There are certain criteria for selection of expansion joint, for fluid piping application that focuses on the joints durability, quality and capabilities. To ensure the expansion joints installation operates and provides optimal and maintenance personal must take systematic approach and consider specific conditions. Some degree of flexibility is necessary for piping system. The inadequate flexibility can lead disastrous, life threatening system failure, thus making flexibility an important issue while selecting the joint.
Selection of Joint
The expansion joint provide maximum flexibility and can have all directional capacity that is based on the system requirement. These joints are designed to handle bidirectional lateral, torsional and axial movements of piping system. These movements can result in piping misalignment during the construction stage. The joints can absorb vibration that occurs with mechanical equipment rotation. The joints in fluid piping system provides these advantages in small possible space, thus keeping piping overall footprint and keeping the piping system at minimum. With the advent of piping system, which uses high-density installation these joints, seal better against the full-face flanges. For these reason expansion joint is key to piping system. When the joints are selected, the personal equipment and piping attachments should be reviewed.
Installation of Joint
Pump flanges with lug style connections can create sealing issues because the sealing area of the joint is reduced significantly. This sealing difficulty can be amplified when the joint is installed in an offset condition. When installing these joints against HDPE pipe, failure of the element and surge condition can occur against the edge of the HDPE pipe. Installing a joint to full fledge flange ensures the seal function in an effective manner at the time of pressure surges and normal operation.
Connecting these joints with valves can lead to premature failure. Thus, the recommendation installations needs to done against flat – face flanges whenever possible.
Sometimes a valve disc may encounter the inside diameter of mating joint body as it opens, and causing the premature failure after cutting into joint element. The sealing surface also is reduced when it meets expansion joints and can cause leakage during the time surge conditions.
