Clamp Insert Options for Large-Size Butt Fusion Machines: Steel, Aluminum and Anti-Slip Pads
For large-size butt fusion machines, clamp inserts are used to match different pipe diameters and help keep the pipe securely clamped and properly aligned throughout the fusion process.
Welping large-size butt fusion machines can be configured with two types of clamp inserts:
· CoreClamp Steel
· CoreClamp Aluminum
For 800 / 1000 / 1200 models, optional anti-slip pads are also available to improve pipe holding stability and provide a small range of adjustment for pipes with slight outside-diameter variation.
CoreClamp Steel
CoreClamp Steel inserts are made from precision-cut steel and welded into a strong, rigid structure for large-diameter butt fusion applications.
The inner surface features anti-slip serrations, which help increase friction between the insert and the pipe. This reduces relative movement during alignment, facing, heating and fusion.
Steel inserts use a two-piece design. Each complete insert size consists of an upper and a lower half, which are installed inside the corresponding machine clamps.
Main Features
· Steel construction with high structural rigidity
· Anti-slip serrations on the inner surface
· 2 pieces per complete insert size
· Fewer pieces to install
· Selected non-standard sizes can be customized for specific projects
Available Sizes
· Steel construction with high structural rigidity
· Anti-slip serrations on the inner surface
· 2 pieces per complete insert size
· Fewer pieces to install
· Selected non-standard sizes can be customized for specific projects
CoreClamp Aluminum
CoreClamp Aluminum inserts are made from high-strength aluminum alloy. Compared with steel inserts, the lower weight of each individual section makes handling easier, especially on large machines where inserts may need to be moved and replaced manually.
The aluminum version uses a four-piece split design.
For the same machine size:
· Steel insert: 2 pieces
· Aluminum insert: 4 pieces
This means that a complete aluminum insert set requires twice as many pieces to be installed as the steel version.
However, each individual aluminum section is smaller and lighter, which can make manual handling and piece-by-piece installation easier on large-diameter machines.
The aluminum insert also features a widened pipe-contact surface to provide stable support and help maintain pipe alignment.
Main Features
· High-strength aluminum alloy construction
· 4 pieces per complete insert size
· Lower weight per individual piece
· Easier manual handling and piece-by-piece installation
· Widened pipe-contact surface
· Convenient for applications where insert sizes are changed frequently
Standard Sizes
630 / 710 / 800 / 900 / 1100 / 1200 mm
Specific availability depends on the machine model.
Key Differences Between Steel and Aluminum Inserts
Both types are designed for pipe size reduction, clamping and alignment. The main differences are in material, structure and handling.
| Item | CoreClamp Steel | CoreClamp Aluminum |
| Material | Steel | High-strength aluminum alloy |
| Pieces per complete size | 2 pieces | 4 pieces |
| Weight per piece | Relatively heavier | Relatively lighter |
Number of pieces to install | Fewer | Twice that of steel inserts |
Pipe-contact design | Anti-slip serrations | Widened contact surface |
Handling | Simple two-piece structure | Lighter individual sections for manual handling |
Non-standard sizes | Customization available | Depends on model and size |
Standard size range | Available for larger machine sizes | Mainly 630–1200 mm |
Where fewer installation pieces and a simple two-piece structure are preferred, steel inserts may be more suitable for the operating routine.
Where inserts are frequently handled manually or changed between different pipe sizes, the lighter individual sections of aluminum inserts can make handling more convenient.
Optional Anti-Slip Pads for 800 / 1000 / 1200 Models
For 800, 1000 and 1200 models, optional anti-slip pads can be installed at the contact area between the machine clamps and the pipe.
They mainly provide two functions:
· Improve pipe holding stability
· Provide limited adjustment for slight pipe diameter variation
1. Larger Contact Area, Less Pipe Slippage
Installing anti-slip pads increases the contact area between the upper and lower machine clamps and the pipe. This also increases friction at the clamping surface.
When the machine moves the pipe forward or backward, the larger contact area helps reduce relative movement between the pipe and the clamps. This helps keep the pipe more stable during facing, heating and fusion.
This can be particularly useful in low-temperature working conditions.
At lower temperatures, PE pipe becomes stiffer and may not conform to the clamping surface as easily. The added contact area and friction provided by the anti-slip pads can help improve holding stability, especially when moving large and heavy pipes.
This option can therefore be useful for:
· Cold-region projects
· Winter construction
· Large-diameter or heavy pipes
· Applications where pipe movement resistance is relatively high
2. Small Adjustment for Slight Diameter Variation
The position of the anti-slip pads can be adjusted within a limited range.
If the actual pipe OD differs slightly from the nominal size, the pad position can be fine-tuned to improve contact with the pipe and provide a more stable clamping condition.
This function is intended for small dimensional variations, for example:
· Slightly non-standard pipe sizes
· Special project pipe
· Pipes with minor OD deviation
If the difference from the standard pipe size is significant, the correct insert size or a customized insert should still be used.
Confirming the Right Clamp Configuration
Before confirming the machine configuration, it is helpful to provide:
· Machine model
· Pipe outside diameter
· Standard or non-standard pipe size
· Whether insert sizes will be changed frequently
· Whether inserts will mainly be handled manually
· Expected working temperature or site conditions
· Whether anti-slip pads are required for 800 / 1000 / 1200 models
With this information, the clamp insert and pipe-holding configuration can be confirmed before the machine is delivered.