| 摘要 |
An antitampering and safety ball valve ( 1 ) in which, in the cylindrical seat ( 22 ) of the handle ( 20 ), for example of squared shape ( 20 ), for housing the nut to be threaded on the rod ( 8 ) for fixing the handle ( 20 ) on the valve ( 1 ), a nut ( 31 ) having an odd side number, preferably with a heptagonal shape, is used. A tubular wrench ( 33 ) with a recessed seat ( 34 ), having likewise a polygonal configuration with an odd number of sides and which can be housed, preferably with a small clearance, in the cylindrical seat ( 22 ) of the handle ( 20 ) being moreover provided.
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