Method and apparatus for detecting leaks in a gas pipe line

摘要

A method and apparatus for measuring a gas pressure gradient in each of the upstream and downstream parts of a gas pipe line and detecting a leak in the gas pipe line in accordance with the pressure gradients. When a gas leak occurs, the gas pressure at the position of the leak is decreased and at least the pressure gradient upstream of this position is increased. When the difference between the upstream pressure gradient and the downstream pressure gradient is greater than a predetermined value, the occurrence of a gas leak is determined. Also, the occurrence of a gas leak is determined when each of the displacement of the upstream pressure gradient and the displacement of the downstream pressure gradient attains a predetermined relation.