Addressing Vacuum Loss in PE Three-Layer Co-Extrusion Pipe Production Lines

When operating a PE three-layer co-extrusion pipe production line, encountering a sudden loss of vacuum can be a disruptive issue. However, with proper diagnosis and targeted corrective measures, this problem can be efficiently resolved.

Ningbo Fangli Technology Co., Ltd., with over 30 years of expertise in plastic pipe extrusion machinery and advanced environmental and new materials equipment, has built a reputation for engineering excellence and user-centric innovation. Through continuous technological refinement, independent R&D, and the integration of global best practices, Fangli has developed a comprehensive range of extrusion solutions, including PVC, PP-R, and PE water supply/gas pipe production lines—recognized by the Chinese Ministry of Construction as recommended alternatives to imported equipment. Our commitment to quality has also earned us the title of “First-class Brand in Zhejiang Province.”

Our PE three-layer co-extrusion lines utilize vacuum sizing technology to ensure precision and product quality. Nevertheless, if the system is not finely tuned or if processing conditions are suboptimal, issues such as internal jitter rings or vacuum failure may occasionally arise. These are typically not critical failures and can be resolved through systematic inspection and adjustment.

If internal jitter rings are observed in the pipe:

· Adjust the water outlet of the sizing sleeve to ensure uniform flow distribution.

· Fine-tune the vacuum levels in the sizing chamber so that the rear chamber maintains a slightly higher vacuum than the front chamber.

· Verify that the vacuum sealing gasket is not overtightened.

· Check the tractor unit for any signs of vibration or instability.

· Ensure that the extruder discharge is consistent and even.

Once these parameters are corrected, the jitter phenomenon will generally resolve automatically.

If there is a complete loss of vacuum:

· Inspect the vacuum pump water inlet for blockages; if clogged, clear it using a fine needle.

· Confirm that the vacuum pump is operating normally.

· Examine the vacuum piping system for leaks.

· Check the small borehole in the center of the core mold compression screw; if obstructed, clear it gently with a thin iron wire.

These are routine maintenance issues that can be handled promptly with proper care, ensuring minimal production disruption.

For further technical support or equipment inquiries, Ningbo Fangli Technology Co., Ltd. invites you to reach out to our team. We are committed to providing professional guidance, whether you require process troubleshooting or procurement advice