{"id":6934,"date":"2025-05-19T11:50:37","date_gmt":"2025-05-19T03:50:37","guid":{"rendered":"https:\/\/www.topfirefighting.com\/?p=6934"},"modified":"2025-05-19T18:38:13","modified_gmt":"2025-05-19T10:38:13","slug":"pipe-joint-solutions-butt-weld-socket-weld","status":"publish","type":"post","link":"https:\/\/www.topfirefighting.com\/nl\/pipe-joint-solutions-butt-weld-socket-weld\/","title":{"rendered":"Pipe Joint Solutions Butt Weld Socket Weld"},"content":{"rendered":"

I. Technical principle and structural design<\/strong><\/h2>\n

1. Butt welding<\/strong><\/h3>\n

Connection method: <\/b><\/strong>Align the end faces of the two pipes directly and fuse them by filling solder to form a continuous weld.<\/p>\n

Structural features:<\/b><\/strong><\/p>\n

    \n
  • The weld is consistent with the pipe wall thickness, there is no protruding structure, and the flow resistance is small.<\/li>\n
  • The groove (V-type, U-type or J-type) needs to be processed to ensure the penetration rate.<\/li>\n
  • Standard specification: ASME B16.25 specifies the dimensional tolerance and surface treatment requirements of the butt welding groove.<\/li>\n<\/ul>\n

    2. Socket welding<\/strong><\/h3>\n

    Connection method:<\/b><\/strong>\u00a0Insert the pipe into the pipe fitting with a socket (such as a valve or a tee), and weld the fillet weld along the outer edge of the pipe fitting.<\/p>\n

    Structural features:<\/b><\/strong><\/p>\n

      \n
    • There is a 1.6mm expansion gap between the pipe and the pipe fitting (ASME B31.3 requirement).<\/li>\n
    • The weld is located between the outer wall of the pipe and the socket of the pipe fitting to form a mechanical lock.<\/li>\n<\/ul>\n

      Standard specification: <\/b><\/strong>ASME B16.11 defines the pressure grade and size series of socket welding pipe fittings.<\/p>\n

      II<\/strong>. Comparison of process requirements and operation procedures<\/strong><\/h2>\n

      1. Butt welding construction process<\/strong><\/h3>\n

      Groove processing:<\/b><\/strong><\/p>\n

        \n
      • Use a groove machine to cut a V-shaped groove (angle 60\u00b0\u00b15\u00b0, blunt edge 1.6mm).<\/li>\n
      • Clean the oil and rust within 20mm of the inner and outer walls of the groove.<\/li>\n<\/ul>\n

        Assembly and spot welding:<\/b><\/strong><\/p>\n

          \n
        • Use a clamp to ensure that the concentricity deviation of the pipe is \u22641mm, and fix it at 3~4 spot welds.<\/li>\n<\/ul>\n

          Multi-layer welding:<\/b><\/strong><\/p>\n

            \n
          • The base welding adopts TIG process (argon purity \u226599.99%), and the filling welding and cover welding can be selected by SMAW or GMAW.<\/li>\n
          • The interlayer temperature is controlled at 150~250\u2103 (carbon steel) or \u2264150\u2103 (stainless steel).<\/li>\n<\/ul>\n

            Post-weld treatment:<\/b><\/strong><\/p>\n

              \n
            • Perform 100% radiographic testing (RT) or ultrasonic testing (UT) to eliminate unfused or pore defects.<\/li>\n<\/ul>\n

              2. Socket welding construction process<\/strong><\/h3>\n

              Pipeline pretreatment:<\/b><\/strong><\/p>\n

                \n
              • Cut the pipe to a length tolerance of \u00b10.8mm to ensure that the insertion depth meets the requirements.<\/li>\n<\/ul>\n

                Assembly and positioning:<\/b><\/strong><\/p>\n

                  \n
                • Insert the pipe into the socket of the pipe fitting, leaving a 1.6mm axial gap (to prevent thermal stress cracking).<\/li>\n<\/ul>\n

                  Fillet weld welding:<\/b><\/strong><\/p>\n

                    \n
                  • Use SMAW or GTAW process to weld 1~2 welds around the pipe mouth.<\/li>\n
                  • The height of the weld leg must be \u22651.09 times the pipe wall thickness (ASME B31.3 regulations).<\/li>\n<\/ul>\n

                    Inspection and acceptance:<\/b><\/strong><\/p>\n

                      \n
                    • Visual inspection (VT) to check the continuity of the weld, and perform penetration testing (PT) if necessary.<\/li>\n<\/ul>\n

                      III<\/strong>. Comparison of core performance and economic efficiency<\/strong><\/h2>\n\n\n\n\n\n\n\n\n\n
                      Indicator<\/td>\nButt Weld<\/td>\nSocket Weld<\/td>\n<\/tr>\n
                      Kracht<\/p>\n

                       <\/td>\n

                      		High (weld strength equals base material)<\/td>\nMedium (depends on fillet weld shear resistance)<\/p>\n

                       <\/td>\n<\/tr>\n

                      Sealing<\/p>\n

                       <\/td>\n

                      		Excellent (full penetration structure)<\/p>\n

                       <\/td>\n

                      		Good (depends on weld density)<\/p>\n

                       <\/td>\n<\/tr>\n

                      Applicable Pipe Diameter<\/p>\n

                       <\/td>\n

                      		DN15~DN2000<\/p>\n

                       <\/td>\n

                      		DN15~DN80 (advantage for small diameters)<\/p>\n

                       <\/td>\n<\/tr>\n

                      Installation Cost<\/p>\n

                       <\/td>\n

                      		High (requires groove machining, skilled welders)<\/p>\n

                       <\/td>\n

                      		Low (no groove required, easy operation)<\/p>\n

                       <\/td>\n<\/tr>\n

                      Maintenance Difficulty<\/p>\n

                       <\/td>\n

                      		High (requires cutting weld for repair)<\/p>\n

                       <\/td>\n

                      		Low (local repair welding possible)<\/p>\n

                       <\/td>\n<\/tr>\n

                      Applicable Pressure<\/p>\n

                       <\/td>\n

                      		High pressure (Class 1500~2500)<\/p>\n

                       <\/td>\n

                      		Medium and low pressure (Class 300~600)<\/p>\n

                       <\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

                      IV<\/strong>. Analysis of industry application scenarios<\/strong><\/h2>\n

                      1. Typical applications of butt welding<\/strong><\/h3>\n

                      Long-distance oil and gas pipelines:<\/b><\/strong><\/p>\n

                      Requirements:<\/b><\/strong>\u00a0withstand high pressure (\u226510MPa), resist hydrogen sulfide stress corrosion.<\/p>\n

                      Solution: <\/b><\/strong>X65 steel grade pipeline + U-shaped groove, multi-pass welding with post-weld heat treatment (PWHT).<\/p>\n

                      Nuclear power main steam pipeline:<\/b><\/strong><\/p>\n

                      Requirement:<\/b><\/strong>\u00a0zero leakage, thermal fatigue resistance.<\/p>\n

                      Solution: <\/b><\/strong>Austenitic stainless steel + automatic orbital welding, 100% radiographic flaw detection.<\/p>\n

                      2. Typical applications of socket welding<\/strong><\/h3>\n

                      Chemical instrument pressure pipe:<\/b><\/strong><\/p>\n

                      Requirement: <\/b><\/strong>small pipe diameter (DN15~25), easy to disassemble and calibrate.<\/p>\n

                      Solution: <\/b><\/strong>316L stainless steel socket welding valve + gas shielded welding of fillet weld.<\/p>\n

                      Ship ballast water system:<\/b><\/strong><\/p>\n

                      Requirement:<\/b><\/strong>\u00a0fast installation, vibration resistance.<\/p>\n

                      Solution: <\/b><\/strong>galvanized steel pipe with socket welding flange, epoxy anti-corrosion coating after welding.<\/p>\n

                      V. Key factors for selection decision<\/strong><\/h2>\n

                      System pressure and temperature:<\/b><\/strong><\/p>\n

                        \n
                      • High pressure and high temperature (P\u22655MPa, T\u2265200\u2103) give priority to butt welding.<\/li>\n
                      • Medium and low pressure and normal temperature systems can consider socket welding to reduce costs.<\/li>\n<\/ul>\n

                        Pipe diameter and space restrictions:<\/b><\/strong><\/p>\n

                          \n
                        • When the pipe diameter is below DN80 and the installation space is narrow, socket welding is easier to operate.<\/li>\n
                        • For large pipe diameters (\u2265DN150), butt welding must be used to ensure structural strength.<\/li>\n<\/ul>\n

                          Maintenance and inspection requirements:<\/b><\/strong><\/p>\n

                            \n
                          • For pipelines that need to be frequently disassembled and repaired (such as sampling systems), socket welding is more economical.<\/li>\n
                          • For pipelines involving highly toxic or radioactive media, the full penetration structure of butt welding is safer.<\/li>\n<\/ul>\n

                            VI. Common problems and solutions<\/strong><\/h2>\n

                            1. Typical defects of butt welding<\/strong><\/h3>\n

                            Incomplete penetration:<\/b><\/strong>\u00a0adjust the groove angle or increase the welding current to ensure root fusion.<\/p>\n

                            Heat-affected zone cracks:<\/b><\/strong>\u00a0control the interlayer temperature, slow cooling after welding or perform stress relief heat treatment.<\/p>\n

                            2. Typical defects of socket welding<\/strong><\/h3>\n

                            Insufficient gap:<\/b><\/strong>\u00a0check with a feeler gauge before installation to ensure a 1.6mm expansion gap.<\/p>\n

                            The weld is not filled:<\/b><\/strong>\u00a0increase the number of welds or use a larger diameter electrode.<\/p>\n

                            VII<\/strong>. Industry standards and compliance requirements<\/strong><\/h2>\n

                            ASME B31.3:<\/b><\/strong>\u00a0specifies the process assessment and inspection standards for butt welding and socket welding.<\/p>\n

                            API 570:<\/b><\/strong>\u00a0requires wall thickness inspection of butt-welded pipes every 5 years, and socket welding needs to focus on checking the corrosion of fillet welds.<\/p>\n

                            ISO 15614-1:<\/b><\/strong>\u00a0Certification requirements for welding procedure specifications (WPS).<\/p>\n

                            VIII<\/strong>. Future development trends<\/strong><\/h2>\n

                            Automated welding:<\/b><\/strong>\u00a0Robotic butt welding system improves the construction efficiency of large-diameter pipes with an accuracy of \u00b10.2mm.<\/p>\n

                            Argon-free technology:<\/b><\/strong>\u00a0Flux-Cored Wire reduces the reliance on gas protection during butt welding.<\/p>\n

                            Intelligent detection:<\/b><\/strong>\u00a0AI-driven real-time weld quality monitoring system (such as Olympus OmniScan X3).<\/p>","protected":false},"excerpt":{"rendered":"

                            I. Technical principle and structural design 1. Butt welding Connection method: Align the end faces of the two pipes directly and fuse them by filling solder to form a continuous weld. Structural features: The weld is consistent with the pipe wall thickness, there is no protruding structure, and the flow resistance is small. The groove […]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1,22],"tags":[],"class_list":["post-6934","post","type-post","status-publish","format-standard","hentry","category-news","category-technology"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.topfirefighting.com\/nl\/wp-json\/wp\/v2\/posts\/6934","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.topfirefighting.com\/nl\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.topfirefighting.com\/nl\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.topfirefighting.com\/nl\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.topfirefighting.com\/nl\/wp-json\/wp\/v2\/comments?post=6934"}],"version-history":[{"count":0,"href":"https:\/\/www.topfirefighting.com\/nl\/wp-json\/wp\/v2\/posts\/6934\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.topfirefighting.com\/nl\/wp-json\/wp\/v2\/media?parent=6934"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.topfirefighting.com\/nl\/wp-json\/wp\/v2\/categories?post=6934"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.topfirefighting.com\/nl\/wp-json\/wp\/v2\/tags?post=6934"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}