Plain End Pipe

This instruction has been prepared for the correct and safe installation of Plain End Pipe used to complete the distance between two fixed points in pipeline systems, or to be installed between two pipe coupling/adaptor units during repair applications.

1. Pre-Installation Checklist

• Product Verification:
  Check the label information (DN size and tolerance range) and ensure compatibility with the pipe outer diameters.
• Dimensional Verification:
  Confirm that the length of the spacer pipe matches the required gap or removed section in the pipeline.
• Coating Inspection:
  Inspect internal and external coatings (Epoxy, Galvanized, etc.) for any transport-related damage.
  Repair damaged areas before installation.

2. Installation Procedure

2.1 Cleaning and Preparation

• Clean the ends of both the pipeline and the spacer pipe.
• Ensure sealing surfaces are free from rust, dirt, old gasket residues, and debris.

2.2 Chamfering (If Required)

• Apply an external chamfer of approximately 30° to pipe ends if necessary.
• This prevents damage to sealing gaskets during insertion.

2.3 Alignment (Centering)

• Position the spacer pipe within the pipeline.
• Ensure proper axial alignment between the spacer pipe and existing pipeline.
• Leave a 5–10 mm gap between pipe ends to allow for thermal expansion and settlement.

2.4 Adapter / Coupling Placement

• Apply a suitable lubricant to the pipe ends and sealing areas.
• Slide the coupling/adaptor units over both ends of the spacer pipe and align them to the previously marked positions.
• Ensure equal insertion depth on both sides.

2.5 Tightening (Critical Step)

• Insert bolts and hand-tighten nuts until snug.
• Tighten bolts in a crosswise (diagonal) sequence (12–6 o’clock, 3–9 o’clock).
• Tighten gradually and evenly to ensure uniform gasket compression and sealing.

2.6 Support and Fixing

• For longer spacer pipes, use pipe supports, hangers, or base supports to prevent excessive load on couplings/adaptors.
• Ensure that the spacer pipe weight is not transferred to connection points.

3. Final Inspection & Testing

• Visual Inspection:
  Check that there are no gaps between the spacer pipe and coupling/adaptor units, and that alignment is uniform around the circumference.
• Pressure Test:
  Before commissioning, perform a low-pressure leak test.
  If leakage is detected, recheck and retighten bolts accordingly.