Expansion Joints #4954854

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.

Hinged Expansion Jointed are usually used in a set of two or three, to absorb lateral deflection in one or more direction in a single plane piping system. The Joint in such system is restricted to pure angular rotation by its hinges. Each pair of hinged Expansion Joints, separated by a segment of piping, will act in unison to absorb lateral deflection in much the same manner as a swing or universal Expansion Joint in a single plane application. For a given angular rotation of the individual Expansion Joints, the amount of lateral deflection that a pair of hinged Expansion Joints can absorb is directly proportional to the distance between their hinge pins. In o

Gimbal Expansion Joints usually have a singular Bellows component. Gimbal expansion joints are designed to permit the angular rotation in any direction by using two pairs of hinges that are connected to a common floating Gimbal ring. The Gimbal ring, hinges, and pins are designed to restrain the thrust of the Expansion Joints as a result of pressure and external forces. The advantage of Gimbal Expansion Joints is that they are not limited to only single plane systems, making them very useful for various applications.

The In-Line Pressure Balanced Expansion Joint is used in applications where pressure loading upon piping or equipment is considered excessive or objectionable. The major advantage of the In-Line Pressure Balanced design is its ability to absorb externally imposed axial movement without placing pressure loading on the system. The force resulting from the Bellows spring rate is not eliminated. In fact, it is usually increased over that of a single Expansion Joints. Since both the flow Bellows and the balancing Bellows must be compressed or elongated, and the combined axial force acts upon the piping or equipment. Since the forces that move the Bellows are of a low order of magnitude. These are usually not objectionable, except in cases involving extremely light equipment with close clearance moving parts that might be affected by small forces.

Refractory Lined Expansion Joints are also meant to endure extremely high temperatures and pressure applications. The refractory lining within the metal expansion joint reduces the pipe wall temperature by 300F to 450F, depending on the thickness of the refractory lining. The lining also helps to withstand the abrasive material from the catalyst in FCCU applications.