Abstract
AbstractPolymeric pipes are favorable over other materials in many applications due to their ease of handling and resistance to corrosion. PVC is the most reliable piping material to resist ruptures in water drainage systems. When used in home and industrial water supply and drainage, PVC pipes are typically joined to couplings, angles, and junctions by solvent welding. Solvent welding of PVC pipe joints can take hours to fully cure and requires adequate ventilation, which can postpone the use of high-priority pipe systems in need of repair. Mechanical joints make rapid assembly possible, but are more prone to leaks than welded joints. An alternative PVC pipe-joining method uses friction stir welding (FSW) to join PVC pipes and couplings. This study brings a novel application to FSW and determines its feasibility for jobsite PVC pipe joining through examination of processing forces, chemical changes in the welded joints, joint performance under tensile load, joint performance under hydraulic pressure, and overall processing times. Analysis of welding forces indicated relatively low machine requirements that justify the capability of small, portable FSW machines that are not possible for most current FSW applications. Thermal analysis showed that FSW poses little health risk when joining PVC pipes due to a lack of thermal degradation that would release toxic gases. Pipe joints subject to hydraulic pressure surpass current burst pressure standard requirements for all tested welding speeds. Thus, this study demonstrates welded PVC pipe coupling joints with exemplary pressure capability formed on the order of several minutes, reducing overall processing times from up to several hours that may be necessary to fully cure a solvent weld.