A magnetic flowmeter flowtube assembly includes a conduit having a first end with a first flange and a second end with a second flange. A fluoropolymer liner is disposed within and extending through the first flange, the conduit and the second flange. A first lining protector is mounted to the first flange and a second lining protector mounter to the second flange. A first spring-energized seal is disposed between the first lining protector and the fluoropolymer liner. A second spring-energized seal is disposed between the second lining protector and the fluoropolymer liner.