Expansion joints

Most metals expand as temperature rises and contract when it decreases. In pipelines this causes variation in the length of individual sections of the pipeline. As pipelines are normally anchored from at least two connection points, any variation in length causes thermal strain in the material and enhanced forces at the connection points. Pipe expansion is as far as possible compensated with the natural flexibility of the pipeline, but should this be insufficient, expansion joints are needed to compensate the movements.

In addition, expansion joints absorb mechanical vibrations of pumps, compressors, turbines and engines, which could otherwise cause damage to the adjoining pipelines, their supports or any other installed instruments.

Central component in expansion joints is the bellow, which thanks to its shape and thin wall acts like a spring. In order for the bellow to be suitable for use as an expansion element, however, it must meet the following criteria:

• The bellow must withstand the pipeline’s operating and testing conditions
• The bellow has to ensure corrosion resistance against both inner and outer conditions of the pipeline
• The bellow needs to be flexible enough to compensate for the thermal expansion and mechanical vibrations with the durability requested from it
• The bellow must include sufficient squirm stability

Our range of expansion joints has the right product to absorb either axial, lateral or angular movements. In addition to standard measures and materials, we also supply expansion joints customized especially to the requirements of your application.