During the erection of piping systems, the accuracy of the location of equipment, pipe supports, structure and the piping itself is never perfect. Since the pipe expansion joint is usually far more easily deflected than any of these other components, it is tempting for piping installers to use it to correct for misalignment. The installation instructions of PT&P's pipe expansion joints, as well as other manufacturers, require that the piping be aligned to the pipe expansion joint during installation. The pipe expansion joints will arrive from the factory with rigid restraints which maintain their length and ends in the position and dimensions of the specification in this catalog.
If some misalignment must be accepted by the pipe expansion joint, this can be accommodated by the addition of devices such as limit rods which can be used during the installation to adjust the pipe expansion joints to fit. Any proposed misalignment should be clearly stated to PT&P so that the amount of deflection possible can be considered in the total deflection capability of the proper selection. As an example, one would not want to have a needed cyclic axial compression capability of 0.5 inch (12.7 mm) cut in half by a compression due to pipe misalignment of .025 inch (6.4 mm).