Why chromium plated ball valves may not be acceptable in a refining environment?
I have come across a guideline which just states that chromium plated balls are not accptable. It does not state any specific services just the general instruction to not use.
Nothing on alternative types of plating either.
Chrome is a brittle coating material that does not fully cover the base material.  It contains numerous cracks that extend down to the base metal.  So it is not acceptable for corrosion protection.  It is great for wear.  For corrosion protection, it is common to apply a layer of Nickel underneath the chrome for corrosion protection with a layer of Chrome on top for wear resistance.
For Kerosene, chrome on top of 317 is good.  But other areas in refineries deal with various corrosive media so in general, you need to be careful in case someone puts a Chrome plated ball in an application that will corrode the base metal.

MORE NEWS