An anti-free-flow mechanism includes an occluder mechanism which is disposed along a segment of tubing. The occluder mechanism is normally in a biased closed position, but may be moved into an open position by moving an engagement member into engagement with the tubing segment to deform the tubing segment and open a flow channel. Unless force is applied to keep the engagement member in contact with the tubing segment, the tubing will return to the first, closed position.
