OPENING DISPLAY DEVICE FOR VALVE

PROBLEM TO BE SOLVED: To clearly display opening of a valve and to easily adjust the opening. SOLUTION: In a fitting part 73 of a first housing 7a, a cylindrical handle 63 is externally fitted. On a peripheral wall of the handle 63, observation holes 74 are provided at prescribed intervals in a peripheral direction. In a cylinder hole of the handle 63, a display tool 72 constituted of a transparent cylinder is fixed. On this display tool 72, a plurality of opening figures 76 of a prescribed color (black in this case) are described. Further, on an outer peripheral surface of the fitting part 73 of the first housing 7a, a first color area (white in this case) F allowing either one of the plurality of opening displays 76 to be visualized from the outside of the handle 63 and a second color area (black in this case) S preventing remaining opening figures 76 from being visualized are provided.