This is a ram type reciprocating piston pump that is driven by a separate electrically powered hydraulic power unit. 

The pump and hydraulic power unit form a single integrated pump set. 

The pump is of robust, heavy3duty design and construction with an anticipated working life well in excess of 20 years. The pump body and the valve boxes are one piece steel fabrications. The sludge ram is manufactured from stainless steel. The sludge seals are maintenance free chevron rings, which are replaceable as a service item without the removal of the sludge ram. 

The hydraulic cylinder driving the sludge ram is built to off shore specifications and is of a hardwearing design featuring a chrome piston rod. 

The hydraulic cylinder also features extensive internal guidance and support for the piston rod thereby eliminating lateral forces upon the hydraulic seals, which can promote oil leaks. The top of the hydraulic cylinder features internal, hydraulic cushioning to facilitate absolute control over the sludge ram at the top of the stroke where the ram changes direction from up to down. This  contributes to the quite operation of the pump. 

This hydraulic unit comprises a hydraulic oil tank beneath which sits an electric motor driving through a bell housing and coupling to a variable speed, pressure compensated hydraulic oil pump.