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During offshore pipe-lay, pipe lengths with anticorrosion coating are welded together, and, to facilitate the welding process, the ends of the pipe remain uncoated. A wide range of field joint coating (FJC) types is available for coating this bare section, functioning in conjunction with the pipeline cathodic protection system to provide an anti-corrosion system or package. This paper aims to relate to two-layer type heat shrink sleeves (2LHSS), which commonly are used for FJC of concrete-weighted offshore pipelines where the sleeve typically is over-coated with a solid or foam type polyurethane “infill”. Similar sleeves also are used sometimes in exposed conditions on lines without concrete over-coating. The maximum allowable soluble salt contamination prior to application of high-performance coating systems can vary, depending upon the coating type, but typically has been set at 20 mg/m2 (de la Fuente et al., 2006). The first layer of three-layer heat shrink sleeve (3LHSS) systems for pipeline FJC, liquid epoxy, falls into this category (ISO_21809-3:2008, 2008). In contrast, the 2LHSS system does not use a liquid epoxy first layer but relies instead on the bonding of a “mastic” layer directly to the pipe metal surface. The maximum acceptable concentration of salt contamination on prepared metal surfaces prior to the application of 2LHSS has been a subject of debate and was the focus of this study. International standards for FJC do not provide a maximum salt level. However, some companies have continued to specify low thresholds for the maximum allowable salt level for 2LHSS, which can result in expensive delays in production during offshore pipe-lay. In this study, salt contamination levels of up to 120 mg/m2 were found to have no effect on peeling performance after accelerated aging by hot water immersion. Furthermore, preparation for welding and the use of potable water during ultrasonic testing procedures prior to FJC, typically reduces the salt contamination level to below 50 mg/m2 providing a strong case for the deletion of salt contamination testing for 2LHSS.

The potential risk of failure of the coating due to poor surface cleanliness/contamination was assessed by testing the adhesion between the coating and the steel substrate to which the coating is adhering, following a period of hot water immersion. Compliance with ISO 21809-3 “Annex I” requires 28 days’ immersion at maximum operating temperature. For this study, to create a severe situation, the test rings were subjected to accelerated aging by water immersion at the HSS upper specified temperature of 65°C for more than twice the specified period (ISO_21809-3:2008, 2008). Two HSS were tested; one was widely used in applications where exposure to moderate mechanical stress is required, having a high shear strength type mastic “hybrid” adhesive containing a significant proportion of amorphous polypropylene blended with tackifiers and ethylene vinyl acetate (EVA), Andrenacci et al. (2009) referred to as “Type A”. The second, referred to as “Type B”, is widely used in applications where it is covered by a layer of “infill”, typically consisting of polyurethane foam or solid polyurethane elastomer, i.e. typical design methodology for concrete coated pipelines. “Type B” HSS had a more moderate strength traditional type mastic than “Type A” containing a significant percentage of butyl rubber with asphalt, activation agents and tackifying resins. To determine how to apply the salt contamination without causing flash rust, a mini-study was completed on the steel substrate. After numerous trials, it was found impossible to not to form visible rust on the pipe surface. The extent of rusting was minimised by heating the pipe immediately after the application of the salt solution.

High levels of sea salt on power tool prepared pipe surfaces were investigated by peel testing of 2LHSS after hot water immersion and compared against peel tests undertaken prior to hot water immersion. The test conditions were considered severe: salt contamination levels of up to 120 mg/m2 applied on power tool cleaned pipe surfaces that had been aged for one year without prior grit blasting. The accelerated ageing procedure had twice the specified (ISO_21809-3:2008, 2008) water immersion duration, and the test samples had exposed edges providing the possibility for moisture to creep under the coating. The test results showed that there were no noticeable deleterious effects on the performance of the two most commonly used FJCs, 2LHSS. Therefore, it was concluded that, as the level of salt contamination on prepared pipe surfaces after wet non-destructive testing typically is much lower than the levels tested in this study, pipe surfaces prepared for the application of 2LHSS type do not require specific additional measures to further reduce salt contamination, provided that care is taken to ensure that these conditions are maintained consistently during pipe laying operations.

The frequency of salt contamination testing of power tool cleaned surfaces prior to mastic type heat shrink sleeves can be minimised, and perhaps omitted entirely, provided the above criteria are satisfied.

A literature review revealed there was little published information on the testing of 2LHSS and nothing related to hot water immersion testing. Hence, the results of this investigation have provided useful industrial data regarding the effect of hot water ageing and the influence of surface salt contamination on field joint corrosion prevention capabilities.

From November 29 to December 2 the Empire Hall at Olympia, London, will be given over to what will probably be the world's largest display of products, processes and services for use in the prevention or limitation of corrosion. Over 120 stands will be shared by 94 exhibitors, each contributing in some way or in many ways to this cause. The extensive preview in the following pages is divided into sections. However, the grouping is general and reflects only one aspect of a company's activities. Therefore a complete examination of items is recommended.

Historically, man's efforts to resist the effects of corrosion can be traced back several hundred years. Sir Hugh Platt (1552–1611) noted that an ‘oily substance’ prevented iron work rusting. The famous Dr. Angus Smith (1817–1884) patented a technique for coating heated metal pipes with ‘coal oil’ to resist corrosion. We have in the above some of the fundamental requirements of a coating, namely: 1. Surface preparation, aiming to clean the pipe surfaces of corrosion products, moisture and foreign matter. 2. Material having a water‐resistant quality.

Shows how observations (1993‐1999) and on‐site and laboratory measurements (1993‐1996) have made it possible to define certain prevalent parameters concerning AC corrosion risks. These are from the evaluation and prevention of AC corrosion risks as practised by Gaz de France.

The end of this month will see Britain's biggest display of products and processes designed to prevent the onset of corrosion in all its forms. At the Royal Horticultural Society's New Hall, in Westminster, there will be over a hundred stands on view to visitors to the Exhibition which will run from April 27 to 30 inclusive. Here is C.T.'s exclusive preview. Stand descriptions are grouped under various headings, but the fact that a firm's exhibits are described under one heading does not necessarily mean that its interests are confined solely to that group of products. The grouping of exhibitors in this preview is merely intended to facilitate visitors who are interested in particular aspects of corrosion prevention.

The purpose of this paper is to obtain a better insight into the impact of atmospheric corrosion in Mauritius by investigating the corrosion prevention strategies used in the country and determining the related costs.

Companies and organizations, in various industrial sectors, affected by atmospheric corrosion were selected. They were inspected and surveys were performed in order to fulfill the aim of the study.

It has been observed that extensive atmospheric corrosion problems have been encountered in the capital city, leading to the use of a range of corrosion prevention methods. However, carbon steel, which corrodes easily, is very commonly used in the country. This leads to the wide use of alkyd‐based barrier coatings. The cost of atmospheric corrosion has been found to be equal to 0.38 per cent of the GDP.

This study is expected to raise concern on the problem of atmospheric corrosion in Mauritius and the related waste in materials.

This study is expected to help in adopting corrosion prevention policies and strategies in Mauritius.

Introduction Corrosion has been described as one of the scourges of civilisation. It would appear to be almost a universal phenomenon occurring in the home, on the roads—particularly in road vehicles—in the factory, on the farm, in vessels at sea, in aircraft in the sky, and in pipelines underground. Corrosion is not confined to metallic materials—although they are the major victims—in that stone, brickwork and concrete are also subject to corrosive attack. In Britain alone the annual cost of corrosion has been calculated to be over £600 million in materials replacement, maintenance costs and lost production; the annual world cost has been estimated as at least £10,000 million.

I am delighted that the fifth Corrosion and Metal Finishing Exhibition has been brought to Leeds and I congratulate the sponsors and exhibitors on their decision to stage this Exhibition in the heart of the industrial north.

There is a paramount need in process plant for effective control of corrosion. Corrosion can contaminate the product handled, cause unsafe conditions to develop or cause pollution if a vessel or pipeline leaks or collapses. Viewed in a positive light, efficient corrosion prevention can lead to economic plant life, a reduction in downtime for plant replacement, a good product and a safer working environment.