Epoxy coated steel pipe is a product created by applying epoxy powder to the surface of a heated steel pipe via an electrostatic spraying process, followed by curing to form a continuous anti-corrosion layer. The coating bonds chemically with the steel pipe, offering excellent adhesion, corrosion resistance, and resistance to cathodic disbondment, while remaining highly compatible with cathodic protection systems. Xingbang manufactures a full range of epoxy-coated steel pipes (DN30–DN1600mm) to meet anti-corrosion requirements for buried and underwater pipelines.
Internal Anti Corrosion Layer Grades and Thicknesses
|
Coating Grade |
Minimum Thickness (μm) |
|
Standard Grade |
≥200 |
|
Reinforced Grade |
≥300 |
|
Extra-Reinforced Grade |
≥450 |
Core advantages of epoxy coated steel pipe
Strong adhesion; resistant to delamination
The epoxy powder chemically bonds with the steel pipe surface at high temperatures, achieving a cross-cut adhesion rating of 1–3; it resists peeling and delamination even during long-term underground burial or immersion in water.
01
Dense anti-corrosion layer; wide temperature range
Single-layer coating thickness is 300-500 μm, while dual-layer FBE can reach 625-1000 μm; suitable for temperatures ranging from -30°C to 100°C. The cured coating features a dense structure that effectively blocks the penetration of moisture, oxygen, and corrosive agents found in the soil.
02
Excellent compatibility with cathodic protection
The coating does not shield cathodic protection currents; cathodic disbondment (24h, 65°C) is ≤8 mm. It works in tandem with cathodic protection systems to mitigate the impact of minor coating defects, thereby enhancing overall anti-corrosion reliability.
03
Mechanical strength meets construction requirements
Impact strength at ambient temperature is ≥18 J, and the coating withstands a 3° bend without cracking. It endures mechanical stresses during transportation, backfilling, and crossing operations, making it suitable for diverse soil environments.
04
Environmentally friendly coating process; no solvent emissions
Utilizes 100% solid epoxy powder; the application process generates no VOCs, meeting green manufacturing standards and environmental requirements for overseas projects.
05
Quality Control
Key inspection items for epoxy coated steel pipe:
Coating Thickness
Non-destructive testing using a magnetic thickness gauge. Measurements are taken at three axial locations along the pipe, with four circumferential points per location. Single-layer FBE thickness must be 300–500 μm; double-layer FBE must be 625–1000 μm.
Holiday Detection (Spark Test)
100% inspection of every pipe using a high-voltage holiday detector. Test voltage is set at (coating thickness × 5 V/μm) to ensure the absence of pinholes or holidays.
Adhesion Test
The bond strength between the coating and the steel pipe is measured using the pull-off or cross-cut method; a result of ≥20 MPa or a rating of Grade 1–3 is generally required for compliance.
Cathodic Disbondment Test
The coating's resistance to disbondment is evaluated under conditions of 65°C, 24 hours, and -3.5 V; radial disbondment must not exceed 8 mm, serving to verify long-term anti-corrosion performance.
Mechanical Property Test
Impact resistance at ambient temperature must be ≥18 J, and the coating must show no cracking after a 3° bend test, confirming its ability to withstand stresses associated with transportation, backfilling, and soil conditions.
Appearance and Marking Inspection
Surface smoothness and color uniformity are inspected for every pipe; qualified products are marked with a traceable production code.
Applications
Epoxy coated steel pipes are widely used in long-distance oil and gas pipelines, municipal water supply projects, chemical and industrial piping, mining and power systems, and marine/subsea pipelines. They also serve as the carrier pipe for polyurethane-insulated piping systems.
FAQ
Q: What are the differences between FBE and 3PE coatings?
A: FBE offers strong adhesion, a wide temperature range (-30°C to 100°C), and compatibility with cathodic protection, though its resistance to mechanical scratching is relatively weak. 3PE adds an adhesive layer and an outer PE layer, providing superior resistance to impact and scratching, although its maximum operating temperature is lower (70°C). FBE is typically used for buried pipelines in stable soil conditions, whereas 3PE or dual-layer FBE is recommended for rocky terrain or sections crossing roads and rivers.
Q: How do I choose between single-layer and dual-layer FBE?
A: Single-layer FBE is suitable for standard buried pipelines in favorable environments. Dual-layer FBE features an increased coating thickness of 625–1000 µm, significantly enhancing impact and scratch resistance; it is specifically designed for challenging conditions such as rocky terrain, horizontal directional drilling (HDD) crossings, irregular elbows, and areas with high water tables.
Q: What precautions should be taken during storage and transport?
A: Pipe ends must be fitted with protective caps, and nylon slings must be used for loading and unloading. During storage, pipes should be placed on sleepers (dunnage) and covered to protect against rain and sunlight. For long-distance ocean transport, the use of frame containers or bulk carriers is recommended, with cushioning pads placed between the pipes.
Hot Tags: epoxy coated steel pipe, China epoxy coated steel pipe manufacturers, suppliers, factory, 3pe anti corrosion coating steel pipe , 3pe anti corrosion insulation steel pipe , 3pe anti corrosion steel pipe , 3pe anti corrosive steel pipe, external 3PE coated pipe, External FBE Coating Pipe