Stainless steel bellows are designed to compensate for axial displacements. Slight lateral movements of bellows are acceptable but reduce the cyclic life expectancy if the allowable axial movement is used at the same time. The lateral movement on this type of expansion joint produces the highest forces and the most detrimental movement for this type of expansion joint. For this reason, axial expansion joints should be installed co-axially with the piping. The Stainless steel bellows should be made to avoid lateral movements by providing directional main anchors at the ends (two-direction supports acting at right angles to the axis of the pipe) to direct the piping growth into this joint only in the axial direction.
Requirement