Abstract: There is provided a pinch valve system for controlling a fluid flow in a fluid flow path. The pinch valve system has an elastic sleeve member having a pair of outwardly extending elliptical folds on the circumference. The sleeve member is novel because the elliptical folds provide additional axial lengths that match the circumferential extension of the sleeve member when the sleeve member is in a pinched condition, thereby allowing the sleeve member always to be in a stress-free state. The sleeve member is novel because the inner surface is coated with a fluorocarbon material having superior chemical inertness and high operating temperature, thereby providing the elastic sleeve member with a long service life.