed state where the safety relief device is inactive and the emergency shutoff valve is open, when the pressure in the fluid circuit downstream of the pressure reducing unit is lower than a predetermined pressure P L , and an open state where the safety relief device is active and the emergency shutoff valve is closed, when the pressure in the fluid circuit downstream of the pressure reducing unit is higher than the predetermined pressure P L ,

the predetermined pressure P L being between P A +5% and P A +500% and/or between P N +5% and P N +500% wherein the operational fluid circuit comprises a residual pressure valve and/or a non-return valve, further comprising a bleeding valve,

wherein a central part of the residual pressure valve comprises a second piston, and in that a middle chamber is delimited by a first piston and the second piston, and that in the open position of the safety relief device, the bleeding valve is moved in a closed position by the second piston.

2 . The pressure reducing device according to claim 1 , wherein the operational fluid circuit comprises a main shutoff valve.

3 . The pressure reducing device according to claim 1 , wherein the emergency shutoff valve is placed downstream of the pressure reducing unit.

4 . The pressure reducing device according to claim 1 , further comprising the residual pressure valve, wherein the residual pressure valve is the emergency shutoff valve.

5 . The pressure reducing device according to claim 4 , wherein the non-return valve is comprised in the emergency shutoff valve.

6 . The pressure reducing device according to claim 1 , wherein the safety relief device comprises a bursting disc.

7 . The pressure reducing device according to claim 1 , wherein the safety relief device comprises a safety relief valve.

8 . The pressure reducing device according to claim 1 , wherein the safety relief device and the emergency shutoff valve are connected through a fluid connection, said fluid connection comprising a reset valve.

9 . The pressure reducing device according to claim 1 , wherein the pressure reducing device is a one-way valve.

10 . The pressure reducing device according to claim 1 , wherein the relief fluid circuit comprises the bleeding valve.

11 . The pressure reducing device according to claim 1 , wherein the relief fluid circuit comprises a flap leaning against the bleeding valve.

12 . The pressure reducing device according to claim 1 , wherein the central part of the residual pressure valve comprises the first piston being mobile in the middle chamber, and in that the residual pressure valve has three connections:

an entry connection fluidly connecting a pressure reducing unit outlet to the residual pressure valve,

a first connection fluidly connecting a residual pressure valve outlet to the safety relief device and

a second connection fluidly connecting a safety relief device outlet to the middle chamber of the residual pressure valve,

and that in an open position of the safety relief device, the outlet interface is moved in a closed state by the first piston.

13 . A device for storing and supplying compressed gas comprising a fluid source and a pressure reducing device according to claim 1 .