| 摘要 |
There is disclosed an improved internal pressure relief valve for filling a cryogenic liquid storage tank. The internal pressure relief valve consists of a housing with a sealing seat at one end, an inlet hole at the other end, and a ball enclosed therein. The internal pressure relief valve is constructed of materials which can withstand the heat encountered during fabrication without melting. Consequently, the material for the ball is more dense than the cryogenic liquid in the tank so that the ball will not float in the cryogenic liquid. Consequently, the ball and the housing are dimensioned so that the momentum of the cryogenic liquid as it flows into the housing toward a vent port during the filling operation is sufficient to drive the ball into engagement with the sealing seat, closing the vent port, and assuring the termination of the filling process when the pressure in the cryogenic tank builds up to that of the delivery pressure. |
