▎ 摘　　要

NOVELTY - Electric melting pipe fitting comprises an inner layer (41), a hydrogen blocking layer (1), a core pipe layer (2) and an outer protective layer (42) from inside to outside, where the material of the hydrogen blocking layer is polyamide resin composition. The polyamide resin composition contains 100 pts. wt. polyamide resin, 0.01-6 pts. wt. particulate inorganic compound, and 0.01-12 pts. wt. one molecule contains more than three hydroxyl groups or more than three amino groups, and the number average molecular weight manganese is less than 2000 of organic compound. The inner layer and the outer protective layer are integrated structure, the inner side of the inner layer is provided with an electric heating wire (43). The electric heating wire is located in the spiral groove at the inner side of the inner layer, the two ends of the electric melting pipe are respectively provided with a wiring hole (5) and an observation hole (6). USE - Electric melting pipe fitting used for high voltage composite pipeline in gas and water supply pipe network and for hydrogen conveying in starting stage. ADVANTAGE - The electric melting pipe fitting is easy to prepare and cost-effective, has excellent hydrogen resistance performance, hydrogen blocking property, hydrogen leakage prevention property and hydrogen embrittlement resistance, and durability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing an electric melting pipe fitting for high voltage composite pipeline, which involves: a. preparing graphene coating on the surface of the Monel alloy insert by spin coating technology, forming a core tube layer; b. winding the carbon fibre prepreg tape to the outer side of the core tube layer for heating and solidifying to form, forming a reinforcing layer; c. putting the assembly prepared into a mold, after preheating, injecting the polyamide resin composition into the mold and curing by an injection molding machine, forming a hydrogen blocking layer; d. putting the assembly prepared into an oven to preheat, taking out and putting into another set of mold, injecting the PE100-RC into the mold by an injection molding machine, forming an inner layer, an outer protective layer, an observation hole and a wiring hole; e. adjusting the state of the assembly prepared in the natural state, spirally cutting inner surface of the inner layer of the assembly, embedding the oxygen-free copper wire covered with glue in the spiral groove, using the hot air gun to heat the oxygen-free copper wire coated with glue on the inner layer; and f. checking the wiring of the assembly, after checking is qualified, mounting the wiring column in the wiring holes at two ends. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a fitting. 1Hydrogen blocking layer 2Core pipe layer 5Wiring hole 6Observation hole 41Inner layer 42Outer protective layer 43Electric heating wire 51Wiring column