Product Description

Manufactured by filament winding continuous glass fiber rovings impregnated with thermosetting resin (polyester, vinyl ester, or epoxy) onto the external surface of steel pipe, followed by curing. Features excellent corrosion resistance, high mechanical strength, good electrical insulation, and lightweight compared to solid steel. Base pipe materials: carbon steel (API 5L Gr B, X42–X80, ASTM A106 Gr B, Q235B, Q355B) or stainless steel. Pipe outer diameter: 50mm – 1600mm. Wall thickness: 2.5–40mm. Standard length: 6m, 12m (custom). FRP thickness: 2mm – 10mm (depending on design pressure and corrosion allowance). Resin types: orthophthalic (general), isophthalic (superior corrosion), vinyl ester (chemical resistant). Fiberglass content: 60–75% by weight. Service temperature: -40°C to +180°C (resin dependent). Tensile strength of FRP layer: ≥ 200 MPa. Flexural strength: ≥ 250 MPa. Holiday test: 5–15kV spark test (if conductive liner used). Excellent resistance to acids, alkalis, salts, and most organic solvents. Provides cathodic protection shielding. Meets ASTM D2996, ISO 14692, or SY/T 0603 standards. Custom FRP thickness, resin type, and color available.

Parameter

Product Name	FRP Wrapped Steel Pipe (Glass Fiber Reinforced Plastic Coated Steel Pipe)
Base Pipe Materials	Carbon steel: API 5L Gr B, X42, X46, X52, X56, X60, X65, X70, X80; ASTM A106 Gr B; Q235B, Q355B; stainless steel (304/316L) optional
Base Pipe Type	Seamless, ERW, LSAW, SSAW
Pipe Outer Diameter	50 mm – 1600 mm (2" – 63")
Base Pipe Wall Thickness	2.5 mm – 40 mm (depending on diameter and grade)
Standard Length	6 m, 12 m (custom up to 18 m)
FRP Layer Thickness	2 mm – 10 mm (depending on design pressure and corrosion allowance)
Fiber Type	Continuous glass fiber rovings
Resin Type	Orthophthalic polyester (general purpose), isophthalic polyester (superior corrosion), vinyl ester (chemical/acid resistant)
Fiberglass Content (by weight)	60% – 75%
Manufacturing Process	Filament winding (helical and hoop layers)
Curing Method	Ambient or heat-cured
Service Temperature	Orthophthalic: -20°C to +80°C; Isophthalic: -40°C to +100°C; Vinyl ester: -40°C to +180°C
Tensile Strength (FRP layer – hoop)	≥ 300 MPa (depending on winding angle and fiber content)
Flexural Strength (FRP)	≥ 250 MPa
Tensile Modulus (FRP)	15 – 25 GPa
Elongation at Break (FRP)	1.5% – 2.5%
Hardness (Barcol)	≥ 40 (for cured resin)
Holiday Test	5 – 15 kV spark test (required if conductive carbon veil used)
Chemical Resistance	Excellent resistance to acids (dilute), alkalis, salts, hydrocarbons, and many organic solvents
Cathodic Protection Shielding	Yes (FRP is electrically non-conductive; use caution if CP is required)
Surface Preparation (Steel)	Blast cleaning to Sa 2.5, anchor profile 40 – 100 µm; primer applied if required
Standards Compliance	ASTM D2996, ISO 14692, SY/T 0603, or customer specification
Custom Options	FRP thickness, resin type (vinyl ester, epoxy), color (gel coat), anti-UV top coat, integrated fittings

Application description

Widely used in oil and gas gathering lines, water injection pipelines, chemical process piping, and seawater cooling systems. Also suitable for corrosive environments such as acid or alkaline transport, desalination plants, and underground or subsea pipelines where external corrosion protection and mechanical strength are required. The FRP layer provides excellent resistance to chemicals and soil stresses.

Production description

Steel pipe is surface cleaned (blast to Sa 2.5) and optionally primed. Continuous glass fibers impregnated with resin (polyester, vinyl ester, or epoxy) are helically wound onto the rotating pipe at controlled angles and tension. The pipe is cured (ambient or heat), then inspected for thickness, hardness, and holiday-free surface. Ends may be trimmed for fit-up.

Shipping Packaging

For export, FRP wrapped pipes are fitted with end caps, bundled with wooden separators and steel straps, packed on ISPM-15 pallets or steel skids, and protected with edge protectors. The FRP surface may be wrapped with foam or bubble wrap. Labels include steel grade, FRP thickness, dimensions, and heat number for safe sea freight.

Why Choose Us?

1.Factory Strength: Direct manufacturer with filament winding lines, computer-controlled winding angles, and in-house resin mixing and curing ovens, producing FRP wrapped steel pipes from 50mm to 1600mm OD to ASTM D2996, ISO 14692, and SY/T 0603 standards.

2.Quality Assurance: Strict control of fiber/resin ratio (60-75% glass content), hoop and helical winding tension, layer adhesion, and Barcol hardness (≥40); 100% visual and holiday spark inspection; mechanical testing (tensile, flexural) available.

3.Certifications & Reports: Mill test certificates for base pipe and FRP raw materials with each shipment; third-party inspections (SGS, BV, DNV) and NDT reports (UT for steel pipe, spark test for FRP) available upon request.

4.Customization & Service: Wide base pipe grades (API 5L Gr B–X80, ASTM A106, Q235B/Q355B), diameters 50–1600mm, FRP thickness 2–10mm, resin types (ortho/isophthalic polyester, vinyl ester, epoxy), custom colors (gel coat), anti-UV or anti-static top coats, and fast lead times.

5.Export Packaging: Plastic/wooden end caps + foam or bubble wrap + wooden separators + steel strapping + ISPM-15 pallets/steel skids + edge protectors + clear labeling for safe sea freight and FRP surface protection.

FAQ

1. How to store FRP wrapped steel pipes to avoid surface damage and UV degradation?

Store on level, padded wooden sleepers, keep pipes elevated and bundles secured with soft slings. Avoid dragging or rolling pipes over sharp edges. For outdoor storage longer than 3 months, use light-blocking tarpaulin or apply UV-resistant gel coat. Minor surface scratches can be repaired with chopped strand mat and resin. Deep damage exposing steel must be professionally rebuilt.

2. Is the FRP layer fully bonded to the steel pipe? What happens if the FRP is damaged?

Yes, the FRP layer is directly wound onto blast-cleaned steel (or with a primer) to form a strong mechanical and chemical bond. If the FRP is locally damaged, moisture and chemicals can reach the steel surface, potentially causing corrosion under insulation. Repair using the original resin system and fiberglass; grind the damaged area, clean, apply primer (if needed), and build up layers. For deep damage exposing steel, inspect the steel for corrosion before repair.

3. What are the service temperature limits for different resin types?

Orthophthalic polyester: -20°C to +80°C, suitable for ambient water and mild chemicals. Isophthalic polyester: -40°C to +100°C, best for improved corrosion resistance. Vinyl ester: -40°C to +180°C, ideal for highly acidic or alkaline media and hot fluids. Epoxy can be used up to +220°C but is less common for filament winding. Always specify your operating temperature and fluid chemistry.

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