A sterile liquid pump, having replaceable single use components, with a first and second chamber, and a gas valve assembly to selectively communicate gas pressure and vacuum with the chambers, and a resilient tubing liquid manifold loop with a sequence of four ports located within a manifold receiver that supports four pinch actuators aligned to engage and selectively pinch-off flow through the manifold between adjacent pairs ports, and, a controller that operates the valve assembly to alternatingly couple pressure and vacuum to the pump chambers, and that also operates to alternatingly actuate pairs of the pinch actuators to sequentially pump fluid from pump chambers under gas pressure, and through an opposing pair of ports in the resilient tubing manifold.