In fluid flow measurement applications, apparatus and associated systems, computer program products, and methods may include a positive displacement fluid flow meter having an actuator to control fluid flow through the meter, and further having two or more rotating members with substantially parallel axes that rotate in response to the actuator and to fluid flow through the meter. In various implementations, the actuator may promote and/or retard a fluid flow being measured through the meter. In some examples, the fluid flow meter may operate as a pump to controllably increase a line pressure, controllably regulate a fluid flow rate by opposing rotation of the rotating members, substantially stop a fluid flow, and/or reverse a base fluid flow direction. In an illustrative example, the meter may operate to accurately monitor and control fluid flow (e.g., fluid pressure, velocity, and/or volume) before, during, and/or after a line break.