HEB - Hinged Expansion Bellows
Individual Aflex Hinged Expansion Joints allow for angular rotation about its hinges, in a single plane. HEB are usually used in sets of two or three to absorb large amounts of lateral deflection, due to the thermal expansion of the pipeline. The hinges are designed to restrain the full pressure thrust from the bellows and can also be designed to support the weight of piping and equipment, as well as other external forces. This means Aflex HEB systems generate very low forces on the piping and do not require main anchors.
An example of the use of a pair of Aflex HEB can be seen in the diagram on the right, where the thermal expansion of a long pipe section is being accommodated by lateral deflection in a 90° offset pipe leg.