Abstract: A pump assembly for serial connection along a primary fluid line includes a pump and a pump bypass. The pump has an inlet side and an outlet side, and is configured to receive a first fluid from the inlet side, and expel the first fluid from the outlet side. The pump bypass is actuatable between first and second valve states. The first valve state fluidly connects the pump in series along the primary fluid line, and connects an input side of the primary fluid line to an output side of the primary fluid line only via the pump. The second valve state fluidly isolates the pump from the primary fluid line, and fluidly connects the input and output sides of the primary fluid line via a continuously piggable path.