Rectangular expansion joints are generally made for specific applications.
EGP designs and manufactures a wide range of rectangular joints to offset axial and lateral movements, with different cross sections and for different operating conditions.
Rectangular joints are available in four different types of corners and two basic profiles (see sketches).
The basic part of an expansion joint is the bellows, which must be strong enough to withstand the circumferential pressure but flexible enough to absorb deviations to the designed level as many times as necessary.
The trade-off between strength and flexibility is a problem which engineers solve according to operating conditions when they design the bellows (nº of convolutions, thickness, height, nº of layers, etc.) and in their choice of material (AISI 304, 316, 321, 400, etc.)
Pressure depends on working temperature, diameter and convolutions.
Temperature affects the strength of materials, and must be taken into account when determining the pressure resistance of the convolutions and the thickness of the various components. Movement is also affected by temperature. Depending on the material involved, temperatures of between -196 and +800º C are possible.
The standard range of EGP metal expansion joints runs from nominal diameter (ND) 50 to ND 2000, though larger sizes can be made in special cases, in circular or rectangular shapes.