1. Overview of FRP pipes
1.1. FRP and FRP pipesFiberglass (glass fiber reinforced plastics, FRP; glass reinforced plastics, GRP; fiberglass) is a type of composite material using glass fiber or its products as a reinforcing material and plastic as a matrix, also known as glass fiber reinforced plastics. FRP overcomes the shortcomings of various traditional materials and combines the advantages of various traditional materials. It is a new type of material with excellent performance and has been widely used in various industries. FRP pipes are made of this kind of excellent FRP composite material, which is a large type of pipeline structure used to transport various media.
1.2. Basic characteristics of FRP pipesFRP pipelines make full use of the advantages of FRP composite materials and give play to their advantages. They have outstanding advantages in various types of pipeline products. Different FRP pipeline categories have different advantages under different specific conditions of use. Common characteristics:
- High strength, safe and reliable. The strength of glass fiber monofilaments is as high as several gigapascals, and the unidirectional strength after glass fiber reinforced resin can also be as high as 1000 MPa or more. When made into ordinary glass fiber reinforced plastic pipes, the hoop strength of pure hoop winding is generally greater than 500 MPa, which is much higher than ordinary The strength of the steel. Through reasonable design, the safety and reliability of the pipeline structure can be fully guaranteed.
- Strong corrosion resistance and long service life. The most prominent advantage of FRP pipes is corrosion resistance, which has excellent corrosion resistance. Different resins can be used to resist the corrosion of various media such as acids, alkalis, salts and organic solvents without any protection. This is the material itself. Natural corrosion resistance, not so-called anti-corrosion treatment, which is unmatched by other materials, has a long service life.
- The inner wall is smooth and the hydraulic performance is good. The inner wall of FRP pipe is smooth, and the roughness coefficient is only 0.009. Under the same hydraulic gradient, the flow rate of the glass fiber reinforced plastic pipe is 1.56 times that of the concrete pipe with the same diameter; the diameter of the glass fiber reinforced plastic pipe required to transport the same flow at the same hydraulic slope is 84.7% of the concrete pipe diameter. It fully reflects the great advantages of FRP pipes as water supply and drainage pipes.
- Light weight, easy installation and transportation. The density of FRP pipes is generally 1800 ~ 2000kg / m 3. Under the same conditions, the weight of FRP pipes is 1/6 of that of steel pipes and 1/10 of that of concrete pipes. Such a light weight brings great convenience for on-site installation and transportation.
- Strong designability and wide adaptability. The distinguishing feature of composite materials is designability. As a composite material, FRP pipes also have significant features in terms of designability. According to the specific conditions of use, different types of raw materials can be selected, different process layers and structural forms can be used to achieve safer and more economical requirements to meet the conditions of use. In particular, it can adapt to some special harsh environmental conditions and has a wide range of uses. range.
- Energy saving and environmental protection, good comprehensive economy. It is precisely because the glass fiber reinforced plastic pipe has the first few prominent characteristics, the smooth inner wall has a strong water delivery capacity, the head loss is small, and no scaling, so the required pumping power is small, which can significantly save energy and environmental protection, and at the same time has a long service life and corrosion resistance There is basically no maintenance cost throughout the life cycle, and the overall economy is good.
1.3. The main categories of FRP pipesThere are many types of FRP pipes. According to various classification methods, the following categories are mainly included:
- According to the production process: fixed-length wound FRP pipes, continuous wound FRP pipes, centrifugally cast FRP pipes ...
- Divided by the construction method: excavation of buried FRP pipes, FRP roof pipes, FRP traction pipes ...
- According to the use pressure: FRP non-pressure pipeline, FRP medium and low pressure pipeline, FRP high pressure pipeline;
- According to the location of use: FRP underground pipelines, FRP overhead pipelines, FRP underwater pipelines ...
- According to the composition structure: FRP sand pipe, FRP process pipe, FRP reinforced pipe;
- Classification by base material: polyester fiberglass pipe, epoxy fiberglass pipe, phenolic fiberglass pipe ...
- Divided by media category: FRP drinking water pipes, FRP sewage pipes, FRP rainwater pipes, FRP fire water pipes, FRP hot water pipes, FRP seawater pipes, FRP petroleum pipes, FRP gas pipelines, FRP ventilation pipes ...