Anchor Flanges / AF-G
Guide Anchor Flange
Directed anchor flange providing controlled linear movement and guiding support.
Technical Specifications
Key Features
- Controlled linear movement
- Axial load support
- Radial restraint
- Sliding surfaces
- Lubrication channels
- Wear plates
Applications
- Thermal expansion lines
- Long pipe runs
- Heat exchanger connections
- Steam lines
- Chemical plants
- Refineries
Design Features
- Sliding bearing surfaces
- Wear pad plates
- Lubrication system
- Movement sensor mount
- Sealing gasket
Dimension Table
| Size | Outside Diameter (mm) | Thickness (mm) | Bolt Circle (mm) | No. of Bolts | Guide Length (mm) | Clearance (mm) |
|---|---|---|---|---|---|---|
| 4" | 235 | 20 | 152.5 | 8 | 200 | 5 |
| 6" | 285 | 23 | 190.5 | 8 | 250 | 5 |
| 8" | 350 | 26 | 241.5 | 8 | 300 | 6 |
| 12" | 490 | 33 | 355.5 | 12 | 400 | 6 |
| 16" | 605 | 39 | 457 | 16 | 500 | 8 |
| 24" | 760 | 49 | 641 | 20 | 600 | 8 |
Technical Notes
- 01Sliding surfaces must be lubricated regularly.
- 02Movement range must be limited.
- 03Wear plates require periodic inspection.
- 04Thermal expansion must be calculated.
What is an anchor flange?
An anchor flange is a heavy forged flange welded into a pipeline and encased in a concrete anchor (thrust) block. It is not a bolted joint: its job is to fix the pipe axially and transfer thrust loads from thermal expansion and internal pressure into the structure. Produced from 2" to 60" to ASME/AWWA practice or fully custom design.
Where and how anchor flanges are used
Anchor flanges are placed wherever the pipeline needs a fixed point: pump and compressor station boundaries, both banks of river and road crossings, steep slopes, aboveground-to-buried transitions and line terminations. The flange is butt-welded into the pipe on both sides and then embedded in a concrete block; expansion forces spread into the concrete through its large outside diameter. Unlike a standard flange it has no gasket face and no bolt holes — it is purely a load-transfer component. Each unit is custom-engineered from the pipe diameter, wall thickness, operating pressure and axial load calculation. Materials: forged carbon steel A105, A694 F42–F70 to match line pipe strength, A350 LF2 for low temperature. Delivered with NDT (UT/MT) and 3.1 certificates.
Frequently Asked Questions
What is the difference between an anchor flange and a standard flange?+
A standard flange is a bolted, demountable joint; an anchor flange has no gasket face or bolt holes — it is a load-transfer component that fixes the pipe into concrete.
What loads does an anchor flange carry?+
Axial thrust loads from thermal expansion/contraction and internal pressure; it takes them from the welded pipe and transfers them into the concrete anchor block.
Where are anchor flanges installed?+
At pump/compressor station boundaries, on both banks of river and road crossings, on steep slopes, at aboveground-to-buried transitions and at line terminations.
Which materials are anchor flanges made from?+
Forged carbon steel A105, A694 F42–F70 to match line-pipe strength, or A350 LF2 for low-temperature service; dimensions are engineered per project and verified with NDT + 3.1 certificates.
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