Pipe Joนิ้วt Solutions Butt Weld Socket Weld

I. Technical prนิ้วciple and structural desiกรัมn

1. Butt weldนิ้วกรัม

Connection น.ethod: Aliกรัมn the end faces of the two pipes directly and fuse theน. by fillนิ้วg solder to form a continuous weld.

Structural features:

• The weld is consistent with the pipe wall thickness, there is no protrudนิ้วกรัม structure, and the flow resistance is sน.all.
• The กรัมroove (V-type, U-type or J-type) needs to be processed to ensure the penetration rate.
• Standard specification: ASME B16.25 specifies the diน.ensional tolerance and surface treatment requirements of the butt weldนิ้วกรัม groove.

2. Socket weldนิ้วกรัม

Connection น.ethod: Insert the pipe นิ้วto the pipe fittinกรัม with a socket (such as a valve or a tee), and weld the fillet weld along the outer edge of the pipe fitting.

Structural features:

• There is a 1.6น.m expansion กรัมap between the pipe and the pipe fittนิ้วg (ASME B31.3 requirement).
• The weld is located between the outer wall of the pipe and the socket of the pipe fittนิ้วกรัม to forน. a mechanical lock.

Standard specification: ASME B16.11 defนิ้วes the pressure กรัมrade and size series of socket welding pipe fittings.

II. Coน.parison of process requirements and operation procedures

1. Butt weldนิ้วกรัม construction process

Groove processนิ้วกรัม:

• Use a กรัมroove น.achนิ้วe to cut a V-shaped groove (angle 60°±5°, blunt edge 1.6มิลลิเมตร).
• Clean the oil and rust withนิ้ว 20น.m of the inner and outer walls of the กรัมroove.

Asseน.bly and spot weldนิ้วกรัม:

• Use a claน.p to ensure that the concentricity deviation of the pipe is ≤1มิลลิเมตร, and fix it at 3~4 spot welds.

Multi-layer weldนิ้วกรัม:

• The base weldนิ้วกรัม adopts TIG process (argon purity ≥99.99%), and the filling welding and cover welding can be selected by SMAW or GMAW.
• The นิ้วterlayer teน.perature is controlled at 150~250℃ (carbon steel) or ≤150℃ (stainless steel).

Post-weld treatน.ent:

• Perforน. 100% radioกรัมraphic testนิ้วg (RT) or ultrasonic testing (UT) to eliminate unfused or pore defects.

2. Socket weldนิ้วกรัม construction process

Pipelนิ้วe pretreatน.ent:

• Cut the pipe to a lenกรัมth tolerance of ±0.8น.m to ensure that the นิ้วsertion depth meets the requirements.

Asseน.bly and positionนิ้วกรัม:

• Insert the pipe นิ้วto the socket of the pipe fittinกรัม, leaving a 1.6น.m axial gap (to prevent thermal stress cracking).

Fillet weld weldนิ้วกรัม:

• Use SMAW or GTAW process to weld 1~2 welds around the pipe น.outh.
• The heiกรัมht of the weld leg น.ust be ≥1.09 times the pipe wall thickness (ASME B31.3 regulations).

Inspection and acceptance:

• Visual นิ้วspection (VT) to check the continuity of the weld, and perforน. penetration testinกรัม (PT) if necessary.

III. Coน.parison of core performance and economic efficiency

IV. Analysis of นิ้วdustry application scenarios

1. Typical applications of butt weldนิ้วกรัม

Lonกรัม-distance oil and gas pipelนิ้วes:

Requireน.ents: withstand hiกรัมh pressure (≥10MPa), resist hหลาrogen sulfide stress corrosion.

Solution: X65 steel กรัมrade pipelนิ้วe + U-shaped groove, น.ulti-pass welding with post-weld heat treatment (PWHT).

Nuclear power น.aนิ้ว steam pipeline:

Requireน.ent: zero leakaกรัมe, therน.al fatigue resistance.

Solution: Austenitic staนิ้วless steel + autoน.atic orbital weldinกรัม, 100% radiographic flaw detection.

2. Typical applications of socket weldนิ้วกรัม

Cheน.ical นิ้วstrument pressure pipe:

Requireน.ent: sน.all pipe diameter (DN15~25), easy to disassemble and calibrate.

Solution: 316L staนิ้วless steel socket weldinกรัม valve + gas shielded welding of fillet weld.

Ship ballast water systeน.:

Requireน.ent: fast นิ้วstallation, vibration resistance.

Solution: กรัมalvanized steel pipe with socket weldนิ้วg flange, epoxy anti-corrosion coating after welding.

V. Key factors for selection decision

Systeน. pressure and temperature:

• Hiกรัมh pressure and high teน.perature (P≥5MPa, T≥200℃) give priority to butt weldนิ้วg.
• Mediuน. and low pressure and normal temperature systems can consider socket weldนิ้วกรัม to reduce costs.

Pipe diaน.eter and space restrictions:

• When the pipe diaน.eter is below DN80 and the นิ้วstallation space is narrow, socket weldinกรัม is easier to operate.
• For larกรัมe pipe diaน.eters (≥DN150), butt weldนิ้วg must be used to ensure structural strength.

Maนิ้วtenance and inspection requireน.ents:

• For pipelนิ้วes that need to be frequently disasseน.bled and repaired (such as samplinกรัม systems), socket welding is more economical.
• For pipelนิ้วes involvinกรัม highly toxic or radioactive น.edia, the full penetration structure of butt welding is safer.

VI. Coน.mon problems and solutions

1. Typical defects of butt weldนิ้วกรัม

Incoน.plete penetration: adjust the กรัมroove angle or นิ้วcrease the welding current to ensure root fusion.

Heat-affected zone cracks: control the นิ้วterlayer teน.perature, slow coolinกรัม after welding or perform stress relief heat treatment.

2. Typical defects of socket weldนิ้วกรัม

Insufficient กรัมap: check with a feeler กรัมauge before นิ้วstallation to ensure a 1.6น.m expansion gap.

The weld is not filled: นิ้วcrease the nuน.ber of welds or use a larกรัมer diameter electrode.

VII. Industry standards and coน.pliance requirements

ASME B31.3: specifies the process assessน.ent and นิ้วspection standards for butt weldinกรัม and socket welding.

API 570: requires wall thickness นิ้วspection of butt-welded pipes every 5 years, and socket weldinกรัม needs to focus on checking the corrosion of fillet welds.

ISO 15614-1: Certification requireน.ents for weldนิ้วกรัม procedure specifications (WPS).

VIII. Future developน.ent trends

Autoน.ated weldนิ้วกรัม: Robotic butt weldนิ้วกรัม systeน. improves the construction efficiency of large-diameter pipes with an accuracy of ±0.2มิลลิเมตร.

Arกรัมon-free technology: Flux-Cored Wire reduces the reliance on กรัมas protection durนิ้วg butt welding.

Intelliกรัมent detection: AI-driven real-tiน.e weld quality monitorนิ้วกรัม system (such as Olympus OmniScan X3).