Rigid Polyvinyl Chloride (PVC-U) Porous Pipe—Honeycomb Pipe for Underground Communication Conduits

Honeycomb conduits are typically installed underground in municipal, highway, airport, and port projects. When used above bridges or on pipe racks in non-underground installations, protective measures must be implemented to prevent aging and mechanical damage. They exhibit excellent properties such as acid resistance, anti-aging performance, flame retardancy, and superior insulation. Their operating temperature range is from –20°C to 40°C, making them suitable for both cold and hot climates, with a service life of over 50 years. The inner and outer conduits are integrated into a single unit, reducing the need for additional sheathing and lowering material costs. They also demonstrate outstanding impact resistance, compressive strength, and aging resistance, with overall excellent physical and mechanical properties. Furthermore, the inner conduits are supported by multiple brackets to form a conduit bundle, which prevents slippage and reduces the pressure exerted on the inner conduits by the optical cable.

Purpose:

Honeycomb conduits are generally installed underground in municipal, highway, airport, and port projects. When such conduits are installed above bridges or on pipe racks in non-underground applications, protective measures must be implemented to prevent aging and mechanical damage.
It features acid resistance, aging resistance, flame retardancy, and excellent insulation performance. Its operating temperature range is –20°C to 40°C, making it suitable for both cold and hot climates, with a service life of over 50 years. The inner conduit and outer sheath are integrated into a single unit, reducing the need for separate protective sheathing and lowering material costs. It exhibits outstanding impact resistance, compressive strength, and aging resistance, with superior overall physical and mechanical properties. Moreover, adjacent inner conduits are supported by multiple brackets to form a bundled conduit assembly, which prevents slippage and reduces the pressure exerted on each conduit by the optical cable.

Selection of Installation Parameters and Position for Honeycomb Panels

1. Burial depth of the honeycomb pipe (from the top of the pipe to the road surface): shall be no less than 0.5 m under sidewalks and no less than 0.7 m under roadways, and in relation to tram tracks
The clearance between the pipeline and the railway track (measured from the top of the pipeline to the bottom of the track) shall not be less than 1.00 m; when crossing a railway, this clearance shall not be less than 1.5 m. When multiple layers of plastic pipelines are laid, each layer should be compacted separately, and the burial depth should be appropriately increased. If these requirements cannot be met, protective measures such as concrete encasement or steel pipe protection shall be adopted.
2. Selection of honeycomb duct location:
1) Pipelines should preferably be laid beneath the sidewalk; when laying them beneath the sidewalk is not feasible, they may be laid beneath the bicycle lane, but should not be laid beneath the motor vehicle lane.
2) Pipelines on high-grade highways should be located at appropriate sites beneath the median strip, under the road shoulder, or within the protective fence.
3) The pipeline should preferably be located on the side with more users;
4) The pipeline centerline shall be parallel to the road centerline or the building red line; 5) Pipelines should not be constructed in close proximity to other utility lines that are buried at greater depths.
3. Combination of honeycomb tubes:
1) The pipe bundle shall be arranged in a rectangular pattern, with an even number of pipe holes in the transverse direction.
2) Pipes with larger pipe-hole diameters shall be placed at the bottom and outer side of the pipe bundle, while pipes with smaller pipe-hole diameters shall be placed at the top and inner side of the pipe bundle.
3) For the same pipe group assembly, it is recommended to use a single type of perforated pipe.
4) The voids between multi-layer plastic pipes shall be tightly packed in layers.

Transportation, Handling, and Storage of Honeycomb Panels

During loading, unloading, and transportation, the product must not be subjected to severe impact, dropping, or excessive pressure.
Pipes shall be stored on a level, well-prepared site, stacked neatly, with a maximum stack height of 2 meters, at least 1 meter away from heat sources, and protected from direct sunlight.

Technical Requirements for Honeycomb Pipe Joints

1) The inner wall profile of the pipe fitting shall be exactly identical to the outer wall profile of the perforated pipe, and the gap between the inner wall of the pipe fitting and the outer wall of the perforated pipe after socket connection shall not exceed 0.5 mm;
2) The length of the pipe fitting shall not be less than 200 mm;
3) The inner cross-section at the longitudinal center of the pipe fitting shall be provided with an annular retaining shoulder on the inner wall. After the porous pipe is inserted into the fitting, this retaining shoulder shall be in contact with the outer end face of the porous pipe, with a contact width of not less than 1.6 mm.

• Honeycomb
• pipeline
• pipe fitting
• porous
• laying