Operating an Oil refinery today means searching for methods to reduce risk to personnel and plant equipment.  There are so many deterioration processes active on refinery equipment / piping etc. But this paper will concentrate on material selection and operational control issues related to “Wet H2S Cracking” in refinery process environment. This paper will also address operational control like wash water injection, corrosion inhibitor dosing and APS dosing for substantial reduction of   “Wet H2S” related damages in operating equipment / piping. Inspection methods (WFMT etc)  & its priorities, intervals and extent of inspection are also covered in the papers.