An INTEREP expansion joint hard at work. Can’t see it? That’s because it’s doing its job. You can juuuuust barely see the gap in the telescoping flow-liners there. We used a braided seal and cavity packing to ensure that no dust would accumulate in the bellows convolutions, and that this expansion joint would be able to run for many years without any special attention… even in hot metals service, with slag, abrasive particulate, and sulfur gas!