Abstract: A pump adapted for use in desalination systems that has four cylinders, with a double acting piston in each cylinder. Each cylinder and piston thereby defines a feed chamber and a recovery chamber. The pistons are connected to a common drive. The connection to the common drive is such that the pistons reciprocate in a sequence equally spaced in time. Reciprocating valving for each piston is driven by the common drive to be 90 degrees out of phase with the respective piston. The valving connects the recovery chamber alternately to an inlet manifold for an intake stroke of the piston relative to the recovery chamber, and to an outlet manifold for a discharge stroke of the piston relative to the recovery chamber. There is a brief period of closure coinciding with top dead centre and bottom dead centre of the piston, during which the recovery chamber is blocked off from both the inlet and outlet manifolds.

Abstract: A pump in desalination systems has four cylinders, each having a double acting piston. Each cylinder and piston defines a feed chamber and a recovery chamber. The pistons connect to a common drive. The connection to the common drive is such that the pistons reciprocate in a sequence equally spaced in time. Reciprocating valving for each piston is driven by the common drive to be 90 degrees out of phase with the respective piston. The valving connects the recovery chamber alternately to an inlet manifold for an intake stroke of the piston relative to the recovery chamber, and to an outlet manifold for a discharge stroke of the piston relative to the recovery chamber. A brief period of closure coincides with top dead centre and bottom dead centre of the piston, during which the recovery chamber is blocked off from both the inlet and outlet manifolds. The reciprocating valving is midway between its top dead centre and bottom dead centre during the period of closure.

Abstract: An algae and bacteria contamination preventing apparatus and subsystem including a conduit forming a flush-water flow path between a potable water supply and a connection to a feed water entry port of a watermaker system. A check-valve and flush-water connector is installed in the feed water entry conduit. The flush-water flow path includes a valve means for opening and closing the flow path, a filter/ion-generator component a controller for sensing flush-water flow in the flow path, and in response thereto, applying electrical power to an ion-generating element of the filter/ion-generator component. The filter/ion-generator component also includes a filter element which removes undesirable chemicals from the potable flush-water before the ion-generating element introduces copper and/or silver ions into the flush-water. The valve means may be manually operated or be controlled by a watermaker system shut down controller.