Construction Method of Electrofusion Saddle Pipes: Standardized Procedures Ensure Branch Connection Quality

Electrofusion saddle pipes are crucial components for achieving uninterrupted branching on existing pipelines. Their construction method directly impacts connection reliability and project safety.This method, based on the principle of electrothermal fusion, integrates the saddle pipe with the main pipe and branch pipes through a series of standardized steps. It is suitable for thermoplastic pipes such as polyethylene (PE) and polypropylene (PP) and is widely used in municipal, gas, industrial, and water conservancy fields.

 

Adequate preparation is essential before construction. First, confirm the main pipe material, diameter, and operating parameters. Select a saddle pipe model matching the main pipe and check that its heating element resistance value meets specifications. Surface treatment of the branch locations on the main pipe's outer wall is necessary, removing dirt, grease, oxide layers, and sharp protrusions to ensure a tight fit with the saddle seat. If necessary, reinforce the main pipe to prevent displacement due to stress changes during heating and cooling. The branch pipe ends also need to be trimmed straight and deburred to facilitate easy insertion into the joint and maintain coaxiality.

 

Positioning and fixing are critical aspects of the construction process. Based on the design drawings, determine the branch's orientation and height. Wrap the saddle-shaped base around the main pipe and initially fix it, using clamps or straps for restraint to ensure uniform contact between the base and the main pipe's outer surface, with no gaps or wrinkles in the heating element area. Insert the branch pipe into the saddle-shaped pipe joint to the marked position, ensuring the insertion depth meets connection requirements, and temporarily fix it to prevent displacement.

 

The heating and melting stage is completed by an electrofusion welding machine. Reliably connect the welding machine's output electrode to the conductive contacts of the saddle-shaped pipe, and set matching heating voltage, current, and time parameters. After power is applied, the heating element heats up, causing the contact plastic between the inner side of the saddle-shaped base, the outer wall of the main pipe, and the branch pipe joint to melt simultaneously, forming a fusion zone. This process requires monitoring temperature and heating time to prevent overheating leading to material degradation or underheating causing poor bonding.

 

Cooling and setting are crucial steps that determine the connection strength. After heating, disconnect the power supply and allow the molten zone to gradually solidify under natural or controlled cooling conditions. During this period, do not move the pipe or apply external force to avoid cracking or stress concentration in the bonding layer. Cooling time depends on pipe diameter and wall thickness. The fixing device can only be removed and subsequent procedures carried out after the material has fully solidified.

 

After construction, a visual and quality inspection should be performed. Check that the joints are uniform and free of defects, with no melt overflow or burn marks, and that the branch pipe and main pipe are accurately aligned. If necessary, pressure tests or pressure holding observations should be conducted to verify that the sealing performance of the branch joints meets design requirements.

 

Throughout the construction process, ambient temperature, humidity, and cleanliness will affect the final quality. In cold weather, insulation measures are required; in humid environments, moisture should be prevented from entering the molten zone. Construction personnel must be professionally trained, strictly follow operating procedures, and retain construction records and parameter data for traceability and evaluation.

 

In summary, the construction method for electrofusion saddle pipes focuses on surface treatment, precise positioning, parametric heating, and controlled cooling. Through standardized processes and strict quality control, it ensures that branch connections have the same sealing performance and strength as the main pipe, providing reliable protection for the safe expansion of the pipeline system.