Metal Bellows

METAL BELLOWS Metal expansion joints (MEJ) also called compensators or metal / metallic bellow. An expansion joint/bellow element employed in a piping system is an assembly of generally more than one convolute in series with the shape of the convolution designed to withstand the internal pressures, Thermal expansion, mechanical vibrations of pumps, draft fans, compressors, turbines, motors, vessels and other plant components, but flexible enough to accept axial, lateral, and angular deflections. They consist of one or more metal bellows. Metal expansion joints have to be designed according to rules laid out by EJMA (expansion joint manufacturing association).For Fabric & Rubber expansion joints there are guidelines and a state-of-the-art description by FSA (fluid sealing association). Expansion joints are differentiated according to the three basic types of movement: axial, angular and lateral expansion joints. The central component of each expansion joint is the metal bellows .Due to its shape and thin wall, acts like a spring. The bellows however has to meet the following basic criteria to qualify for its use as an expansion element. It must : • Withstand the operating and test conditions (pressure, temperature). • Ensure corrosion resistance. • Provide sufficient flexibility for the purpose. • Include sufficient squirm stability.