Corrosion under insulation cui is a problem in the industrial sector, including refining, petrochemical, power, industrial, onshore and offshore industries and it is a real threat to the on stream reliability of many of todays plants. Corrosion in the external surface of piping and equipment. Delahunt in corrosion control under thermal insulation and fireproofing 1 shows the seriousness of the problem by presenting case histories. Jan 31, 2019 the difficulties and expense of looking for and preventing the very common but elusive problem of corrosion under insulation cui is widely known and well documented cui is hard to find because its hidden under the insulation and there are substantial costs and logistical issues involved in removing the coverings, inspecting the piping and then reinstating the coverings. Corrosion under insulation cui is a major problem for petroleum and chemical process industries. In cs, cui occurs in piping or equipment with a skin temperature in the range of 25350f 4175c, where the metal is exposed to moisture over a period of time under any kind of. It is estimated that up to 10 percent of annual maintenance costs in these industries are caused by cui. However, experimental studies investigating cp of steel through moist insulation are scarce. Corrosioncorrosion under insulation cui carbon steelstainless steelcoating. Pdf like other natural events, earthquakes or bad weather, corrosion is a natural event that results in expensive damage that effects almost. Appendix d case studies of 1 a national oil company, 2. Corrosion under insulation cui occurs when watermoisture is trapped under insulationfireproofing. The pulsed eddy current technique has been deployed previously for corrosion under insulation inspection.
Corrosion under insulation inspection and prevention. On the mitigation of corrosion under insulation cui of mild. Such techniques use a large probe to give an adequate size of field and are relatively slow in application. These cover deep pitting, as well as general corrosion, that have occurred on galvanized steel. Corrosion under insulation cui is one of the industrial sectors greatest challenges with respect to materials.
Corrosion under insulation cui refers to the external corrosion of piping and vessels that occurs underneath externally cladjacketed insulation as a result of the penetration of water. Although the cause of the fire was inconclusive, the onsite investigation. Pdf corrosion under insulation cui is a very important issue in industry and its importance is being more and more acknowledged. The 7 inspection methods you must know about published on april 14, 2016 april 14, 2016 745 likes 74 comments. Corrosion under insulation cui is widely acknowledged to be a critical issue facing plant operators. Solutions that can detect and locate damages under insulation without stripping off insulation and withoutreduced need of scaffolding.
This practice dnvglrpg109 riskbased management of corrosion under insulation was developed as part of a collaborative project with partners from across the oil and gas industry. Corrosion under insulation cui is the corrosion of piping and vessels that occurs beneath insulation as a result of water penetration. Rockwool technical insulation corrosion under insulation. Failure of inservice equipment can be catastrophic and extremely costly. The recommended practices in this standard are intended to provide the user with. New developments in automated inspection for corrosion under. Its a major issue that needs to be addressed from the design phase until decommissioning of equipment. Guidelines for reducing corrosion under insulation. Corrosion under insulation training organized by fleming. Corrosion under insulation cui is defined as a severe localized form of corrosion due to entrapped water under the insulation layer of piping and vessels. Api rp 583 corrosion under insulation and fireproofing. It is estimated that 4060% of pipe maintenance costs are a result of cui, and 10% of total annual maintenance costs in these industries is dedicated to repairing damage caused by cui ii, iii. The type and rate of corrosion under insulation will vary depending on certain factors, including insulation type, temperature variance, coating protection, pipe metallurgy and environmental influences eg a severe rain storm or deluge system testing.
Corrosion under insulation cui is a damage mechanism that affects all industrial facilities. The water can come from rain water, leakage, deluge system water, wash water, or sweating from temperature cycling or low temperature operation such as refrigeration units. Defects in the coating like dents, damages, degradation or loss of coating that can lead to corrosion of underlying steel. Corrosion under insulation cui and the insulation system. Cui is a subject that is well researched and understood. External corrosion of carbon steel piping, pressure vessels and structural components resulting from water trapped under insulation in conjunction with other variables that accelerate and drive the corrosion external chloride stress corrosion cracking of austenitic and duplex stainless steel under. Corrosion beneath the insulation blankets was severe and affected the exhaust piping at the same points as the unit that experienced the fire. It provides a novel methodology to guide asset managers on the most effective and efficient way to assess, mitigate and systematically manage the risk of cui. Corrosion of steel under insulation is considered to be one of the major problems which has caused damage to the petrochemical industry. Vapor phase corrosion inhibitors preventing corrosion under. Stefan winnik, author of efc55 corrosion under insulation cui guidelines, has retired and entered into an agreement with kaefer to ensure the continuation of his successful cui training course and knowledgeshare.
The enemy note that we used club soda, which contains chemicals, just like the water that gets under jacketing. Nov 19, 2008 corrosion under insulation cui is a major problem for petroleum and chemical process industries. The potential influence of thermal and acoustic insulation materials is normally assessed through a series of. Because the corrosion is hidden under the insulation, cui tends to. Corrosion under insulation cui is a major safety threat to chemical processes with pipes and pressure vessels for moving and storing fluids where anions and cations are transported via water to pipe surfaces to corrode away pipe surfaces. This recommended practice rp covers the design, maintenance, inspection, and mitigation practices to address external corrosion under insulationcui and corrosionunder fireproofingcuf. Apr 14, 2011 corrosion under insulation cui is the corrosion of piping and vessels that occurs beneath insulation as a result of water penetration. This recommended practice rp covers the design, maintenance, inspection, and mitigation practices to address external corrosion under insulation cui and corrosionunder fireproofingcuf. New developments in automated inspection for corrosion under insulation john rudlin, twi limited, cambridge, uk abstract detection of corrosion under insulation cui has been a major problem for the oil, gas and chemical industries for many years. Pdf corrosion under insulation and fireproofing henrique. The guidelines cover a riskbased inspection methodology for cui, inspection techniques including nondestructive evaluation methods and recommended best practice for mitigating cui, including design of plant and equipment, coatings and the use of thermal spray techniques, types of insulation, claddingjacketing materials and protection guards. Corrosion under insulation cui inspection technique and prevention. Corrosion under insulation cui is a major issue for oil, gas and chemical process industries.
Corrosion under insulation cui cui has been recognized as a problem in many industries insulation is a necessary component of the system and is designed to. Corrosion under insulation the hidden problem cui exposures can occur on both carbon steel cs or austenitic and duplex stainless steel ss substrates. Corrosion corrosion under insulation cui carbon steelstainless steelcoating. Current industry practices for detection and mitigation are inefficient and expensive. Corrosion under insulation cui is corrosion that results from moisture buildup on equipment covered by insulation. A holistic approach to insulation system design to reduce risk of cui on industrial piping. Corrosion under insulation cui is one of the most well known phenomena in the process industries, and yet it still makes up an inordinately large percentage of global maintenance expenditures. Corrosion under insulation cui is a wellunderstood problem, and mitigation methods are well established. All information about the articles is based on the original dates of publication of these materials in jpcl. This analysis gives a basis for further inspection and testing, allowing technicians to understand facility processes and identify any preliminary risk factors or warning. Herein, cp was explored to protect insulated steel specimens using sacrificial zinc anodes.
A strategy based on cathodic protection cp could be a practically feasible means to protect steel piping from corrosion under insulation. By selecting the best available solution, the effects of cui could be mitigated. The document does not cover atmospheric corrosion or corrosion at uninsulated pipe supports but does discuss corrosion at. The key issue in this case was the incorrect specification of ioz silicate for use in this temperature range under insulation. In july 2018, the bureau of safety and environmental enforcement bsee investigated a platform diesel generator fire that occurred inside of a generator enclosure. The 4 best nondestructive inspection methods for corrosion. Api rp 583, corrosion under insulation and fireproofing, covers the design, maintenance, inspection and mitigation practices for pressure equipment, piping, and storage tanks due to external corrosion under insulation cui and corrosion under fireproofing cuf. Apr 05, 2018 the international standard organization iso has, under tc67, formed a working group wg11, which is going to develop isonp 19277 methods for control of corrosion under thermal insulation and fireproofing materials.
However, it is pervasive and continues to cost the process industry many millions of dollars annually. Corrosion under insulation cui management mistras group. Vapor phase corrosion inhibitors preventing corrosion under insulation corrosion under insulation cui is a serious concern both in terms of monetary loss and danger to personnel safety. Dnvglrpg109 riskbased management of corrosion under.
Corrosion under insulation cui guidelines 2nd edition. Mistras provides comprehensive corrosion under insulation cui prevention and mitigation programs, including integrated inspection, maintenance, and monitoring solutions without an effective corrosion under insulation cui protection program, the resulting damage can be difficult to detect, harder to manage, and comes with a devastating cost. Corrosion under insulation and fireproofing api recommended. Save energy control process temperatures protect workers from high temperatures nace standard rp0198981 is a good source of. Corrosion under insulation cui is a very important issue in industry and its importance is being more and more acknowledged. The european federation of corrosion efc working parties wp and wp15 have worked to provide guidelines on managing cui together with a number of major european refining, petrochemical and offshore companies including bp, chevrontexaco, conocophillips, eni, exxonmobil, ifp, mol, scanraff, statoil, shell, total and borealis. The worst part of the corrosion was found in temperatures between 71 and 82c 160180f. The choice of insulation system is a critical factor in. Corrosion under insulation cui is a form of corrosion that occurs when moisture ingress through insulation and comes into contact with underlying metallic equipment. Although the extent and resultant cost of corrosion under insulation cui are not known exactly, j.
European federation of corrosion publications number 55corrosion underinsulation cui guidelines s. The incident the failure of a 8 inch carbon steel, high pressure hydrocarbon line due to corrosion under insulation on march, 2008, at a dows lhc plant, an 8 inch, schedule 20, carbon steel hydrocarbon line failed. Part of this is to develop a standard that can be used to test and evaluate insulation systems and the effect of cui. On the mitigation of corrosion under insulation cui of. More lessons relearned from corrosion under insulation. Corrosion under insulation cui is a major safety threat to chemical processes with pipes and pressure vessels for moving and storing fluids. New developments in automated inspection for corrosion. Save energy control process temperatures protect workers from high temperatures nace standard rp0198981 is a good source of information, but electrolytes will eventually find their way. Corrosion under insulation cui on industrial piping is a major issue for the oil and gas industry. It is a top culprit for piping leaks and near misses and results in significant maintenance costs. Often ingress of water can happen when there is damaged insulation, break in vapour barrier, break in mastic sealing or areas of entrapment, such as the end of flanges or equipment with insulation support rings can serve as areas for water entrapment.
The technique developed here differs from those used previously in that the intention at the outset was to inspect a large area i. Cui can result in sudden and hazardous leaks safety concern, and plant shutdowns with high losses of production. Corrosion under insulation on inorganic zinc pipe section. By its very nature cui tends to remain undetected until the insulation and claddingjacketing is removed to allow inspection or when leaks occur. Stress corrosion cracking mechanism, types of alloys susceptible to corrosion, factors influencing corrosion, and corrosion prevention methods, are also discussed. Corrosion uner insulation on inustrial piping 2 a holistic approach to insulation system design to reduce risk of cui on industrial piping. Cui is commonly classified as galvanic, chloridic, acidic, andor alkaline in nature. Corrosion under insulation cui guidelines efc pdf free. The document does not cover atmospheric corrosion or corrosion at uninsulated pipe supports but does discuss corrosion at insulated pipe supports. The recommended practices in this standard are intended to provide the user with information that.
167 1058 538 383 590 173 230 1474 988 788 1203 482 1012 742 309 723 797 1455 179 933 552 570 121 696 440 878 1057 1451 1478 580 407