Frp Cylinder

Pipe Structure

The structure of FRP pipe is composed of internal liner, transition layer, structural layer and protective layer

Internal liner: also known as anti‑seepage and anti‑corrosion layer. It plays a key role in anti‑seepage and anti‑corrosion of pipelines. The inner surface layer is formed by 90% resin and 10% surface felt. The thickness of the high and low lining layer is 1.0‑2.0mm according to the pipe diameter and pressure.

Transition layer: formed by two layers of chopped felt and 75 ± 5% resin.

Structure layer: this layer is a filament winding layer, which is the key to product strength. The resin content is 30 ± 5%.

Top coat: also known as outer protective layer. This layer is the outermost layer of the pipeline, which is composed of 100% resin. Its purpose is to prevent the buried pipeline from being eroded by corrosive media in the soil. In addition, toughening agent and anti‑agging agent are added in this layer, which can resist the aging of the pipeline and increase its service life. Its thickness is generally 0.2‑0.5mm.

Pipe Dimensions

Product Characteristics

1. Corrosion resistance and long service life
   • Fiberglass Reinforced Plastic (FRP) possesses exceptional chemical corrosion resistance. Its pipeline products are suitable for conveying various media such as acids, alkalis, salts, and organic solvents. No additional anti-corrosion treatment is required on the inner or outer walls of the pipes, resulting in low maintenance costs.
2. Light weight and excellent physical and mechanical properties
   • The specific gravity of FRP pipes typically ranges from 1.8 to 2.1 g/cm³, making their weight approximately one-fourth that of steel pipes and one-eighth that of concrete pipes. Their mechanical properties, particularly specific strength, surpass those of steel, cast iron, and plastics. Additionally, FRP pipes exhibit excellent physical characteristics: their thermal expansion coefficient is largely comparable to that of steel, while their thermal conductivity is only 0.5% of steel's, making them exceptional thermal and electrical insulators.
3. Smooth inner wall, excellent hydraulic characteristics
   • The inner surface of FRP pipes is exceptionally smooth, with a typical surface roughness coefficient of 0.008, making it nearly "hydraulically smooth." During operation, materials such as steel pipes, cast iron pipes, and concrete pipes often experience localized corrosion, leading to progressively rougher inner surfaces. In contrast, FRP pipes minimize the buildup of deposits and maintain the smoothness of a new pipe surface over time.
   • The excellent hydraulic properties of FRP pipes result in minimal fluid head loss, allowing for the selection of smaller pipe diameters or lower-power pumps. This reduces initial pipeline construction costs, conserves electrical energy, and lowers operational expenses.
4. Precision sealability
   • Sealed with rubber rings.
   • The highly sealed bell-and-spigot joint ensures no leakage.
   • Easy installation reduces setup time.
   • It can accommodate minor directional changes or foundation settlement without requiring additional fittings.
5. Design is flexible and the modification cycle is short
   • FRP pipes are fabricated by winding fiber-reinforced materials impregnated with resin matrix layer by layer under specific process conditions, followed by appropriate curing. The pipe wall exhibits a layered structure, allowing the physical and chemical properties of FRP pipes to be tailored by modifying the resin system or employing different reinforcing materials. This adaptability enables the production of FRP pipes with varying pressure ratings or specific performance characteristics to suit different media and operating conditions. A short modification cycle is a distinctive advantage of fiber-wound composites, a feature unmatched by isotropic metallic pipes.
6. Wide application field
   • Chemical Media Transmission Pipes
   • Small Hydropower Plant Penstocks & Power Plant Circulating Water Pipes (Above Ground)
   • Sewage Collection and Transmission Pipelines
   • Main Water Transmission & Distribution Pipes for Potable Water; Oilfield Water Injection & Crude Oil Transmission Pipes; Thermal Energy Transmission Pipes; Seawater Transmission Pipes
   • Agricultural Irrigation Pipes
   • FRP Equipment (Ventilation & Air Conditioning, Chimneys, Scrubbers, etc.) and Associated Piping
   • Various Process Pipes (Chemical, Papermaking, Wastewater Treatment, Seawater Desalination, Food & Beverage Processing, Pharmaceutical Processes, etc.)