A building joint is installed in a structure so that static loads are not transferred from an element of the structure to another due to movement.
When piping crosses a building joint, an expansion joint must be installed to prevent building movement from damaging the piping system. The expansion joint must be able to handle movements in all directions (X, Y, and Z planes). The ideal joint for this application is a MetraLoop. If there is a space constraint the Seismic Gator can be used. Seismic Gators develop much higher anchor loads than Metraloops, see “How do I calculate in line bellows anchor loads”.
Although a building joint may resemble a seismic joint, it is not required to restrain the piping on each side of the building joint. We recommend using slide guides on each side of the Metraloop.
In many cases the building joint expansion joint will be used to handle the thermal movement of the adjacent piping as well as the design movement of the build joint. In this case the thermal movement and the building movements must be added together to properly size the expansion joint.