| 摘要 |
PURPOSE:To prevent change of elasticity of an elastic body under low temperature and enable to set the popping pressure as well as the blow-stop pressure of a valve correctly by a method wherein a valve rod, attached to a valve body opening and closing the port of a conduit for a low temperature fluid, is elongated while the elastic body such as a spring energizing the valve rod or the like is provided at a part having a normal temperature. CONSTITUTION:The space between a helium vessel (inner tank) 2 and the wall 1 of an outer tank is evacuated. A valve rod 3 is formed by connecting a cylindrical spring seat 4, a column-like washer 5 and a pipe 6, and is energized toward the downward direction thereof. A valve sheet 9 attached to the lower end of the pipe 6 opens and closes the port 10 of the conduit for helium. Since a spring 19 is provided at a part having a normal temperature, the change of elasticity of the spring 19 under an extreme low temperature may be prevented and the pushing force of the spring 19 upon a stationary time may be set correctly. |
