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The Solution for Corrosion under insulation (CUI). 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: Save energy Control process temperatures Protect workers from high temperatures
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The Solution for Corrosion under insulation (CUI)
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: • Save energy • Control process temperatures • Protect workers from high temperatures • NACE Standard SP0198-2010 is a good source of information, but electrolytes will eventually find their way into even the best system
Anti-Corrosion Gel • Performance • Operating Temperatures – over 350° F/177 ° C • Moisture Resistance – Hydrophobic • Anti-Corrosion Properties – Mineralization, Inhibitors & Buffering Technology • Application • Surface Prep – no sandblasting, free of oils/greases • Cure Time – None, visual inspection easy and non-destructive • Equipment – Brush, PVC glove or spray • Environmentally benign • Cost • Total application cost is typically lower than other systems • Line shutdown not required
Technology • Barrier system – The specially formulated products have great adhesion characteristics (requiring minimal surface prep) and are hydrophobic to help keep moisture away from the substrate. Never cures thus microscopic air pockets don’t form. • Mineralization - Growing an engineered surface, or surface conversion – creating a surface which resists corrosion even if moisture gets to it. Undercutting cannot occur. • Buffering system – If moisture migrates through the gel through vapor drive, it is buffered to a high pH which is alkaline enough not to corrode metal. Gel also contains a number of corrosion inhibitors.
How the reactive gel corrosion treatment works: When the ferrous (steel) surface (1) is covered with a layer of reactive gel (2), the metal surface reacts with components in the gel to form a mineral layer (3). This thin glasslike layer (3) acts as a barrier between chlorides and the metal surface, thus providing corrosion resistance. The mineral layer (3) has a thickness of 50-200 angstroms, only 0.01% as thick as a piece of paper.
Although the thin mineral layer can be damaged by mechanical abuse, there is extra protection built into the system, i.e.: • If the mineral surface is scratched or damaged, and there is residual gel in contact with the area, the mineral layer will be regenerated by the gel ingredients. • The gel contains a buffering agent, which raises the pH of water at the surface of the steel to 10 or above, a level unfavorable for corrosion of ferrous substrates. (Another formulation for aluminum adjusts the pH to 6-8).
Surface Formation 10 um 10 um Untreated steel surface Mineralized steel surface
History of theTechnology • Automotive • Technology has been used in automotive applications for > 30 years. Originates before Second World War. • Crevice Corrosion on Brake Cables • Industrial Applications • First industrial application was with the US Navy. Solved their #1 and #2 corrosion maintenance problem. • Watertight Door Latching Mechanisms • Deck Edge Elevator Wire Ropes • Other specific areas
2 Year Salt Water Immersion Test Samples in Aerated 5% salt solution
2 Year Salt Water Immersion Test Samples in Aerated 5% salt solution
2 Year Salt Water Immersion Test Non-Bead Blasted Pipe Bead Blasted Pipe
Control Sample Typical Stress Cracking with in 100 hours of exposure Per ASTM C 692 Gel Treated Sample No Cracking After 100 Hours Exposure Per ASTM C-692 EDC 2400 Treated Sample No Cracking after 100 Hours Exposure Per ASTM C 692 Stress Crack Corrosion on SS
Ammonia Lines Flange Remediation Ammonia Test Site
AMMONIA SYSTEM INSTALLATION EXAMPLE ON OPERATING SYSTEM USING:
PICTORAL INSTALLATION REMOVING METAL JACKET
PRIMER ON INSULATION CORROSION ON PIPE
Pipe temperature thickens the RG-2400 LT quickly. After 3 passes over an area it gets difficult to spread and achieve adhesion. The slight frost on the pipe left some voids, however fresh “warm” material could be put over these areas and achieve ahesion. INSTALLING RG-2400 LT
CONCLUSIONS • COATING A 24° PIPE IN OPERATION IS POSSIBLE IN SMALL SECTIONS. • RG-2400 MUST BE WARM TO IMPROVE COVERAGE AND EASE OF APPLICATION • INSULATION MUST BE INSTALLED IMMEDIATELY UPON ACHIEVING COVERAGE TO PREVENT CONDENSATION FROM FORMING ON THE RG-2400 • INSULRAP OR FABWRAP VAPOR BARRIER SHOULD BE USED TO KEEP OUT MOISTURE • TESTING WILL CONTINUE ON -15° F LINES IN OPERATION AND -50° F LINES IN OPERATION. RESULTS WILL BE ADDED TO THIS PPT PRESENTATION. • GLYCOL WILL BE TESTED TO REMOVE FROST ON THE COLDER LINES.
Product Application - Tank The tank was completely sprayed in approximately one hour
Conoco/Phillips Well Casing WELLS WERE FIRST FLUSHED WITH 55 BARRELS OF 120° F CLEAN WATER TO REMOVE SLUDGE, WATER WAS PUMPED OUT AT END OF FLUSH CYCLE.
Companies With Product Installations/specifications • Anheuser Busch • General Mills • Jolly Green Giant • British Petroleum • Best Brands Foods • Philadelphia Gas • Fred Meyer Foods • Unocal • Dot Foods • Exxon Mobil • CODELCO • Tuborg • Efes Pilsen • GlaxoSmithKline • Shell • OxyChem • Ernst & Gallo • Equistar • Union Carbide • Cytec • Phillips • MODOT • Nicor • Monarch Foods • US Navy • Kraft Foods • ConocoPhillips • Coors Brewing • Canada Hydro • Indiana University
Benefits of the Technology: • Practical application – simple non-curing gel • Multiple delivery systems (spray, glove, brush) • Insensitive to surface preparation and application conditions • Demonstrated superior anti-corrosion performance • Environmentally benign • Easy to inspect