Author Archive: beatcorrosion

MFL Tool for In-line Inspection (ILI)

beatcorrosion March 25, 2016 0 Comments

Principle of Magnetic Flux Leakage (MFL) A magnetic flux leakage (MFL) inspection is the type of in-line inspection technology in which a magnetic saturation is induced in the pipe wall between two poles of a permanent strong magnet. The pipe wall is magnetised by using this magnet. Anomalies affect the distribution of the magnetic flux in the wall, by which it is used to detect and characterize anomalies accordingly. Any metal-loss in the pipe wall will cause the induced magnetic flux leakage, which can be monitored using a detector and hence metal-loss defects can be identified and sized. MFL can…
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Corrosion Management, Corrosion Test

Corrosivity categories for coating systems selection by ISO 12944

beatcorrosion March 8, 2016 0 Comments

Atmospheric corrosivity categories for coating systems selection by ISO 12944 Corrosivity category Service environment (Exterior) Service environment (Interior) C1 very low Heated buildings with a clean atmosphere C2 low Atmosphere contaminated to a small extent, mainly rural regions. Buildings which are not heated, where condensation may occu C3 medium Industrial and urban atmosphere with an average sulphur oxide (IV) contamination level. Inshore areas of low salinity. Production space of high humidity and certain air contamination e.g. foodstuff plants, laundries, breweries, dairies. C4 high Industrial areas and inshore areas of medium salinity Chemical plants, swimming pools, ship repair yards. C5-I very…
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Coatings, Materials Selection

Attaching of cathodic protection cable by pin brazing and cadweld

beatcorrosion March 7, 2016 3 Comments

Attaching of cathodic protection cable by pin brazing and aluminothermic weld (Cadweld) Brazing is the process of joining metal by heating the base metal to a temperature above 800°F and adding a nonferrous filler metal that melts below the base metal. CADWELD is an exothermic welding, in which the filler metal is melt down by the exothermic oxidization of aluminium powder. Both are important to attach electrical cable for cathodic protection and lightening protection process. Testing Items and Testing Procedure Copper penetration 2 test specimens shall the sectioned transverse to the anode lead and 2 test specimens parallel with the anode…
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Cathodic Protection, Corrosion Test

Corrosion related surface defects for stainless steel

beatcorrosion March 6, 2016 0 Comments

Corrosion related surface defects for stainless steel Iron Contamination Iron contamination is probably the most significant corrosion related surface defect for stainless steel. The carbon steel particles can be easily picked up through steel lay yard, cutting, forming rolls, steel wire brushing, sand blasting, grinding. The embedded iron particles can form local galvanic cells and lead to pitting of stainless steel in moist atmosphere. Heat Tint Heat tint is developed in heat treatment process or welding process. The heat will produce heavy oxide films. For stainless steel application, most of scale is developed in the HAZ of weldment. The colour…
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Materials Selection

AC Corrosion

beatcorrosion December 12, 2015 0 Comments

AC corrosion became a known issue since more and more pipelines are sharing ROW with HVAC transmission lines. It is caused by the metal loss due to AC current leaving the pipeline. There are three different types of AC interference, which are the source of such AC current. Electrostatic Coupling This is also called capacitive interference. It may only happen to well insulated (not grounded) structure, e.g. above ground test station, pipeline near ditch or in stock yard Electromagnetic Coupling This is also called inductive interference. This is the most often seen AC interference mechanism, in which pipeline is acting…
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Cathodic Protection, Coatings, DCVG