Control valve for a water treatment system

A control valve for controlling the regeneration of a water treatment system, comprising:

• a) a control valve housing containing a control valve;
• b) a water usage meter assembly comprising a first metering disc overlying a second metering disc, wherein the first meter disc includes teeth on an outer perimeter thereof and an opening on an inner perimeter thereof, and the second meter disc includes teeth facing the inner perimeter of the first meter disc and a regeneration initiation cam slot on an outer perimeter thereof;
• c) a regeneration control disc for controlling a sequence of steps during regeneration;
• d) said first and second meter discs being relatively rotatable with respect to each other in order to provide incremental adjustments to a position of the regeneration initiation cam slot;
• e) said water usage meter assembly being advanced by a water flow responsive pawl mechanism that engages teeth on the first meter disc until the regeneration initiation cam slot on the second meter disc is aligned with a regeneration initiation cam follower whereupon a regeneration pawl mechanism is activated in order to produce rotation in said regeneration control disc;
• f) said regeneration control disc including at least one cam that operates to release an anti-rotation pawl from the teeth on the first metering disc and allow said water usage meter assembly to reverse rotate to a reset position, under predetermined operating conditions;
• g) wherein relative rotation between said first and second meter discs is resisted by a keeper pawl on the first metering disc that engages the teeth on the second metering disc;
• and
• h) an external adjustment member including a stem mounted to the housing and having a portion extending outside of said control valve housing and a portion comprising a pinion gear located inside the housing, wherein the stem is axially movable relative to the housing so that the pinion gear can be engaged and disengaged with the opening in the second meter disc and the teeth on the second meter disc, whereby upon engagement of said pinion gear with the opening on the first disc and the teeth on said second meter disc, the second meter disc can be rotated relative to the first meter disc after the resistance to relative rotation between the meter discs imposed by the keeper pawl has been overcome, and upon disengagement of said pinion gear from the teeth on the second meter disc, said keeper pawl operates to maintain the relative positions of said meter discs, so that said first and second meter discs rotate as a unit.