Fluid apparatus including gravity induced check valves and downwardly inclined lower lamella portion of a bellows

A fluid apparatus having a bellows, configured as a pump and placed in a pump body, said bellows being extendingly and contractingly deformable in an axial direction said axial direction defining a vertical axis, a liquid chamber formed inside said bellows, a suction port and a discharge port formed in an inner bottom face of said pump body facing said liquid chamber, said suction port and said discharge port communicating with an inflow passage and an outflow passage which are disposed in said pump body, respectively, and

• a suction ball type check valve and a discharge ball type check valve are disposed in said inflow passage and said outflow passage, respectively, wherein
• liquid is sucked from said suction port via said suction ball type check valve into said liquid chamber by extension of said bellows, and the liquid in said liquid chamber is discharged from said discharge port via said discharge ball type check valve by contraction of said bellows,
• each of said suction ball type check valve and said discharge ball type check valve is configured so that a cylindrical valve casing is disposed with setting an axis vertical, and a ball valve element is caused by own weight to be closely contacted with a valve seat in said valve casing, thereby preventing liquid from reversely flowing;
• and
• said discharge ball type check valve is disposed on a downstream end of said outflow passage.