Study on the Applicability of Hi-Lock Interference Socket Joints for Steel Pipelines

The integrity, thickness, and adhesion of the coating on the socket and socket parts of the pipe section after on-site service were tested using an endoscopy, non-destructive testing, and electric spark leak detector. The corrosion resistance, sealing integrity, and structural mechanical properties of the coating at the joint of the interference socket and socket steel pipeline were evaluated through impact tests, high-temperature and high-pressure corrosion simulation tests, hydraulic blasting tests, and finite element calculations. The results showed that the basic properties and mechanical properties of the coating at the joints of Hi-Lock interference socket joints were good. After on-site service, the surface of the Hi-Lock joint connection did not undergo corrosion failure and had good corrosion resistance. For interference socket pipe joints with an internal pressure of 4 MPa, calculation based on the mechanical modeling results showed that the axial tensile failure load was about 275 kN, the axial compression failure load was about 337 kN, and the concentrated bending moment failure load at the end was about 15.4 kN·m. The pipe section had good mechanical stability. The Hi-Lock interference socket joint met the relevant standards and design requirements of the oilfield site.