Hi,
We experienced a control valve packing external leak on gas service, after valve disassembly we found some damage on the stem surface. Crevice corrosion of the chrome plated 316 SS base material stem was identified as the damage mechanism. The damaged stem was replaced in kind and a visual valve inspection survey was implemented for this type of valves and based on the findings it is expected to have external packing leak again, so we worked along with the valve manufacturer and the use of a new stem material was recommended. However due to delivery time issues and as a back up plan in case spare unavailability I wonder if there is any recommended practice to repair the stem corroded area.
Please refer to the attachment file to see the type of damage.
We experienced a control valve packing external leak on gas service, after valve disassembly we found some damage on the stem surface. Crevice corrosion of the chrome plated 316 SS base material stem was identified as the damage mechanism. The damaged stem was replaced in kind and a visual valve inspection survey was implemented for this type of valves and based on the findings it is expected to have external packing leak again, so we worked along with the valve manufacturer and the use of a new stem material was recommended. However due to delivery time issues and as a back up plan in case spare unavailability I wonder if there is any recommended practice to repair the stem corroded area.
Please refer to the attachment file to see the type of damage.
