Corrosion Under Insulation

Corrosion Under Insulation (CUI) is perhaps one of the most significant integrity threats that the oil and gas industry faces today. Water ingress causes damage to pipework and other susceptible steel elements, but the corrosion process underneath existing insulation materials is one of the most difficult to prevent.

A common inspection technique used for CUI is to simply remove the insulation and perform a visual inspection initially.

The removal and reinstatement of insulation is labour intensive, expensive and in many instances completely unnecessary, as the substrate can often be found to be in good condition.

Up to 60% of pipe leaks are attributed to CUI.

Despite the problem being well understood and documented, the corrosion process under insulation is one of the most difficult to prevent.

It‘s time that changed.

Bilfinger Salamis offers a complete CUI management programme encompassing inspection, maintenance and repair (IRM).

Combining knowledge and capability across a range of disciplines makes the management of CUI a seamless process with one contract and one fully integrated team.

Advanced Detection Technology

Pulsed Eddy Current (PEC) is one of the most effective and efficient methods of determining the severity of CUI with minimal intervention, reducing the costly need for insulation removal and replacement in certain situations.

PEC inspection is an established and proven electromagnetic technique. It works by injecting an electrical current in the transmitting coil of the inspection probe, which in turn induces a magnetic field into the underlying structure.

PEC readings as recently as early 2016 needed to be carried out on a point-to-point basis, making it time consuming to capture all of the angles and positions required to scan a length of pipework.

Bilfinger is UKAS – ISO/IEC 17020:2012 accredited for the application of PEC, and has over 8 years’ experience across a range of applications worldwide.

We use handheld Eddyfi Lyft™ PEC systems for rapid real-time inspection data of wall thickness with full traceability. This innovative system runs continuously, reducing the time required and significantly increasing the number of data points available, providing greater certainty of results.

Rapid Close Visual Inspection Teams

Bilfinger Salamis combines these innovative technologies with multi-disciplined rapid close visual inspection (RCVI) teams that consist of multi-disciplined rope access personnel who can quickly deploy a range of CUI management processes.

These teams include specialists for access, survey inspection, and advanced NDT, as well as coatings, insulation and other specialist areas.

The RCVI teams can quickly access remote areas, conduct an initial survey to highlight potentially sensitive areas, perform relevant inspections, conduct any coating repairs, and reinstall insulation, getting an asset back in working order with minimal interruption to service.

We focus on minimising resources needed to carry out the work. Our inspection and fabric maintenance departments work together, using three-man multi-skilled teams that include an inspector, insulator and painter, all of whom are rope access qualified.

Bilfinger are in a unique position within the industry to be able to combine all of the above services into one multi-disciplined team, reducing labour costs and providing optimum results for asset owners.

One contact - one contract.

End-to-End Strategy

Access Methods

  • Rope access
  • Conventional scaffolding
  • System scaffolding (both steel and lightweight aluminium)
  • Tensioned under deck systems
  • Suspended work cradles
  • Lightweight portable access platforms

Surface Preparation

  • Blasting
  • Bristle blasting
  • Mechanical preparation

Coating systems

Insulation systems

  • Heat conservation
  • Winterisation
  • Personal protection
  • Cold conservation
  • Acoustic insulation



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