Abstract: A gate valve for use with a catheter including an elongated valve body having a transversely extending slide chamber and a slide member slidably supported in the slide chamber for transverse sliding movement between first and second positions. The slide chamber is defined in part by a pair of longitudinally spaced valve surfaces having longitudinally aligned inlet and outlet ports with the slide member having an enlarged opening extending therethrough also in a direction longitudinally of the valve body. A resilient insert element is carried within the opening in the slide member and is longitudinally moveable and self-adjustable therein with a longitudinal dimension in an uncompressed state greater than the distance between the valve surfaces of the slide chamber.