EP-coated PE plastic steel pipe is a product that uses PE (modified polyethylene) for hot-dipped plastic coating or EP (epoxy resin) for internal and external coating, featuring excellent corrosion resistance. The coating itself also boasts good electrical insulation properties and does not cause electrolytic erosion. It has low water absorption, high mechanical strength, and a small friction coefficient, ensuring long-term use. It also effectively prevents damage from plant root systems and soil environmental stresses.
Features: It boasts corrosion and rust resistance, being made from an epoxy resin coated spiral steel pipe factory, and its inner wall is extremely smooth with low friction resistance, suitable for piping of edible oils or drinking water. Moreover, the outer wall of the pipe can be painted in bright colors for enhanced aesthetics. Compared to traditional pipes that are brittle or prone to rust, the lifespan of plastic-coated steel pipes can reach over 20 years, making them cost-effective in total price. They are more economical than copper pipes, galvanized pipes, and stainless steel pipes, etc. Therefore, they are not only used for domestic water supply pipes but also for municipal pipelines in cities, such as natural gas and oil pipelines. Plastic-coated steel pipes, while maintaining the hardness of traditional steel pipes, are also lighter, have less internal resistance, and allow for faster flow rates.
1. Appearance inspection
Visually inspect the appearance quality of coated steel pipes; the test results should comply with the provisions of 5.1.
2. Thickness Measurement
Take two cross-sections of different lengths from both ends of the coated steel pipe, measure the coating thickness at any four points on the circumference intersecting each other on each cross-section using an electromagnetic thickness gauge. The test results shall comply with the provisions of 5.4.
3. Pinhole Test
The pipe section specimen is approximately 1000mm in length. The steel pipe coating is inspected under specified test voltages using an electric spark leak detector. The coating thickness should not exceed 0.4mm, with the test voltage set at 1500V. For coating thicknesses greater than 0.4mm, the test voltage is 2000V. Check for the presence of electric sparks, and record the test results.
Should comply with Regulation 5.5.
4. Adhesion Test
The adhesion test is conducted according to 7.4.2 of CJ/T 120-2008, and the test results should comply with the provisions of 5.6.
5. Bend Test
Bend tests are conducted on coated steel pipes with an outside diameter of DN≤50mm. The length of the pipe specimens is (1200±100)mm.
At an ambient temperature of (20±5)°C, bend the pipe with a curvature radius eight times the nominal bore diameter, at an angle of 30°, using a bending machine or mold. During the bending test, the pipe is without any filling inside, and the weld is positioned on the side of the bending main surface.
After testing, the specimen is cut open from the middle of the curved arc, inspect the inner coating, and the test results should comply with the provisions of 5.7.
