Abstract: A ball-check type check valve is disclosed. A valve housing comprises a first vertically disposed cylindrical section and a second section which extends diagonally upwardly and away from the first section. A third housing section extends away from the second section at a lesser horizontal angle. When a fluid is caused to flow upward through the first housing section, the ball moves out of the first section, along the second section, and is held in an unstable condition in and on the third valve section. When fluid flow halts and pressure against the ball ceases, the ball rolls out of the third section, back down the second section, and into sealing engagement with the first section.