Abstract: A valve comprised of a valve body (1) incorporating a flow bore (2), of a check element (3) rotatably or pivotally adapted to said flow bore, said check element having the shape of rotational body or part of it, incorporating a flow port (4) and being supported by seat seals (5, 6), and of a driving stem (7). The stem is connected to the check element by means of a driver element (8) which is adapted to movably fit in a slot machined to the outside surface of the check element, said slot being aligned orthogonal to the longitudinal axis of the flow port of the check element. The driver element (8) is detachably joined to the stem (7). The end of the stem is adapted to a toothed, keyed or splined hole (12, 13) of the driver element (8) so as to render the joint a torque-transmitting capability.