There are two forming methods for fiberglass pipes: one is fixed-length pipes, and the other is continuous pipes. Fiberglass pipes have a series of excellent characteristics such as corrosion resistance, pollution prevention, pest resistance, heat resistance, frost resistance, and good designability, making them widely used in the water supply and drainage industry. Similar to container forming, but for pipes, there is no need for end caps. Generally, a winding angle greater than 54.7 degrees is used at the pipe end to return to nearly 90 degrees, with more fiber accumulation at the pipe end, utilizing the circumferential strength and rigidity of the joints to ensure sealing performance. The connection of large-diameter long-distance transport pipes uses O-ring socket connections, with one end of a single pipe made into a male and the other into a female form. Short-distance above-ground process pipelines mostly use adhesive connections.

Process pipelines require a large number of fittings, such as tees, elbows, etc. High-performance pipe systems and fittings are formed using continuous fiber winding, and the winding of fittings is much more complex than that of straight pipes and containers. Although multi-axis and even robotic winding machines for fittings have been developed, they cannot be promoted in the manufacturing of industrial fittings due to economic reasons. Therefore, the winding of fittings is mostly completed semi-manually. In buried large-diameter pipelines, sand-clamped pipes have been developed to reduce costs and improve resistance to external pressure stiffness, reducing pipeline costs by about 50%.

The Ten Advantages of New Building Materials - Fiberglass

Compared to pipes made of other materials, fiberglass pipes have the following significant advantages:

1. Corrosion-resistant and pollution-free　

Fiberglass pipes can resist the erosion of acids, alkalis, salts, seawater, untreated sewage, corrosive soils or groundwater, and many chemical fluids. Fiberglass pipes have excellent characteristics such as non-toxic, rust-free, odorless, no secondary pollution to water quality, and no need for anti-corrosion, thus being widely used in the water supply and drainage industry.

2. Pollution prevention and pest resistance

The surface of the pipes is made with unsaturated polyester resin, making it clean and smooth, preventing contamination by microorganisms such as barnacles and fungi in seawater or sewage, which would otherwise increase roughness, reduce the cross-section of water flow, and increase maintenance costs. The pipes remain clean and as good as new after long-term use.

3. Heat resistance and frost resistance

At -30°C, it still has good toughness and extremely high strength, and can be used long-term in the range of -50°C to 80°C. Pipes made with specially formulated resin can even work at temperatures above 110°C.

4. Lightweight, high strength, easy transportation, and convenient installation

Fiberglass pipes produced using fiber winding technology have a specific gravity of 1.65-2.0, which is only 1/4 of that of steel, but the circumferential tensile strength of fiberglass pipes is 180-300 MPa, and the axial tensile strength is 60-150 MPa, similar to alloy steel. Therefore, their specific strength (strength/specific gravity) is 2-3 times that of alloy steel, allowing them to be designed to meet various internal and external pressure requirements based on user needs. For the same pipe diameter, the weight of fiberglass pipes is only about 1/2.5 that of carbon steel pipes (steel plate rolled pipes), 1/3.5 that of cast iron pipes, and about 1/8 that of prestressed reinforced concrete pipes, making transportation and installation very convenient. Each section of fiberglass pipe is 12 meters long, reducing joints by two-thirds compared to concrete pipes. Its socket connection method allows for quick and easy installation, while also reducing lifting costs and greatly improving installation speed.

5. Low friction resistance and high transport capacity

The inner wall of fiberglass pipes is very smooth, with low roughness and friction resistance. The roughness coefficient is 0.0084, while the n value for concrete pipes is 0.014 and for cast iron pipes is 0.013. Therefore, fiberglass pipes can significantly reduce fluid pressure loss along the way and improve transport capacity. This can bring significant economic benefits: for the same transport capacity, projects can choose fiberglass pipes with a smaller inner diameter, thus reducing initial project investment; using pipes with the same inner diameter, fiberglass pipes can reduce head loss compared to pipes made of other materials, saving pumping costs. In addition, fiberglass pipes can shorten pumping time and reduce long-term operating costs.

6. Good electrical insulation

Fiberglass is a non-conductor, and the electrical insulation of the pipes is excellent, with insulation resistance ranging from 10^12 to 10^15 Ω.cm, making it most suitable for use in areas with dense power transmission and telecommunications lines and in areas prone to lightning. The thermal conductivity of fiberglass is very low, only 0.23, which is one-fifth that of steel, giving the pipes excellent insulation performance.　　

7. Good wear resistance

A comparative test was conducted by rotating water containing a large amount of mud and sand in the pipes. After 3 million rotations, the wear depth of the inner wall of the pipes was as follows: steel pipes coated with tar and porcelain glaze had a wear depth of 0.53 mm, steel pipes coated with epoxy resin and tar had a wear depth of 0.52 mm, and steel pipes with surface hardening treatment had a wear depth of 0.21 mm, while fiberglass pipes showed good wear resistance.　

8. Low maintenance costs

Due to the aforementioned corrosion resistance, wear resistance, frost resistance, and pollution resistance of fiberglass pipes, projects do not require measures for rust prevention, pollution prevention, insulation, or thermal insulation, nor do they require repairs. For buried pipes, there is no need for cathodic protection, which can save maintenance costs by more than 70%.

9. Good designability

Fiberglass pipes can be designed and manufactured according to various specific requirements of users, such as different flow rates, different pressures, different burial depths, and load conditions, to create pipes of different pressure and stiffness grades.

10. Long service life and good comprehensive benefits

According to laboratory simulation tests, the service life of fiberglass pipes can reach over 50 years. Comprehensive benefits refer to the long-term effects formed by construction investment, installation and maintenance costs, service life, energy savings, and steel savings. The comprehensive benefits of fiberglass pipes are favorable, especially as the diameter increases, the cost decreases. When further considering the long service life of buried pipes, which do not require annual maintenance, the comprehensive benefits are good.