Patent ID: 7779865

Claim:
A plumbing control valve comprising: a rotational control disk having a facing surface; and a fixed control disk having at least one through hole, a facing surface of the fixed control disk contacting the facing surface of the rotational control disk when the rotational control disk is rotated to control flow through the control valve; wherein the facing surface of the fixed control disk is formed with a raised contact surface that undulates in a radial fashion; wherein the plumbing control valve is selected from the group consisting of volume control valves, mixing valves, and water distribution valves; wherein there is a first raised undulating ring adjacent a central portion of the facing surface of the fixed control disk, there is also a second raised undulating ring adjacent a radial periphery of the fixed control disk and around the first raised ring, and the first and second raised undulating rings are interconnected by at least one raised spoke.