Acoustic emission testing of underground pipelines of crude oil of fuel storage depots

Considerable quantity of underground in-plant pipelines of crude oil of fuel storage depots and refineries is operated for more than thirty years. Corrosion damages and material degradation are the main causes for structural failures of such underground pipelines. Such failures not detected on time and not monitored in time are potentially the reasons of major breakdowns of the infrastructure of technological underground pipeline installations in-service and finally are the risks of pollution of the environment. The preventive maintenance activities are usually carried out on time driven basis, but evolving defects have to be identified in time to enable appropriate repairs. The primary disadvantages are limited access to pipelines and limited possibilities of testing, due to the necessity for off-line pressure tests of a big part of underground pipeline installation, possible visual inspection and follow-up non-destructive tests (NDT). Based on these facts, we conducted investigations for application of AE testing method of underground pipelines during pressure tests using liquid product transported through pipe. We present the AE investigation on pipeline materials and on real underground pipelines.