In some processes, there is ALWAYS a need to “leak test” before returning a segment of piping to service. These “leak test” pressures are done at NORMAL Operating pressures using a calibrated solution such as SNOOP. And every once in a while, I get a question about doing a “leak test” at some really low pressures. I do not usually allow these lower pressures on most hazardous materials piping, but on some low-hazard piping, I will consider them. However, there are LIMITATIONS on this leak testing process. For example…