In the event of flow rates greater than 30 m/s, we recommend using flow liners in order to avoid turbulence in the area of the expansion joint. Due to the rebound elasticity of the rubber, for elastomer expansion joints, the flow liner can be dispensed with in the event that the medium exhibits a low solid fraction and high flow speeds.

Depending on where the joint is installed along the duct, e. g. after a bend or if the installation is horizontal, vertical or diagonal, the solids in the medium may expose the expansion joint to wear. The volume and particle size of these solids influence the choice of material. In the event of high concentrations of dust, soot, flue ash or similar solids, we recommend that you use flow liners.