INSTALLATION ASSEMBLIES FOR PIPELINE LINERS, PIPELINE LINERS AND METHODS FOR INSTALLING THE SAME

摘要

An installation assembly ( 20 ) for installing a liner (L) in a pipeline (P) comprises a double bladder assembly ( 22 ) including an inner bladder ( 26 ) having an installation end ( 26 b) and a retrieval end ( 26 c). An outer bladder ( 28 ) surrounds the inner bladder. The ends of the inner and outer bladders are coupled together adjacent the installation end via an inversion element ( 30 ). The inner bladder is coupled to an air source at its retrieval end and the outer bladder adjacent the retrieval end is free. Following installation and curing of the liner, the bladder assembly is retrieved by pulling on the retrieval end of the inner bladder, and upon retrieval, the outer bladder is inverted.