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Non-Circular GRP Pipes

Non-circular GRP (Glass Reinforced Polyester) pipes are custom-profile fiberglass culverts and conduits designed for applications where traditional round pipes won’t fit. Available in shapes like egg, oval, arch, and custom profiles, these GRP sections are produced by high-strength filament winding or hand layup and are ideal for culvert rehabilitation, stormwater drains, culverts under roadways/railways, tunnels, and even architectural channels. Compared to rigid liners, non-circular GRP pipes add structural integrity to existing channels, bearing loads with long-term durability. With design lives of 100+ years, these pipes combine light weight, corrosion resistance, and high hydraulic capacity in a tailored geometry.

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Key Features

  • Custom Shapes: Profiles include egg, elliptical, arch, jaw-shaped, inverted-egg and other complex cross-sections to suit project needs.
  • High Strength & Stiffness: Filament-wound GRP offers high bending stiffness (SN2500–SN10000) and tensile strength, enabling pipes to handle earth loads and flow pressures.
  • Corrosion & Abrasion Resistance: Inert to sewage, stormwater, chemicals and abrasion from slurry flows.
  • Smooth Interior: GRP’s glassy surface maximizes hydraulic flow (often increasing capacity compared to old pipelines).
  • Lightweight Construction: Easy to transport and install in confined trenches or jacking operations.
  • Flexible Jointing: Accepts rubber-ring joints (RRJ) or laminated butt joints for quick assembly.
  • Longevity: Engineered for a 100+ year design life even under buried or submerged conditions.

Benefits

  • Rehabilitation of Aged Infrastructure: Ideal for relining existing sewers and culverts with reduced excavation. The egg/arch shapes restore structural capacity to century-old conduits.
  • Maximized Hydraulic Performance: Custom cross-sections often provide greater flow area than circular pipes in limited space.
  • Reduced Installation Time and Cost: Light pipes and simple joint systems speed construction; no heavy machinery needed for lifting.
  • Low Maintenance: No corrosion, so no need for coatings or cathodic protection; smooth interior resists fouling and scaling.
  • Design Flexibility: Can be engineered to fit under railways, roads or buildings where height or width is constrained (e.g. low-profile arch shapes).

Applications

  • Culverts & Stormwater Drains: Road and railway culverts (egg/arch profiles) handling highway runoff and drainage.
  • Sewer & Wastewater Conduits: Non-circular profiles for gravity sewers in urban or confined environments.
  • Trenchless Construction: Jacking/micro-tunneling installations for drainage or cable ducts where space is limited.
  • Architectural & Landscape: Custom GRP channels or benches in parks, resorts or urban plazas (GRP’s corrosion resistance and aesthetics).
  • Industrial Facilities: Flow channels, effluent return lines or process bins requiring special shapes.

Technical Specifications (Typical)

  • Material: Filament-wound glass-fiber reinforced polyester (vinylester or epoxy as needed).
  • Profiles: Egg, elongated egg, arch, rectangular (with rounded corners), inverted-Jaw, and custom shapes.
  • Stiffness Class: Typically SN2500 to SN10000 (N/m²) to resist deflection.
  • Joint System: Rubber ring joints (RRJ) or butt joints with lamination tape (no corrodible metal parts).
  • Design Life: ≥100 years per ISO 9001 quality processes.
  • Standard Lengths: 2–3 m pipes (up to 6 m lengths available), with matching shaped fittings and manholes.

Unique Selling Points (USPs)

  • Fully Customizable Shapes: We deliver virtually any profile to match existing conduits or design specifications.
  • Structural Rehabilitation Capability: The GRP lining becomes a permanent structural member, eliminating the need for concrete sleeves or linings.
  • High Hydraulic Efficiency: Glass-smooth interior increases flow versus rough concrete or deformed pipes.
  • Joint Integrity: Leak-free assembly with flexible gaskets ensures system watertightness and pipeline continuity.
  • Expert Engineering Support: Our team provides hydraulic and structural analysis to optimize shapes and wall thickness for each project.