Operating Principle


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The purpose of an Expansion Joint in general, regardless of design or materials of construction, is to provide a point of flexibility in a piping or duct system in order to absorb the growth of the piping due to thermal changes in the media and/or the environment, and to absorb the dynamic movements of machinery, buildings and structures that the piping is attached to or a part of.
The Rubber Expansion Joint, because of the non-metallic nature of its construction, offers the piping and ductwork designer advantages within the temperature and pressure ranges of these joints, which cannot be matched by  all metal expansion, joints.
Consisting of flanged ends and a flexible section, much the same as a flanged metal bellows, the rubber expansion joint can absorb within its free length more movements, particularly lateral, than any other joint of similar overall size and pressure rating.
The flexible section of a Rubber Expansion Joints is most often a single convolution, which, because of the inherent flexibility of the materials, can accept large lateral movements with low force, a phenomena which requires multiple convolutions in metal bellows. During axial and angular movements, the rubber convolution deflects much the same way that the metal convolution does. The limits of these motions are determined by the geometric shape and size of the convolution and the inherent pressure resisting capacity of the design.
The manner in which the pressure loads are resisted in a Rubber Expansion Joint is the major difference between Rubber and Metal Bellows. Circumferential (hoop) loads due to pressure are carried by the convolution itself in metallic bellows. In a Rubber Expansion Joint, the convolution is basically incapable of resisting pressure by itself, but is supported by the adjacent rubber tube with its internal fabric and/or fabric - metal reinforcing, or by the attachment flanges themselves.
All Easyflex Units have integrally molded flanges, sized and drilled to match standard flanges. All Rubber Expansion Joints require metallic split retaining rings behind the flanges to back up protect the rubber integral flange. Control rods must be used to protect expansion joints from excessive movement if piping system is not properly anchored and are normally recommended for most piping installations.



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General Information
Operating Principle
Rubber Expansion Bellow Types
Rubber Expansion Bellow Accessories
Installation Instructions
Quality & Testing Capabilities
Order Information


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