Abstract: A check valve is disclosed for permitting a fluid flow in a generally one direction. The check valve is provided with an elongated housing with a central passageway within which a valve member moves for permitting a fluid flow in one direction and for closing a fluid communication when moving in an opposite direction. The valve member has a conically-shaped groove for receiving a sealing member therein. When the sealing member becomes expanded under the influence of fluids passing through the check valve, it is allowed to move from the groove along a neck of the valve member. The interior wall housing is provided with plurality of longitudinal grooves extending in parallel relationship to a central axis of the housing in that part of the housing wherein the valve member moves. The longitudinal grooves ensure fluid flow through the valve member at all times.