Abstract: The technical field of the invention is that of guillotine type valves for powdery, granular or pasty products.The technical problem posed consists in improving the valve disclosed in U.S. Pat. No. 4,356,838, so as to simplify the construction and maintenance thereof and to improve the operation thereof.According to the invention, the arms (7) of the plate (3) are removable, as well as the sleeve (23) force fitted into the external face of the orifice of the front and rear bodies of the valve. The internal face of each of the bodies (1, 2) is covered with a "duplex" seal (26) and the movable arms of the plate slide with respect to PTFE seals (16, 18). Finally, the abutment member (4) at the end of travel of the plate (3) is made retractable by means of a pneumatic or spring return device.