Corrosion under insulation (CUI) is a major problem for petroleum and petrochemical process industries that affects the plant mechanical integrity and attacks assets. CUI can result in sudden and hazardous leaks (safety concern), and plant shutdowns with high losses of production (economical concern).
Traditional detecting methods of CUI to cut a window in thermal insulation used to inspect visually, to measure the thickness, and then return thermal insulation back, giving high chance for water and moisture ingress, accelerating CUI, moreover big amount of scaffolding erection along with thermal insulation removal required.
SHARQ (Eastern Petrochemical Company, one of SABIC companies) is pioneer to study CUI, evaluating many Non–Destructive techniques has proven Pulsed Eddy Current (PEC) as the most effective technique in terms of integrity and cost optimization.
Considering all available techniques, all aspects studied, such as range of applications, features, and limitations, it is concluded and verified to meet our inspection plan strategy needs.
PEC does not require thermal insulation removal; optimize scaffolding erection, has a wide range of applications related to thickness, and temperature. PEC approved by international codes and standards (API) to meet RBI Meridium software requirements.
The validation study results show cost savings of more than 50% compared to traditional thickness measurement methodology, moreover it reduces EHSS (Environment, Health, Safety, and Security) negative impact reduces the probability of safety incidents due to reducing labor, man-hours, and eliminating many associated activities with potential hazard and risk.
PEC has high productivity, easily operated, and provides comprehensive and professional inspection report

Pulsed Eddy Current (PEC) technology is a widely accepted inspection method now covered by several industry standards such as ISO⁽¹⁾ 20669, API⁽²⁾ RP 583, and the new ASME⁽³⁾ Section V (BPVC for Boiler and Pressure Vessel Code), article 21. PEC is a versatile inspection technology which provides an average remaining wall thickness through insulation and coatings. The technique can also be used to safely assess the minimum remaining ligament under corrosion scabs or blisters without surface preparation. PEC is resilient to liftoff variations and provides volumetric measurements of remaining material. It is capable of both detecting and assessing general corrosion on the outer surface of the pipes such as scabs and blisters, and detecting erosion or Flow Accelerated Corrosion (FAC) on the inner surface.