Abstract: A fluid end assembly of a high pressure reciprocating pump includes a housing defining an interior bore, a first opening at a first end of the interior bore, and a shoulder that divides the interior bore into a plunger bore and an outer bore. A plurality of overhangs is formed as part of the housing and extends into the outer bore, a plunger is positioned within the space and is operable to reciprocate along an axis within the plunger bore, and a valve cover is coupled to the housing and positioned to engage the shoulder to close the first opening. A valve cover retainer is positioned within the outer bore and includes a plurality of projections arranged to selectively engage the plurality of overhangs to sandwich the valve cover retainer between the valve cover and the housing to lock the valve cover into engagement with the shoulder.