PIPELINE-JOINT COATING MACHINE, CONSTRUCTION METHOD AND NOVEL PIPELINE-JOINT COATING STRUCTURE

摘要

Disclosed are a pipeline-joint coating machine, a construction method and a novel pipeline-joint coating structure. The machine comprises a metal liner plate (4), an electric heating apparatus (3) and a steel hoop (1) in sequence from inside to outside. The construction method comprises steps of: a. surface treatment; b. steel pipe preheating; c. primer painting; d. wrapping with a pipeline-joint coating sheet; e. wrapping the metal liner plate; f. wrapping the electric heating apparatus; g. wrapping and locking the steel hoop; h. programmed temperature control; and i. machine dismantling. The new pipeline-joint coating structure comprises a joint steel pipe (6), a corrosion protective coating (7) preformed at two ends, and a pipeline-joint coating part. An epoxy primer layer (8) is formed on the exterior wall of the steel pipe at the pipeline-joint coating part, a pipeline-joint coating sheet (5) is wrapped around the epoxy primer layer (8), and a metal liner plate (4) is disposed on the periphery of the pipeline-joint coating sheet (5). The pipeline-joint coating machine is simple and reliable. Locking the steel hoop to apply pressure can apply great pressure to the pipeline-joint coating sheet during the softening and adhesion process, thereby increasing the strength of adhesion with the epoxy primer layer. The peel strength reaches 250 N/cm or higher at 23°C and 100 N/cm or higher at 50°C, which are respectively 2 times and 5 times those obtained by using a heat shrink sleeve (stripe).