HLY-GEN-03: Trenchless Jacking Pipe Manufacturing Tolerances & Steel Collar Inspection Protocol

1. Jacking Pipe Manufacturing Tolerance Limits

End Face Squareness: Perpendicularity deviation must be $\le$ 0.8 mm (exceeding 1.0 mm causes catastrophic edge spalling under high jacking thrust).

Overall Pipe Length: Tolerance $\pm$2.0 mm.

Outer Diameter Roundness: Ovality tolerance $\le \pm$2.0 mm.

Axial Straightness: Straightness runout $\le$ 2.0 mm over entire length.

2. F-Type Steel Collar Fabrication & Corrosion Protection

Formed from 6–10 mm Q235B steel plate with submerged-arc full penetration seam welds.

Collar overhang dimension tolerance: $\pm$2.0 mm.

Grit-blast exterior to Sa 2.5 cleanliness; apply $\ge$ 300 $\mu$m high-build coal-tar epoxy coating.

3. Wooden Cushion Packing & Grout Port Quality Control

Ship each pipe with 12–18 mm marine-grade plywood stress-equalizing cushion rings.

Check all three 120° spaced G1" threaded bentonite slurry injection sockets for 0.3 MPa air tightness.

1. Jacking Pipe Manufacturing Tolerance Limits

End Face Squareness: Perpendicularity deviation must be $\le$ 0.8 mm (exceeding 1.0 mm causes catastrophic edge spalling under high jacking thrust).

Overall Pipe Length: Tolerance $\pm$2.0 mm.

Outer Diameter Roundness: Ovality tolerance $\le \pm$2.0 mm.

Axial Straightness: Straightness runout $\le$ 2.0 mm over entire length.

2. F-Type Steel Collar Fabrication & Corrosion Protection

Formed from 6–10 mm Q235B steel plate with submerged-arc full penetration seam welds.

Collar overhang dimension tolerance: $\pm$2.0 mm.

Grit-blast exterior to Sa 2.5 cleanliness; apply $\ge$ 300 $\mu$m high-build coal-tar epoxy coating.

3. Wooden Cushion Packing & Grout Port Quality Control

Ship each pipe with 12–18 mm marine-grade plywood stress-equalizing cushion rings.

Check all three 120° spaced G1" threaded bentonite slurry injection sockets for 0.3 MPa air tightness.

HLY-GEN-03: Trenchless Jacking Pipe Manufacturing Tolerances & Steel Collar Inspection Protocol

1. Jacking Pipe Manufacturing Tolerance Limits

2. F-Type Steel Collar Fabrication & Corrosion Protection

3. Wooden Cushion Packing & Grout Port Quality Control

تنزيل المرفق

HLY-GEN-03: Trenchless Jacking Pipe Manufacturing Tolerances & Steel Collar Inspection Protocol

1. Jacking Pipe Manufacturing Tolerance Limits

2. F-Type Steel Collar Fabrication & Corrosion Protection

3. Wooden Cushion Packing & Grout Port Quality Control

تنزيل المرفق