Hyspan Perma-Pax Packed Expansion Joints are a premium quality product with standard features that are either not available or only offered as options for comparable products.
The body is made from one piece, eliminating a circumferential weld in the outer diameter. Internal and external guides are made from an aluminum bronze bearing material that is welded in place and line bored for alignment and a precision fit. The sealing system consists of carbon fiber yarn impregnated with graphite and injected Grafoil® Flexible Graphite that has been optimized to minimize friction. These sealing materials remain flexible throughout the service life of the expansion joint, and have the added benefit of providing lubrication to the traveling pipe.