Abstract: In a gas valve including a valve body having an annular seal surface, of which an axis is disposed to extend in a vertical direction, and of which seal surface a diameter becomes larger toward a lower end of the seal surface, to prevent water drops on the seal surface made by condensation from freezing and to prevent the seal surface from being fixed to a seat because of the freezing, a liquid repellent film is provided on the seal surface of the valve body.

Abstract: A high-pressure tank in which the sealing ability and pressure-proof strength at a mouth portion are prevented from being lower by a high pressure within the tank, wherein the mouth portion 2 projects into the inside of the tank, and internal threads are formed on an inner peripheral surface of the mouth portion, and a thread member is threadedly engaged with the internal threads. Further, a seal member is provided between the mouth portion and the thread portion, and is disposed adjacent to the inner peripheral surface of the mouth portion adjacent to an inner end thereof disposed within the tank. A high pressure within the tank acts on an outer peripheral surface of the mouth portion while the atmospheric pressure acts on the inner peripheral surface of the mouth portion, so that the mouth portion is compressed radially inwardly, thereby preventing the loosening of the tightened seal member.

Abstract: In a gas valve including a valve body having an annular seal surface, of which an axis is disposed to extend in a vertical direction, and of which seal surface a diameter becomes larger toward a lower end of the seal surface, to prevent water drops on the seal surface made by condensation from freezing and to prevent the seal surface from being fixed to a seat because of the freezing, a liquid repellent film is provided on the seal surface of the valve body.