The 18” class 300 butane line operating at 12 bar (175 psi) was a significant length – approximately 11 kilometers. The pipeline design made it impossible to fully drain and refill the pipeline with butane, thus utilizing conventional technologies would mean replacing the line. A variety of engineering solutions were considered which could minimize pipeline downtime whilst replacing the flow meter. Located in a residential area, the asset owner understandably wanted to avoid the risks, complex operations and major costs associated with this course of action. There were no suitable means for isolation near the maintenance point limiting intervention options for the operator. In addition, asbestos was discovered in the gasket, necessitating supplementary specialized procedures for safe handling, decontamination, replacement and disposal.