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.

A valve assembly positionable between open and closed positions in response to pressure differentials only comprising a valve chamber having an inlet and an outlet defined by a circumferentially extending tapered wall defining a valve seat adjacent the inlet and an outlet wall with at least one port adjacent this outlet. The assembly further comprises a valve element having a truncated frusto conical body portion and an outer peripheral tapered surface complementing the taper of the valve seat and a pad of smaller diameter than the largest diameter of the body portion depending from a large end of the body portion engageable with the outlet wall and displaced from the outlet port to permit flow from the inlet through the outlet when the valve is in the open position.

A check valve (22) is provided with a tapered plug (32), freely longitudinally movable with respect to a valve seat surface (34) disposed about the opening of the inlet passage (24). A plurality of cutouts (36) are disposed about the outer edge of the plug (32) for passing the forward flowing fluid. An exit nozzle (38) directs reverse flowing fluid against the rear of the plug (32), assisting valve closure.

An improved priming assembly which maybe used for siphoning, includes a siphon tube comprising an inlet end and a discharge end. The discharge end may be connected to a discharge hose that leads to a discharge area. A one-way valve is inserted within the tube adjacent to the inlet end of the tube. The valve comprises a flexible rubber sheath a portion of which is sealed to the inner surface of the tube and which extends toward the discharge end. The sheath is movable from an open position to a closed position. When fluid is caused to flow from the inlet end to the discharge end, the sheath moves to its open position allowing fluid flow. When fluid is caused to flow from the discharge end toward the inlet end, the sheath collapses to the closed position such that it prevents flow of fluid toward the inlet end. Priming of the siphon is created when the sheath collapses into its closed position, under the weight of the fluid as the rigid siphon tube is thrust upwardly. The sheath moves to the open position as the tube moves down within the fluid to be discharged, allowing fluid flow through the valve toward the discharge end, and to accumulate within the tube.

A sort of self-fill siphon pipe comprises a straight tube, a hose fitted onto the upper end of the straight tube and in communication with the straight tube, and a one-way valve fitted on the lower end of the straight tube wherein the one-way valve only allows the liquid to enter into the interior of the straight tube. In another form, there is provided inside the straight tube a tubular piston having a one-way valve slidable in the tube. The one-way valve on said tubular piston has a communication direction identical with that of the one-way valve at the lower end of the straight tube. While in use, the straight tube is inserted into the liquid and moves up and down intermittently, the liquid enters into the siphon pipe intermittently through the one-way valve and the siphon pipe is led into the siphon state to automatically suck the liquid.