A fluid end for a duplex mud pump. In one implementation, the fluid end includes two liner blocks, each having a central passage. The fluid end further includes two fluid inlets disposed on a side portion and two fluid outlets disposed on a top portion and a suction manifold displaced from the two liner blocks. The suction manifold comprises four flanges. The fluid end further includes four suction valve blocks, each having a bottom portion removably coupled to one of the four flanges and a side portion removably coupled to the side portion of the liner block, and four discharge valve blocks, each having a bottom portion removably coupled to the top portion of the liner block.