Abstract: A tie rod type cylinder valved at its lower plate and having a receiver on its upper plate. A rod-less trunk-like piston containing an inlet valve with a stem projecting out of the cylinder and connected with an actuator. The piston face having an opening acting as a valve seat. A capillary vent tube connecting the top of the cylinder with the mouth of the receiver. When the cylinder is filled to a stop, the actuator is activated, which closes the inlet valve and drives down the stem/valve/piston and it evacuates the cylinder. A flexible discharge line conveys the liquid into a nearby drain pipe or receptacle.

Abstract: Two flanged sleeves, closed and valved at one end, and a bonnet with two gudgeons act as a cylinder-piston mechanism for pumping. The upper sleeve is movable and spring-loaded, accepts and is filled with liquid. When the bonnet is depressed, through its gudgeons, upper valve is closed, upper sleeve is pushed down, lower valve is constrained open, and the content is pumped into a discharge.