Lap Welding Connection

1.Basic Definition:

Lap welding is a connection method where the pipe ends are processed into a socket structure, allowing two pipe sections to partially overlap before welding. It is commonly used for thin-walled stainless steel pipes with a wall thickness of less than 2mm or small-diameter plastic-coated steel pipes.

2. Advantages and Features:

Convenient construction and simple beveling: No complex beveling preparation is required, assembly is easy, and it is suitable for rapid on-site construction.

Lower cost: Shallow weld depth, small heat-affected zone, minimal weld deformation, and no additional processing required.

Compatible with thin-walled pipes: Avoids the risk of burn-through in thin-walled pipes associated with butt welding, ensuring weld quality.

3. Applicable Fields: 

Thin-walled stainless steel pipes for building water supply; low-pressure, normal-temperature water supply and drainage pipelines; non-critical low-pressure chemical pipelines; cost-sensitive civil engineering pipelines.

4. Applicable Standards:

Technical Standard for Metal Piping Engineering of Building Water Supply* (CJJ/T 154-2020);

Steel-Plastic Composite Pipes and Fittings for Fluid Transportation* (GB/T 28897-2021);

Construction Specification for Welding Engineering of On-Site Equipment and Industrial Piping* (GB 50236-2011).

5. Connection Characteristics:

The connection type is rigid, with no displacement compensation capability; the weld strength is lower than that of butt welds, making it unsuitable for high-pressure and impact conditions;

After welding, anti-corrosion treatment is required for the weld area to avoid corrosion weak points.