Single Tied Expansion Joint

Single Tied Expansion Joint is identical to the single unrestrained expansion joint, the only difference being; it is supported with tie rods. When tie rods are added to the expansion joint, it constrains the Bellows, eliminating overextending. Stops are set to allow axial movement for their intended design and motion.

Where appreciable amounts of lateral deflection are imposed upon the Expansion Joint, some shortening of the Expansion Joint results from the displacement of the tie rods.  Care should be taken to ensure the sufficient piping flexibility exists to absorb this deflection, and that adequate clearances are provided in the guide to permit deflection of the piping.  The amount of the deflection can be minimized by cold springing the Expansion Joint in the lateral direction.  The principal restriction upon the use of a single Expansion Joints for lateral deflection or combined axial movement, and lateral deflection is the limited amount of lateral deflection that such an Expansion joint can absorb.  The allowable lateral deflection is directly proportional to the ratio of convoluted length to diameter that, in turn, is restricted by  considerations of stability and manufacturing limitations.  While eminently suitable for the principal movement is axial, the relatively available lateral movement severely limits the type of application.  Where operation pressures and temperatures are high, or where availability of suitable structures precludes the use of main anchors and multiple guides, the application may not be feasible and another type of Expansion joint may result in far more economical installation.