Two significant forces, which are unique in expansion joint are spring force and pressure thrust force. In addition to normal pipe systems force, the anchors in system should be designed considering expansion joint significant forces. An expansion joint must be installed so as its both ends are getting anchored.

Spring force is a force required to deflect an expansion joint the specific amount for which it is designed. In order for an expansion joint to operate properly, this spring force must be restrained by anchor/fixed point. The magnitude of spring force is determined by the expansion joint spring rate and the amount of the movement to which the expansion joint is based.

Pressure thrust force is a condition created by installation of flexible unit, such as an expansion joint into the rigid piping system, which is under pressure. Pressure thrust force is function of the system pressure and mean diameter of the Bellow. In case of internal positive pressure the convolutions are pushed out causing the bellows to open / extend or increase in the length. The force required to maintain the bellow at its proper length is equal to this pressure thrust and can be substantially higher than other system forces, combined.

The main anchor should be designed to withstand the force and moments imposed upon it by pipe section to which it is attached in the pipe section containing un-restrained expansion joint, these will be due to full bellow pressure thrust, media flow, the force and/or moments required to deflect expansion joint their full rated movements should be considered.

In certain application it may be necessary to consider the weight of the pipe section and its contents as well as other force and/or moments due to wind loading etc.

The following are suggested main anchor location in the systems, containing expansion Bellows :

Correct alignment of the pipe adjoining an expansion joint is of vital importance for its proper function. Although the expansion joints are designed and manufactured for a long and satisfactory life, maximum service will be obtained only when pipeline has recommended number of guides and is anchored and supported in accordance with good piping practice. Proper supporting of the pipeline is required not only to support pipe itself, but also to provide support at each end of the expansion joint. Pipe guides are necessary to ensure proper alignment of movements to the expansion joints and to prevent bucking of the lines.

While application involving axial movements only, it is generally recommended to locate expansion joint near to the anchor point.

For systems subjected to the lateral movements or angular movements directional anchor or planer guides are recommended.

The above piping guides and supports are suggestive and are minimum requirement. However additional piping supports and guides are often required between the guides in accordance with Standard Piping Practice.

'flexican' Metal Bellows Expansion Joints have been designed to absorb a specified amount of movement by flexing of the thin gauge bellows. If proper care is not exercised in the installation of the expansion joint, cycle life and pressure capacity could be reduced leading to premature failure.

It is important that the expansion joint is installed at the length in pipeline location specified. They should never be extended or compressed in order to make-up for deficiencies in length nor should they be offset to accommodate misaligned pipe. The bellows are thin flexing elements. The installer must recognize this and take every possible measure to protect it during the installation. Please avoid denting, weld spatter, and strikes or possibility of allowing foreign material to interfere with proper flexing of the bellows. With reasonable care during the storage, handing and installation the user will be assured of the reliability designed and built into the expansion joints.