sentences:  Ball valves, piston valves or gate valves could fail when in contact with aggressive products, due to body seat or the gate/piston wearing out too quickly.Air-operated pinch valves work with less wear of the elastic rubber hose because the kinetic energy of the solids are absorbed through the high elasticity of the rubber that also helps to resist abrasion.The sleeve material is selected among suitable synthetic polymer based upon the corrosiveness and abrasiveness of the flow media.