Abstract: A check valve assembly is disclosed wherein a valve closure means includes a guide means and a connector means as a composite member for use in a pipline or conduit inclined to the vertical. The mass of the composite member relative to the angle of inclination and the coefficient of friction between the internal surface of the valve body and the external surface of the guide means is such that there is no risk of valve "jamming" action which would block operation of the valve. In addition the guide means ensures symmetrical fluid flow whereby the valve operates positively and rapidly eliminating chatter and erratic travel during the course of opening and closing when fluid flow is reversed.