Insulation joints are mainly used in the sealing protection of oil and gas pipelines and to prevent electrochemical corrosion. They are mainly composed of short joints, steel flanges, fixing rings, seals, insulation plates, insulation sleeves and filling insulation materials. Seals can be O-ring seal, U-ring seal and “O-shaped + U-shaped” composite seal, although the sealing structure is different, but they have the same sealing principle. Its sealing principle is: the sealing ring under the action of the external preload to produce elastic deformation and the sealing force required to ensure that the medium in the pipeline is not leakage. The following is an example of X80 DN1200 PN120 insulated joint to illustrate its welding process.<\/p>\n\n\n\n
The material of the insulating joint in this experiment is API 5L X80, and the size is 1 219mm\u00d727.5mm. The main body pressure forging steel (flange, fixed ring) material is F65, \u2163 class; The sealing part is fluorine rubber U-shaped sealing ring, which has the characteristics of reliable sealing, low water absorption, high compressive strength, good elasticity and electrical insulation. Insulation plate material has strong electrical insulation performance, resistance to fluid penetration and low water absorption. Forged flange in accordance with ASTM A694 for F65 C, Mn, P, S content and carbon equivalent, crack resistance index, hardness and impact energy requirements. After testing, the metallographic structure is pearlite + ferrite, uniform structure, no segregation, the average grain size is 8 grade. The finer grain size ensures the high strength and toughness of the forgings.<\/p>\n\n\n\n
Welding procedure qualification<\/strong><\/p>\n\n\n\n F\u00fcr das Schwei\u00dfen dieses Produkts, nach Spannungsabbau Behandlung, Zug-, Biege-, Schlag-, H\u00e4rte-, Metallographie-und Spektralanalyse Tests, die Ergebnisse entsprechen den Spezifikationen.<\/p>\n\n\n\n 1. Schwei\u00dfnaht<\/p>\n\n\n\n 2. Verfahren zum Schwei\u00dfen<\/p>\n\n\n\n The “argon arc welding backing + submerged arc welding filling and covering” of welding method. According to the selection principle of welding materials for high alloy steels with different steel grades stipulated in the pressure vessel welding code and standard, the welding materials matching with the grade of F65 steel were selected, which could not only ensure the strength requirements of F65 and X80 material, but also have good toughness.<\/p>\n\n\n\n Flansch-Nippel-Schwei\u00dfen<\/p>\n\n\n\n Flansche und Rohrverbindungen werden durch Argonlichtbogenschwei\u00dfen und automatisches Unterpulverschwei\u00dfen geschwei\u00dft. Argon-Lichtbogenschwei\u00dfen f\u00fcr das Gegenschwei\u00dfen und dann automatisches Unterpulverschwei\u00dfen f\u00fcr das F\u00fcll- und Deckschwei\u00dfen.<\/p>\n\n\n\n 1. Welding equipment.<\/p>\n\n\n\n Subsubmerged arc automatic welding machine: speed 0.04 ~ 2r\/min, workpiece clamping range \u03a6330 ~ \u03a62 700mm, the maximum length of the weldable workpiece 4 500mm, the maximum welding seam depth 110mm, can bear the weight of 30t.<\/p>\n\n\n\n Das Unterpulverschwei\u00dfen hat die Vorteile einer zuverl\u00e4ssigen Schwei\u00dfnahtqualit\u00e4t, einer sch\u00f6nen Schwei\u00dfraupenbildung und einer hohen Abschmelzleistung und kann in gro\u00dfem Umfang f\u00fcr Isolierverbindungen mit gro\u00dfem Durchmesser, f\u00fcr vollverschwei\u00dfte versenkte Kugelh\u00e4hne usw. verwendet werden.<\/p>\n\n\n\n (2) Welding method.<\/p>\n\n\n\n GTAW+SAW-Schwei\u00dfverfahren. Zun\u00e4chst verwenden wir Argon-Lichtbogenschwei\u00dfen Wurzel Hintergrund und F\u00fcllung jedes Mal, um sicherzustellen, dass die Wurzel durchschmelzen, und dann mit untergetauchten Lichtbogen automatische Mehrschicht-Multi-Pass-Schwei\u00dfen Methode zur vollst\u00e4ndigen F\u00fcllung und Abdeckung.<\/p>\n\n\n\n W\u00e4rmebehandlung nach dem Schwei\u00dfen<\/p>\n\n\n\n In order to reduce the residual stress of the weld and prevent the weld from cracking or stress deformation, it is necessary to de-stress and tempering after welding. SCD type rope electric heater (18.5m long) and LWK-3\u00d7220-A type temperature control box are used for heat treatment. K-type armored thermocouple is selected as temperature measuring equipment. The heat treatment temperature was 550\u2103, and the heat preservation time was 2hour.<\/p>\n\n\n\n The material of the insulating joint in this experiment is API 5L X80, and the size is 1 219mm\u00d727.5mm. The main body pressure forging steel (flange, fixed ring) material is F65, \u2163 class; The sealing part is fluorine rubber U-shaped sealing ring, which has the characteristics of reliable sealing, low water absorption, high compressive strength, good elasticity and electrical insulation. Insulation plate material has strong electrical insulation performance, resistance to fluid penetration and low water absorption. Forged flange in accordance with ASTM A694 for F65 C, Mn, P, S content and carbon equivalent, crack resistance index, hardness and impact energy requirements. After testing, the metallographic structure is pearlite + ferrite, uniform structure, no segregation, the average grain size is 8 grade. The finer grain size ensures the high strength and toughness of the forgings.<\/p>\n\n\n\n Welding procedure qualification<\/p>\n\n\n\n F\u00fcr das Schwei\u00dfen dieses Produkts, nach Spannungsabbau Behandlung, Zug-, Biege-, Schlag-, H\u00e4rte-, Metallographie-und Spektralanalyse Tests, die Ergebnisse entsprechen den Spezifikationen.<\/p>\n\n\n\n 1. Schwei\u00dfnaht<\/p>\n\n\n\n 2. Verfahren zum Schwei\u00dfen<\/p>\n\n\n\n The “argon arc welding backing + submerged arc welding filling and covering” of welding method. According to the selection principle of welding materials for high alloy steels with different steel grades stipulated in the pressure vessel welding code and standard, the welding materials matching with the grade of F65 steel were selected, which could not only ensure the strength requirements of F65 and X80 material, but also have good toughness.<\/p>\n\n\n\n Flansch-Nippel-Schwei\u00dfen<\/p>\n\n\n\n Flansche und Rohrverbindungen werden durch Argonlichtbogenschwei\u00dfen und automatisches Unterpulverschwei\u00dfen geschwei\u00dft. Argon-Lichtbogenschwei\u00dfen f\u00fcr das Gegenschwei\u00dfen und dann automatisches Unterpulverschwei\u00dfen f\u00fcr das F\u00fcll- und Deckschwei\u00dfen.<\/p>\n\n\n\n 1. Welding equipment.<\/p>\n\n\n\n Subsubmerged arc automatic welding machine: speed 0.04 ~ 2r\/min, workpiece clamping range \u03a6330 ~ \u03a62 700mm, the maximum length of the weldable workpiece 4 500mm, the maximum welding seam depth 110mm, can bear the weight of 30t.<\/p>\n\n\n\n Das Unterpulverschwei\u00dfen hat die Vorteile einer zuverl\u00e4ssigen Schwei\u00dfnahtqualit\u00e4t, einer sch\u00f6nen Schwei\u00dfraupenbildung und einer hohen Abschmelzleistung und kann in gro\u00dfem Umfang f\u00fcr Isolierverbindungen mit gro\u00dfem Durchmesser, f\u00fcr vollverschwei\u00dfte versenkte Kugelh\u00e4hne usw. verwendet werden.<\/p>\n\n\n\n (2) Welding method.<\/p>\n\n\n\n GTAW+SAW-Schwei\u00dfverfahren. Zun\u00e4chst verwenden wir Argon-Lichtbogenschwei\u00dfen Wurzel Hintergrund und F\u00fcllung jedes Mal, um sicherzustellen, dass die Wurzel durchschmelzen, und dann mit untergetauchten Lichtbogen automatische Mehrschicht-Multi-Pass-Schwei\u00dfen Methode zur vollst\u00e4ndigen F\u00fcllung und Abdeckung.<\/p>\n\n\n\n W\u00e4rmebehandlung nach dem Schwei\u00dfen<\/p>\n\n\n\n In order to reduce the residual stress of the weld and prevent the weld from cracking or stress deformation, it is necessary to de-stress and tempering after welding. SCD type rope electric heater (18.5m long) and LWK-3\u00d7220-A type temperature control box are used for heat treatment. K-type armored thermocouple is selected as temperature measuring equipment. The heat treatment temperature was 550\u2103, and the heat preservation time was 2h.<\/p>\n\n\n\n <\/p>","protected":false},"excerpt":{"rendered":" Isoliermuffen werden haupts\u00e4chlich f\u00fcr den Dichtungsschutz von \u00d6l- und Gaspipelines und zum Schutz vor elektrochemischer Korrosion verwendet. Sie bestehen haupts\u00e4chlich aus kurzen Muffen, Stahlflanschen, Befestigungsringen, Dichtungen, Isolierplatten, Isoliermuffen und F\u00fcllisoliermaterialien. Bei den Dichtungen kann es sich um O-Ring-Dichtungen, U-Ring-Dichtungen und \"O-f\u00f6rmige + U-f\u00f6rmige\" Verbunddichtungen handeln, wobei die Dichtungsstruktur [...]<\/p>","protected":false},"author":1,"featured_media":3612,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"yoast_head":"\n