Pipe Join (インチ)t ソルutions Butt Weld Socket Weld

I. Technical prin (インチ)ciple and structural design

1. Butt weldin (インチ)g

Connection method: Align the end faces of the two pipes directly and fuse them by fillin (インチ)g solder to form a continuous weld.

Structural features:

• The weld is consistent with the pipe wall thickness, there is no protrudin (インチ)g structure, and the flow resistance is small.
• The groove (V-type, U-type or J-type) needs to be processed to ensure the penetration rate.
• Standard specification: ASME B16.25 specifies the dimensional tolerance and surface treatment requirements of the butt weldin (インチ)g groove.

2. Socket weldin (インチ)g

Connection method: Insert the pipe in (インチ)to 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.

Structural features:

• There is a 1.6mm expansion gap between the pipe and the pipe fittin (インチ)g (ASME B31.3 requirement).
• The weld is located between the outer wall of the pipe and the socket of the pipe fittin (インチ)g to form a mechanical lock.

Standard specification: ASME B16.11 defin (インチ)es the pressure grade and size series of socket welding pipe fittings.

II. Comparison of process requirements and operation procedures

1. Butt weldin (インチ)g construction process

溝 processin (インチ)g:

• Use a groove machin (インチ)e to cut a V-shaped groove (angle 60°±5°, blunt edge 1.6mm).
• Clean the oil and rust within (インチ) 20mm of the inner and outer walls of the groove.

Assembly and spot weldin (インチ)g:

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

Multi-layer weldin (インチ)g:

• The base weldin (インチ)g adopts TIG process (argon purity ≥99.99%), and the filling welding and cover welding can be selected by SMAW or GMAW.
• The in (インチ)terlayer temperature is controlled at 150~250℃ (carbon steel) or ≤150℃ (stainless steel).

Post-weld treatment:

• Perform 100% radiographic testin (インチ)g (RT) or ultrasonic testing (UT) to eliminate unfused or pore defects.

2. Socket weldin (インチ)g construction process

Pipelin (インチ)e pretreatment:

• Cut the pipe to a length tolerance of ±0.8mm to ensure that the in (インチ)sertion depth meets the requirements.

Assembly and positionin (インチ)g:

• Insert the pipe in (インチ)to the socket of the pipe fitting, leaving a 1.6mm axial gap (to prevent thermal stress cracking).

塗りつぶしet weld weldin (インチ)g:

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

Inspection and acceptance:

• Visual in (インチ)spection (VT) to check the continuity of the weld, and perform penetration testing (PT) if necessary.

III. Comparison of core performance and economic efficiency

IV. Analysis of in (インチ)dustry application scenarios

1. Typical applications of butt weldin (インチ)g

Long-distance oil and gas pipelin (インチ)es:

Requirements: withstand high pressure (≥10MPa), resist hyd (ヤード)rogen sulfIDe stress corrosion.

ソルution: X65 steel grade pipelin (インチ)e + U-shaped groove, multi-pass welding with post-weld heat treatment (PWHT).

Nuclear power main (インチ) steam pipeline:

Requirement: zero leakage, thermal fatigue resistance.

ソルution: Austenitic stain (インチ)less steel + automatic orbital welding, 100% radiographic flaw detection.

2. Typical applications of socket weldin (インチ)g

Chemical in (インチ)strument pressure pipe:

Requirement: small pipe diameter (DN15~25), easy to disassemble and calibrate.

ソルution: 316L stain (インチ)less steel socket welding valve + gas shielded welding of fillet weld.

Ship ballast water system:

Requirement: fast in (インチ)stallation, vibration resistance.

ソルution: galvanized steel pipe with socket weldin (インチ)g flange, epoxy anti-corrosion coating after welding.

V. Key factors for selection decision

System pressure and temperature:

• High pressure and high temperature (P≥5MPa, T≥200℃) give priority to butt weldin (インチ)g.
• 中 and low pressure and normal temperature systems can consIDer socket weldin (インチ)g to reduce costs.

Pipe diameter and space restrictions:

• When the pipe diameter is below DN80 and the in (インチ)stallation space is narrow, socket welding is easier to operate.
• For large pipe diameters (≥DN150), butt weldin (インチ)g must be used to ensure structural strength.

Main (インチ)tenance and inspection requirements:

• For pipelin (インチ)es that need to be frequently disassembled and repaired (such as sampling systems), socket welding is more economical.
• For pipelin (インチ)es involving highly toxic or radioactive media, the full penetration structure of butt welding is safer.

VI. Common problems and solutions

1. Typical defects of butt weldin (インチ)g

Incomplete penetration: adjust the groove angle or in (インチ)crease the welding current to ensure root fusion.

Heat-affected zone cracks: control the in (インチ)terlayer temperature, slow cooling after welding or perform stress relief heat treatment.

2. Typical defects of socket weldin (インチ)g

Insufficient gap: check with a feeler gauge before in (インチ)stallation to ensure a 1.6mm expansion gap.

The weld is not filled: in (インチ)crease the number of welds or use a larger diameter electrode.

VII. Industry standards and compliance requirements

ASME B31.3: specifies the process assessment and in (インチ)spection standards for butt welding and socket welding.

API 570: requires wall thickness in (インチ)spection of butt-welded pipes every 5 years, and socket welding needs to focus on checking the corrosion of fillet welds.

ISO 15614-1: Certification requirements for weldin (インチ)g procedure specifications (WPS).

VIII. Future development trends

自動mated weldin (インチ)g: Robotic butt weldin (インチ)g system improves the construction efficiency of large-diameter pipes with an accuracy of ±0.2mm.

Argon-free technology: Flux-Cored Wire reduces the reliance on gas protection durin (インチ)g butt welding.

Intelligent detection: AI-driven real-time weld quality monitorin (インチ)g system (such as Olympus OmniScan X3).