An alignment system for accurately setting the flow rate of a flow selector device, the system includes a flow selector device having a flow rate selection mechanism rotatable between a plurality of pre-selected positions a knob providing a grip to rotate the flow rate selection mechanism, the knob having a distal portion, a proximal portion, and at least one registering element and a cover movable between an open position providing access to the knob and a closed position restricting access to the knob, the cover further including at least one cover element that prevents closure when the registering element is misaligned with a pre-selected position.
