At present Transneft operates 1500 underwater crossings at water bodies having the total length over 3200 km. During their operation, deviations from the planned altitude position may form. Various defects can be detected on the pipe sections, such as metal loss (corrosion), indent, buckle, delamination, groove, crack etc.
Transneft UW Service, JSC, carries out all maintenance, inspection and repair works on underwater crossings. It comprises 35 engineering survey teams, 69 divers at 18 diving stations, and 5 construction and erection work sections.
An integrated approach to the issue of aging of pipelines, conducting periodic diagnostics, including using the unique GK-25 sealing chamber complex, timely repair of pipelines and monitoring, both on land and at underwater crossings, allows ensuring their reliable and safe operation, despite long lifetime.