DEVICE FOR PREVENTING PRESSURE FLUCTUATION

PROBLEM TO BE SOLVED: To obtain a pressure fluctuation preventing device which has a flow path preventing slurry from being stagnated and also has corrosion resistance by providing an elastic tube, an operating member which presses down and deforms the elastic tube and a pressure mechanism that presses down the operating member with prescribed pressure. SOLUTION: This pressure fluctuation preventing device is connected into the circulation circuit of slurry with connection screw parts 12 and circulates the slurry. In such a case, prescribed air pressure is introduced into the pressure chambers 24 of upper and lower main body covers 21 from an electropneumatic proportional valve to press down a rubber plate 23 being an elastic plate, and the plate 23 presses and deforms the central cylindrical part of a flexible tube 10. A flow coefficient is reduced by reducing the cross-section area of the tube 10 due to this deformation, and the flow rate of the slurry is limited by increasing a flow resistance. Furthermore, the tube 10 is flexible and also is desirably manufactured with PTFE resin being excellent in durability and corrosion resistance as material in accordance with the pressure and quality of the slurry for polishing.