Valve shaft apparatus for use with rotary valve

An example valve shaft apparatus for use with a rotary valve disclosed herein includes a shaft having a first portion to be positioned in an opening of a valve body and a second portion to be positioned in a cavity of a closure member. A first seal is coupled to the first portion of the shaft to prevent fluid leakage into the opening of the valve body, where the first seal defines a first leakage detection area adjacent to the first seal. A second seal is coupled to the second portion to prevent fluid leakage into the cavity of the closure member, where the first seal is spaced from the second seal and the second seal is to define a second leakage detection area adjacent to the second seal. A passageway is formed in the shaft and fluidly coupled to the first and second leakage detection areas to provide an indication of fluid leakage past the first seal in the opening or to detect fluid leakage past the second seal in the cavity. The passageway is in fluid communication with a shaft outlet formed in an end of the shaft, where the shaft outlet is positioned away from the first and second leakage detection areas.