CCWI2017: F85 'A THEORY FOR REALISTIC MODELLING OF LEAKAGE AND INTRUSION FLOWS THROUGH LEAK OPENINGS IN PIPES' CollinsRichard Van Zyl JE ALambert 2017 The hydraulics of leakage and intrusion flows through leak openings in pipes is complicated by variations in the leak areas due to changes in pressure. This study presents a theoretical framework for the analysis of both leakage and intrusion flows through real leaks in pipes. A linear area- pressure relationship is assumed. The leakage exponent of a given leak opening is shown to generally not be constant with variations in pressure, and to approach infinity when the leakage number approaches a value of minus one. Significant modelling errors may result if an exponent used in the power equation used beyond its calibration pressure range, or at high exponent values.