In the wet-end section of a paper machine, this air-operated diaphragm pump with integrated speed reducer sits between the broke chest and the broke pulper. Its role is to meter thick stock—consisting of repulped broke, fiber clumps, and residual water—from the chest to the pulper at a controlled, low flow rate. The speed reducer ensures the pump delivers a steady, gentle stream rather than a surge, preventing fiber flocculation and allowing the pulper’s rotor to break down the material evenly. Operators adjust the air pressure to match the stock’s consistency, typically running the pump continuously during broke repulping cycles. Because the diaphragm isolates the pumped medium from the drive mechanism, the pump handles abrasive slurries without internal wear, reducing maintenance in the high-moisture, high-fiber environment of the wet end. A secondary use appears in coating preparation lines, where the same pump transfers pigment slurries to the coater head at a precise rate, ensuring uniform coating weight across the paper web.