Abstract:
To address the design difficulty of 1 422 mm×1 219 mm tee used at stations along China–Russia Eastern Gas Pipeline under low temperature condition, the domestic and foreign pipe fitting standards were compared, and similar projects were investigated. A comprehensive study was carried out from the determination of design temperature, selection of materials, design of structural dimensions, establishment of Charpy impact toughness, etc., revealing that the minimum design temperature of fittings in the China–Russia Eastern Gas Pipeline is -45 ℃, and the material of tee is X80. The limit analysis design method in
Specification for high-test wrought butt-welding fittings (SY/T 0609-2016), is used to determine that the original thickness of the tee is 57 mm, and the length from the end of the tee branch pipe to the center line of main pipe is 1 090 mm. The Charpy impact test temperature is determined to be -45 ℃. The mean Charpy impact energy of tee weld and heat affected zone is not less than 50 J, and that of pipe body is not less than 60 J. The determination of technical indexes would serve as a basis for the formulation of technical conditions for the manufacture of tees at stations along China–Russia Eastern Gas Pipeline under low temperature condition. The design and manufacture of the new product has reached advanced level in the world.