An example valve shaft apparatus includes a shaft having a stationary seal and a dynamic seal spaced from the stationary seal. The stationary seal defines a first leakage detection area adjacent the stationary seal and the dynamic seal defines a second leakage detection area adjacent the dynamic seal. A seal leakage detector is integrally formed with the shaft to provide a visual indication of process fluid leakage within the first leakage detection area or within the second leakage detection area. The seal leakage detector has a passageway in fluid communication with the first leakage detection area and the second leakage detection area. The passageway has a cross-sectional profile that changes between the first and second leakage detection areas to prevent fluid from flowing from one of the leakage detection areas into a body of the fluid valve.