| 摘要 |
PURPOSE:To prevent grease from sticking to a spherical valve and to avoid an occurrence of an unsatisfactory performance by deppressing the spherical valve of an overflow prevention valve to return to the initial position at the place apart from the grease coated section on the sliding faces of a plug and a cock main body. CONSTITUTION:When an overflow condition occurs with a plug 1 at a fully opened position, a spherical valve 3 is raised in a cylindrical body 5 and is inserted into a valve seat port 4 to cut off a gas passage 7. Under this closed valve condition, a part of the spherical valve protrudes outside the cylindrical body 5 through the valve seat port 4, and when the plug 1 is rotated to a close position, the spherical valve 3 is deppressed by means of a protrusion 14 provided on the inner peripheral wall of a vacant chamber 2 of the plug 1, returning to the initial condition. During this reset operation, the portion which the spherical valve 3 gets into contact with is a part of the inner periphery of a passage hole of the plug 1, thereby the grease coated on the sliding faces of the plug 1 and a cock main body 6 will not stick to the spherical valve 3 and an occurrence of an unsatisfactory performance can be prevented. |
