Screwed piping connections can have unseen dangers due to the risk of crevice corrosion of the threads. Crevice corrosion of piping threads can result in a loss of strength and integrity along the threads. Leaking fittings should not be tightened under pressure as the connection may fail completely. It is important that all production operators maintenance crews and their supervisors are aware of the dangers of screwed piping fittings. Pressurised systems transferring corrosive gases are particularly dangerous.