Vad är sammansättningen och funktionen för 3PE-korrosionsskiktet?
The structure of 3PE is epoxy powder (bottom layer) + adhesive (middle layer) + polyethylene (surface layer), with a total thickness of>=2.5mm. Epoxy powder provides cathodic stripping protection (adhesion>=50N/cm), and polyethylene resists mechanical damage. This technology can Förläng livslängdens livslängd till 30 år . Kostnaden är 20% högre än för enskikts FBE, men kostnadsprestanda är bättre.
Varför används dubbelskikt FBE för ubåtens rörledning mot korrosion?
Double-layer fusion-bonded epoxy (FBE) includes anti-rust primer and impact-resistant topcoat, with a total thickness of 500-1000μm. Its seawater permeability resistance is better than 3PE, and it is easy to repair. With aluminum sacrificial anode (one group every 200 meters), the protection current density needs to be Greater än eller lika med 110 mA/m² .
Hur väljer jag antikorrosionsbeläggning i hög temperaturmiljö?
When the temperature is greater than 80℃, 3PE will be delaminated, and polyurethane foam (PUF) or glass flake coating will be used instead. Zinc silicate coating (temperature resistance 400℃) is commonly used in refinery pipelines. Before spraying, sandblasting is required to Sa2.5 level, and the anchor pattern depth is 50-75 μm.
Synergistisk effekt av katodiskt skydd och antikorrosionsbeläggning?
The coating reduces the cathodic protection current requirement by 90%, but the defects still require -0.85V (CSE) potential protection. The forced current system uses MMO/Ti anode, and the output current is<=30A. CIPS needs to be used regularly to detect the uniformity of the potential to avoid over-protection and coating skala .
Hur upptäcker man åldrandet av antikorrosionsskiktet i den avslappnade pipeline?
The DCVG (direct current voltage gradient) method is used to locate the coating damage point with an accuracy of ±0.3m. Infrared thermal imaging can detect delamination defects. Laboratory sampling is carried out for salt spray resistance test (5000 hours) and bending resistance test (radius of curvature>=25d).
