Study on a Repair Clamp Device for Leakage Prevention in Defective Pipes

Clamp repair is a primary method for defective pipe rehabilitation, but the application of repair clamps can conversely affect the safety of the defective pipe. This study presents an optimized repair clamp structure for a defective pipe with diameter of 219 mm through finite element analysis and experimental validation, with a consideration of the sealing performance of clamp. The sealing capability is first verified by contact pressure analysis. When the medium pressure increased from 5 MPa to 20 MPa, the sealing contact pressure correspondingly rose from 11.6 MPa to 27.2 MPa, consistently exceeding the medium pressure. A sensitivity analysis of the maximum safe pressure of defective pipe is then conducted, evaluating critical parameters including defect dimensions, clamp installation distance, and applied pressure range. To ensure safe pipe operation, the recommended optimal installation distance is approximately 40 mm. A hydrostatic pressure test is performed for final validation. Results confirmed the clamp’s robust sealing performance, enabling defective pipe to operate normally at 7.5 MPa medium pressure.