One of the biggest stories of 2010 involved valve failure. From April to July, engineers were scrambling to stop the hundreds of millions of gallons of crude oil being released into the Gulf of Mexico after the blowout preventer (BOP) on the Deepwater Horizon rig failed to seal the pipe. Of course, major disasters are typically preceded by known but uncorrected errors, and this was not the first time BP had trouble with isolation valves. As The Washington Post reported in June 2010, a 2001 operational integrity report covering BP’s North Slope operations found that, "Workers believe internal leak-through of isolation valves is a significant problem and under certain circumstances may pose a potential hazard to workers and equipment."
Such incidents attract a lot of attention, but most leaks are well-hidden somewhere deep inside the equipment and piping that cover the grounds of a power or petrochemical plant. These valves gradually eat away at performance and profits, a problem that is particularly critical with severe service isolation valves (SSIV). These issues, however, are preventable by using properly designed valves that allow zero leakage. The problem is that zero leakage does not always mean zero leakage. The usual definition actually means acceptably slow leakage internally, with no visible external leakage. But by applying the best available technology and adopting new standards, zero can equal zero, both internally and externally.