EE was working under a piping flange and as he stood up he struck his hardhat on the piping flange jamming his neck. There was a mound of scale build up creating an elevation change. The EE claims that the scale buildup is what caused him to strike his head on the piping flange. EE on restricted duty from 12/22/2011 to 01/03/2012. EE RTW full duty on 01/02/2012.