OFF-Shore Crude Oil Pipeline Flange Leak - VKVC FLANGE REPAIR SUB-SEA
Overview A 48 ”NB Pipeline from SBM to the tank farm developed a leak on one of the flange joints on a spool piece near the SBM. The water depth was approximately 35m. The leakage Point in the Gasket face could not be located due to poor visibility. VKVC was called in to provide a leak sealing solution on emergency basis.
Solution & Implementation Flange leak sealing involves Leak sealing in 2 Stages. Stage-1 Installation of Clamp. Stage-2 Injection of sealant to seal the annulus between studs and nuts of Flange Joint. Stage-1 Installation of Clamp was completed without any complication. During Stage-2 injection of sealant the viscosity of sealant prevented it from being injected from a distance of approximately 60 meter. 35 meter water depth and 25 meter hose leeway. The first attempt was abandoned as sealant did not reach the Clamp. A low viscosity Epoxy sealant was tested at VKVC Works for Pumping from 100 meter distance into an artificially pressurized chamber containing a dummy Clamp. The trials were successful. The low viscosity Epoxy sealant was then injected into the Clamp at site.
Result The Flange joint is operating successfully with VKVC Clamp till date approximately 3 years in service.