Lap Joint Flanges — Easy Alignment | Cost-Effective | ASME / DIN / EN Standards

Lap Joint Flanges are designed to be used with a stub end, allowing the flange to rotate freely around the pipe for easy bolt hole alignment. This makes them particularly suitable for piping systems where frequent dismantling, alignment adjustments, or space constraints are present.

These flanges are ideal for low-pressure, non-critical applications, offering a cost-effective alternative to welding neck or socket welding flanges. Since the flange itself is not welded to the pipe, it can be reused easily, reducing maintenance costs in large piping systems.

Standards & Pressure Ratings

Lap joint flanges are manufactured according to international standards to ensure dimensional compatibility and reliable performance:

• ASME B16.5 — Class 150, 300, 600 and above upon request
• DIN / EN 1092-1 — PN6, PN10, PN16, PN25, PN40
• Available in Raised Face (RF) or Flat Face (FF) configurations depending on application

Key Features

• Easy Alignment — The flange can rotate around the pipe, simplifying bolt hole alignment during installation.
• Cost-Effective — Ideal for systems where frequent dismantling or maintenance occurs.
• Stub End Integration — The pipe is welded to a stub end while the flange remains loose, allowing flexibility and reusability.
• Reduced Maintenance Costs — Flanges can be reused across multiple piping configurations.
• Material Versatility — Available in carbon steel, stainless steel, and special alloys to suit various environments.

Typical Dimensions

• Size Range: ½” to 24” (DN15–DN600) and above
• Pressure Ratings: ASME Class 150 – 300 / DIN PN6–PN40
• Facing Options: RF / FF
• Drilling: Standard bolt hole patterns per ASME / DIN standards

Applications

• Low-pressure piping systems
• Systems requiring frequent dismantling and reassembly
• Large-diameter pipelines where bolt alignment is challenging
• Water treatment and distribution networks
• Chemical, oil & gas, and general industrial applications