Knowledge of seamless steel pipe for tubing material
1 Outer diameter and wall thickness
1.1 The nominal outer diameter of the steel pipe is 88.9mm, and the nominal wall thickness is 6.45mm.
1.2 The allowable deviation of the outer diameter and wall thickness of the steel pipe should meet the requirements of Table
1.3 Table Allowable deviation of outer diameter + 0.50mm －0.20mm Allowable deviation of wall thickness + 0.97mm －0.77mm
2 .The usual length of steel pipe is 9400mm～9750mm. After negotiation between the supplier and the buyer and indicated in the contract, steel pipes of other lengths can also be supplied.
3 Shape
3.1 The curvature of the steel pipe shall not be greater than 1.0mm/m.
3.2 The end faces of both ends of the steel pipe should be perpendicular to the axis of the steel pipe, and the cut burrs should be removed.
4 Weight Steel pipes are delivered according to actual weight or theoretical weight.
The theoretical weight of the steel pipe per meter is 13.115kg/m (the density of steel is 7.85kg/dm3).
5. The allowable deviation of the chemical composition of the finished steel pipe should meet the relevant regulations of GB/T 222. 6. Delivery status Steel pipes are delivered in hot rolled status.
7. Mechanical properties After proper heat treatment, the mechanical properties of the steel pipe should meet the requirements of N80 steel grade in API SPEC 5CT.
8. Compactness The steel pipes shall be subjected to eddy current testing one by one to check the compactness of the steel pipes. The diameter of the artificial defect through hole of the eddy current testing comparative sample is φ2.2mm±0.01mm.
9. Surface quality The surface quality of the steel pipe is in accordance with the surface quality requirements of N80 tubing in API SPEC 5CT. Inspection and test The acceptance rules of steel pipes are in accordance with GB/T 2102. Steel pipes are inspected and accepted by furnace. Packaging, marking and quality certificate The packaging, marking and quality certificate of the steel pipe shall meet the requirements of GB/T 2102. The weight of each bundle of steel pipes should not exceed 2 tons, and the surface of the steel pipes should be coated with anticorrosive oil. After negotiation between the supplier and the demander, and indicate in the contract, it can also be marked according to the agreement.
