POURING PLUG

摘要

PROBLEM TO BE SOLVED: To provide a pouring plug capable of preventing an O-ring from being dropped during its disassembly and washing operations and concurrently capable of improving a replacing work characteristic of the O-ring at the time of maintenance and inspection. SOLUTION: A step portion 41 is formed coaxially inside a flow axis direction from a circumferential edge in a flow passage of a connecting end of a valve main body 18 to a valve coupler 15. A rib 42 is extended outside a flow axis direction from a circumferential edge inside a radial direction of the step portion 41 and there is formed an O-ring fixing groove 43 into which an O-ring 17 is inserted. Then, a height size H1 of the rib 42 of the O-ring fixing groove 43 is formed to be slightly smaller than a size of a radius R in a wire diameter of the O-ring 17. A width size W1 of the rib 42 is formed to become substantially equal to a length size of a cord in an axial sectional surface of the O-ring 17 at a position of the height size H1 of the rib 42 from a top point of the axial sectional surface of the O-ring 17.