Multiway wave

What is provided is a flow shut-off element, particularly for use in the medical field of peritoneal dialysis, consisting of a valve body (2) having an inner cavity (3) and a plurality of accesses (4, 5, 6); a selector having a projecting portion inserted into the inner cavity of the valve body and movable relatively to the latter into a predetermined number of operating positions to create predetermined paths in which the fluid flow is permitted and/or shut off between the said accesses. Also provided is an auxiliary element interposed in a removable way between the valve body and the selector, this element having positioning means to enable an operator to determine when one of the said predetermined operating positions of the selector has been reached.