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Q How to verify the safe delivery of anti-corrosion steel pipes?
A Protecting the coating is critical for anti-corrosion steel pipes. We ensure all pipe ends with plastic caps or metal cross braces, several straps of sufficient thickness are wrapped around the pipe to avoid the direct contract between pipes, lifting straps are equipped to avoid directly contact with pipe when loading and unloading on port.
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Q How to inspect the quality of anti-corrosion steel pipes?
A There are few core checks for anti-corrosion steel pipes.
1) visual inspection to identify surface defect like runs, cracks, bubbles,
2) DFT inspection by using magnetic gauge to inspect coating thickness,
3) holiday detection (ASTM G62, ISO 2746) by using spark tester to test invisible defects like pinholes, voids or holidays,
4) adhesion testing by two method pull-off adhesion test (ASTM D4541, ISO 4624) and cross-cut test (ASTM D3359),
5) impact resistance by drop tester (ASTM G14) is another one method to test the coating ability.
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Q What's the necessary processing step before applying anti-corrosion layer?
A In the coating industry, there is a famous rule “80% of coating failures are due to poor surface preparation”. Surface preparation including but not limit to degreasing, abrasive blasting, to achieve a required cleanliness level (typically Sa 2.5 per ISO 8501-1), and proper surface roughness (anchor profile) for coating adhesion.
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Q What’s the difference between 3LPP and 3LPE?
A 3LPP with outer layer material polypropylene, 3LPE with outer layer material polyethylene. Compared with 3LPE, 3LPP provide better and superior hardness, abrasion resistance, impact resistance, and hydrocarbon resistance at high temperature.
3LPE often applied on ambient temperature buried pipelines, refer standard ISO 21809-1, DIN 30670, CSA Z245.21, 3LPP often applied on high-temperature pipelines, sour service and offshore applications, refer standard ISO 21809-1, DIN 30678, CSA Z245.22.
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Q What’s the difference between hot-dip galvanized and pre-galvanized pipe?
A Hot-dip galvanized pipe is galvanized after fabrication by immersing the finished pipe in molten zinc, resulting in a thicker, uniform coating (45–85 µm), offering about 20-30 years lifespan, and typically complies with ASTM A123 or ASTM A53. Pre-Galvanized pipe is made from galvanized steel strip (10–25 µm) before forming, offering about 1-5 years lifespan.
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Q What anti-corrosion coating options are available for steel pipe or tube?
A The aim of applying anti-corrosion coating on steel pipe is to extend the service life and ensure suitability for specific construction environments, transported media, and operational applications. We offer various internal and external coatings including, FBE (Fusion Bonded Epoxy), 3LPP (3-Layer Polyethylene), 3LPE (3-Layer Polypropylene), galvanized, cement mortar, and metallic cladding.
