[article]
| Titre : |
Airport jet fuel piping lining issues |
| Type de document : |
texte imprimé |
| Auteurs : |
Rick A. Huntley, Auteur ; Cynthia O'Malley, Auteur |
| Année de publication : |
2018 |
| Article en page(s) : |
p. 12-16 |
| Langues : |
Américain (ame) |
| Catégories : |
Amines Une amine est un composé organique dérivé de l'ammoniac dont certains hydrogènes ont été remplacés par un groupement carboné. Si l'un des carbones liés à l'atome d'azote fait partie d'un groupement carbonyle, la molécule appartient à la famille des amides. Découvertes en 1849, par Wurtz les amines furent initialement appelées alcaloïdes artificiels.
On parle d'amine primaire, secondaire ou tertiaire selon que l'on a un, deux ou trois hydrogènes substitués.
Par exemple, la triméthylamine est une amine tertiaire, de formule N(CH3)3.
Typiquement, les amines sont obtenues par alkylation d'amines de rang inférieur. En alkylant l'ammoniac, on obtient des amines primaires, qui peuvent être alkylées en amines secondaires puis amines tertiaires. L'alkylation de ces dernières permet d'obtenir des sels d'ammonium quaternaire.
D'autre méthodes existent : 1. Les amines primaires peuvent être obtenues par réduction d'un groupement azoture, 2. Les amines peuvent aussi être obtenues par la réduction d'un amide, à l'aide d'un hydrure, 3. L'amination réductrice permet l'obtention d'amines substituées à partir de composés carbonylés (aldéhydes ou cétones), 4. Les amines primaires peuvent être obtenues par la réaction de Gabriel.
Analyse des défaillances (fiabilité)
Délaminage
Epoxydes
Expertises
Phénoplastes
Primaire (revêtement)
Revêtements -- Défauts:Peinture -- Défauts
Revêtements -- Détérioration:Peinture -- Détérioration
Tuyauterie
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
An international airport was in the midst of an expansion project. As part of the project, 24-inch-diameter jet fuel piping was being installed by a subcontractor hired by the general contractor that was directly hired by the owner to manage the project. The piping manufacturer installed both the interior and exterior linings. According to the specification, the interior of the pipes was required to be abrasive blast-cleaned to an SSPC-SP 10/NACE No. 2 Near-White Blast Cleaning finish. Additionally, according to the specification, “The standard required at the time of lining shall be a minimum of ISO 8501-1 grade Sa 2 1/2, with a surface profile of 70 ± 20 microns peak-to-trough height.
The coating system specified for application to the interior of the piping system was a phenolic lining. According to the product data sheet, the lining material was an amine-cured, modified epoxy-phenolic. The primer’s solids content was approximately 65 percent by volume and the finish coat’s solids content was approximately 63 percent. Both coats had a recommended dry film thickness of 100-to-150 microns per coat. The specification required that the coating be applied in two coats at a dry film thickness of 125 microns per coat. The first 50 mm of the ends of the pipes were required to be left bare.
The pipes were manufactured by a different company than the contracted company that was responsible for abrasive blast-cleaning and coating. After application of the interior coating, the pipes were transferred to a protected curing area. The interior of the curing area was heated with portable heaters.
The pipes were delivered to the jobsite at the airport in three lots, referred to as Lot 1, Lot 2 and Lot 3. During installation of the pipes, no additional preparation or coating was required to be performed at the welded seams. Sometime after the pipes were shipped to the jobsite, a number of the pipes in Lot 2 had been placed in trenches and were exposed to flooding conditions that partially or fully exposed the pipes to muddy water. Most of the pipes that were exposed to the floodwater were subsequently cleaned with fresh water to remove sand and other contaminants.
After the pipes had been exposed to the water, a video survey was performed to determine the condition of the interior coatings and to determine whether contaminants had been removed. It was discovered that the coating had blistered and delaminated in several areas. The delamination was most prevalent at the first several centimeters of the coating at the edges of the pipes. |
| Note de contenu : |
- Table : Pieces of pipe examined during field visit
- Fig. 1. Rust staining on the surface of the lining
- Fig. 2. An exudate is visible on the surface of the primer
- Fig. 3. Cracking pattern on primer consisting of traces of the gray topcoat
- Fig. 4. Good adhesion of the coating on Lot 1 pipe
- Fig. 5. Cracking pattern on topcoat and primer
- Fig. 6. Rust staining could be scraped away with a knife |
| En ligne : |
http://www.paintsquare.com/archive/index.cfm?fuseaction=view&articleid=6244 |
| Format de la ressource électronique : |
Web |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30372 |
in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL) > Vol. 35, N° 2 (02/2018) . - p. 12-16
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