Ductile Iron Flange Adaptor

This instruction has been prepared for the safe and leak-tight installation of wide-tolerance ductile iron flange adaptors used to connect different types of pipes (Ductile iron, Cast iron, Steel, PVC, PE, GRP, AC, etc.) to flanged equipment.

1. Pre-Installation Preparation

• Product Check:
  Verify the label information on the adaptor (DN size and tolerance range) and ensure it is suitable for the outer diameters of the pipes to be connected.
• Flange Compatibility:
  Check that the adaptor flange matches the mating flange (PN10, PN16, PN25, etc.) in terms of bolt hole number and pitch circle diameter (PCD).
• Pipe Cutting:
  Cut the pipes perpendicular (approx. 90°) to the pipe axis. Uneven cuts may prevent proper seating of the sealing gasket.
• Surface Cleaning:
  Clean rust, dirt, scale, and old coatings from the pipe ends using a wire brush.
  The surface in contact with the sealing gasket must be smooth and clean.
• Chamfering (If Required):
  Apply an external chamfer of approximately 30° to the pipe end if necessary.
  This prevents damage to the gasket during insertion.

2. Positioning and Marking

• Insertion Depth Marking:
  Measure the adaptor body length and mark a reference line on the pipe equal to half of the adaptor length.
• Pipe Alignment:
  Flange adaptors typically allow up to ±3° angular deviation; however, proper alignment is recommended for optimal performance.

3. Installation Steps

• Lubrication:
  Apply a silicone-based lubricant suitable for potable water to the gasket and pipe end.
  (Do not use oil-based lubricants as they may damage the gasket.)
• Placement:
  Slide the adaptor loosely onto the pipe.
• Flange Connection:
  Align the adaptor flange with the mating flange (valve or equipment).
  Insert a standard flange gasket between the flanges.

4. Tightening Procedure (Critical Step)

• Flange Bolt Tightening:
  First, tighten the flange bolts in a star (crosswise) pattern to fix the adaptor in position.
• Adaptor Bolt Tightening:
  Tighten the adaptor bolts diagonally (e.g., 12–6 o’clock, 3–9 o’clock).
  This ensures even load distribution on the gasket.
• Gradual Tightening:
  First hand-tighten all bolts, then tighten gradually in multiple passes using a wrench.

5. Final Check and Testing

• Visual Inspection:
  Ensure that the gap between the pressure flanges and the adaptor body is uniform around the entire circumference.
• Pressure Test:
  Perform a low-pressure leak test before commissioning the pipeline.
  If leakage is detected, recheck and retighten the bolts.

SAFETY NOTES

• Wear protective gloves and safety footwear during installation.
• For large-diameter adaptors, use pipe supports or blocking elements to prevent excessive load on the adaptor.
• Ensure that the protective coating of bolts (galvanized, Dacromet, etc.) is not damaged to maintain corrosion resistance.