This model is made up of two bellows joined together by a central pipe and a system of tie rods able to withstand the thrust produced by the internal pressure.
This model is used to absorb lateral movements in all planes. In addition and with a special design and/or positioning of the tie rods system this type may be used to absorb some axial and angular movements*.
The tie rods are provided in sets of two or more, equally distributed around the circumference of the expansion joint. When the Expansion Joint is supplied with 2 tie rods at 180 degrees, the expansion joint is free to deflect angularly and laterally. With three or more tie rods only lateral deflections are possible.
The amount of lateral deflection depends on the amount of angulation each bellows can absorb and the length or the central pipe. The amount of lateral deflection capability can be increased or decreased by simply changing the length of the spool pipe and the thermal expansion of the central pipe is taken by the bellows elements.