This document specifies testing procedures for evaluation of external leakage of valve stem seals (or shaft) of isolating valves and control valves intended for application in volatile air pollutants and hazardous fluids. End connection joints, body joints, vacuum application, effects of corrosion, and radiation are excluded from this document. This document concerns classification system and qualification procedures for type testing of valve stem sealing. This document is not intended to replace type testing of valve assemblies or valve production testing. Corrosion tests are not included in this document.