摘要 |
<p>A dual-unit pump, e.g., a rolling diaphragm piston pump, suitable for pumping an abrasive high-viscosity slurry, is adapted to operate at a constant flow rate by means for detecting and correcting a pressure differential in the two units before the units switch from the pumping cycle to the filling cycle and vice versa. The flow of liquids is controlled by valves of the type which switch the flow to and from the units with essentially no volume change in the liquid inlet and outlet lines.</p> |