US Patent 7828012 Port integrated within valve stem

A valve body defines a fluid passage and a valve sealing body is positioned there. The valve sealing body is operable between open and closed positions which allow for fluid-flow and non-flow, respectively. The valve stem has a free end and an engagement end where the engagement end engages the valve sealing body so that rotation of the valve stem operates the valve sealing body between the open and closed positions. A measurement passage is defined through the valve stem from the free end to the engagement end. The measurement passage is in fluid communication with the fluid passage when the valve sealing body is in the open position, and at least one sealing member is positioned within the measurement passage.