Diagnostics of welded joint damaging of polyurethane foam insulated pipelines

Polyurethane (PU) foam insulation is widely used on various process purpose pipelines. However, on PU foam insulated pipelines, due to problems with self-compensation of thermal expansion, more intensive damage development of girth welded joints is observed. The article presents experience in solving the problem of timely detection of welded joints with developing damage ahead of the estimated time through the use of complex diagnostics on heat lines and gas and oil PU foam insulated pipelines using non-contact magnetometric express inspection in combination with additional non-destructive testing in areas of test drilling and insulation opening.