US Patent 11293563 Control valve

The invention relates to a control valve for adjusting a process fluid flow of a process plant, comprising a valve housing with a valve seat and a valve member connected to a valve rod, which cooperates with the valve seat for opening and closing the control valve, wherein the valve rod is electrically connected to the valve housing through a contact device. The invention is characterized in that a measuring device for the ohmic transition resistance measurement of the contact device is provided, and that the measuring device is arranged in a measuring line that connects the valve housing to the valve rod.