Coated steel pipe details

coated steel pipe requirements
the coating layer should be smooth and flat, free from scratches, cracks, pinholes, and adhesion of foreign matter and other defects. the outer coating of the steel pipe shall be red. there should be a clear and durable mark on the coated steel pipe, and the content of the mark should at least include: the product model, base pipe specification and wall thickness, implementation standard, name or trademark of the manufacturer, production date or batch number, etc.

coated steel pipe material
base pipe the material, specifications, and dimensions of the steel pipe used for coating shall comply with the provisions of gb/t3091 and gb/t8163. coating materials the epoxy resin powder used for coating shall comply with the relevant national standards or industry standards.

connection form of coated steel pipe
coated steel pipes with threaded, flanged, grooved connections, and bimetallic welding shall comply with the provisions of gb/t 7306.2, gb/t 9119, and gb5135.11.

the coating thickness of coated steel pipe
coating thickness should comply with the provisions of table 1. table 1 coating thickness nominal diameter dn mm coating thickness mm dn≤65>0.30 dn≥80>0.35 pinhole test requirements carry out the pinhole test according to the method specified in 6.3, and the coated steel pipe should have no electric sparks. adhesion requirements carry out the adhesion test according to the method specified in 6.4, and the adhesion of the coating should be grade 1-3. bending resistance perform a bending test according to the method specified in 6.5, and the coating should not fall off or break. anti-flattening performance the flattening test shall be carried out according to the method specified in 6.6, and the coating shall have no peeling or fracture. impact resistance the impact test shall be carried out according to the method specified in 6.7, and the coating shall not peel off or break. vacuum resistance performance carry out the vacuum test according to the method specified in 6.8, and the coating should not fall off. high-temperature resistance performance carry out the high-temperature test according to the method specified in 6.9, and the coating should have no falling off, swelling, cracking, peeling, or damage. low-temperature resistance performance carry out the low-temperature test according to the method specified in 6.10. the coating should not fall off or be damaged. after the test, the adhesion of the coating should meet the requirements of 5.6. pressure cycle the pressure cycle test shall be carried out according to the method specified in 6.11. the coating should not fall off or be damaged. after the test, the adhesion of the coating should meet the requirements of 5.6. temperature cycle the temperature cycle test shall be carried out according to the method specified in 6.12. the coating shall not fall off or be damaged. after the test, the adhesion of the coating shall meet the requirements of 5.6. warm water aging resistance carry out the warm water aging test according to the method specified in 6.13, and the coating should not fall off or be damaged. external surface properties the external surface of the coated steel pipe is coated with epoxy resin, which should meet the requirements of 5.4, 5.5, and 5.6. the outer surface of the coated steel pipe is a hot-dip galvanized layer, which shall comply with the relevant provisions of gb/t 3091. the outer surface of the coated steel pipe is coated with other anti-corrosion materials, which shall comply with the relevant national standards or industry standards.