The present invention relates to a device for the storage and delivery of liquid and/or gaseous media under pressure, having a media container (1) of a plastics material, preferably of polyamide, receiving the medium, at least one valve connection element (2), connected to the media container (1), and at least one valve element (3, 3a, 3b), connectable to the valve connection element (2), wherein the media container (1) has a collar (4), which is molded on in one piece and protrudes from the media container (1) and has a collar outer wall (5) and a collar inner wall (6). A restoring element (11, 11a, 11b) is arranged in such a way that, during the fitting of the valve element (3, 3a), the collar (4) and the restoring element (11, 11a, 11b) are jointly pressed between a partial region (9a) of the wall (9) and the pressing portion (10), wherein the restoring element (11, 11a, 11b) is formed from a crosslinked plastics material, preferably from crosslinked polyethylene, and wherein the pressing portion (10), the collar (4) and the restoring element (11, 11a, 11b) are made to match one another and formed in such a way that the joint pressing of the collar (4) and the restoring element (11, 11a, 11b) has the effect that an elastic deformation (X) of the restoring element (11, 11a, 11b) that is greater than the maximum creep deformation (Y) of the collar (4) over the service life of the device can be set, and so the creep deformation (Y) of the collar (4) can be compensated by way of the restoring element (11, 11a, 11b). The invention also relates to a fuel-energy conversion device, a motor vehicle and a method for fitting a device for the storage and delivery of liquid and/or gaseous media under pressure.

There is disclosed a fuel tank valve assembly 24 for a fuel tank 4. The fuel tank valve assembly comprises a discharge valve 30 which in normal operation is closed, and which can be opened to discharge fluid from the fuel tank; and a water passageway 56 across which extends a membrane 60 which is permeable to water but impermeable to fuel. There is also disclosed a fuel tank 4 comprising a fuel tank valve assembly 24.