Overview of fiberglass pipes

Not so long ago, almost all communications were assembled from metal products. Now, at a time of active development of technology, consumers can evaluate products made from modern materials — fiberglass pipes that do not rust after several years of use. When a solution to this problem was found, the material became most widely known.

Features of fiberglass products

The procedure for the production of such pipes is simple — fiberglass threads are wound on a strong frame in a continuous mode. Such threads are reinforced with a special fiberglass composition. In addition, they are impregnated with a resin mixture, sand and small particles of fiberglass. This manufacturing technology allows the product to last more than 50 years. There is still no information regarding a longer service life, since the first batch produced just “knocked” 50. According to experts, the products are able to serve longer. Fiberglass products are characterized by the following advantages:

• Length of service life;
• Ease of installation work. Additional coupling connection allows you to easily install pipes in communications. There is no need to use welding and quality control of the weld, which saves both money and time;
• Light weight. Fiberglass products, compared to high-quality steel alloy products with similar dimensions, will be 80% lighter;
• Products are not afraid of corrosion, respectively, it is not necessary to use anti-corrosion compounds and impregnations;
• Aggressive components do not affect the material, so it practically does not wear out;
• It is allowed to install fiberglass pipes both in winter and in summer, since the ambient temperature does not affect their properties;
• Environmentally friendly products that do not adversely affect human health and nature;
• Easily withstand temperature fluctuations in the following ranges: from -65 to +155 degrees Celsius.

Fiberglass products are manufactured not only by continuous winding, but also by centrifugal molding.

The technical characteristics of the material largely depend on the number of structural layers. The varieties are as follows:

• The most affordable are single-layer pipes. In this case, the fiberglass layer is not protected by auxiliary coatings;
• Pipes with two layers are distinguished by an outer protective sheath, due to which the impact of harmful substances and ultraviolet rays is significantly reduced;
• Products with three layers are supplemented with a power layer, which is located between the protective shell and the wall structure. The key feature of these pipes is increased strength and resistance to pressure, both external and internal. For this reason, their current cost is quite high.

As for the scope of the described products, it is practically unlimited. The technical characteristics of the products make it possible to use them for laying any communications: water supply, sewerage, oil and gas pipelines, high-voltage equipment.

How to choose fiberglass pipelines

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There are several criteria based on which the right products are selected. All significant characteristics are indicated on the accompanying documentation and on the pipes themselves in the form of markings.

Rigidity and nominal pressure

The resistance of pipes to external loads and internal pressure depends on the material stiffness index. Based on ISO standards, it is customary to classify pipe products according to stiffness classes. The thicker the walls of the fiberglass pipeline, the more rigid it will be.

bonding material

The binder directly affects the performance of the product. In the case of fiberglass, these are polyester and epoxy type additives:

• PEF additives. Thermosetting polyester resins are used to form the walls of the pipes, which are subsequently reinforced with fiberglass and sand. The polymers used in the course of work are characterized by: low toxicity, reliable tenacity with fiberglass and chemical inertness. Composite pipes with PEF additives are not afraid of corrosion and aggressive environment;
• Epoxy resin. Thanks to this binder, the product is more durable. Such pipes are able to withstand temperatures up to +130 degrees Celsius and pressures up to 240 atmospheres. An additional advantage is the almost zero thermal conductivity. This allows you not to spend money on thermal insulation for already assembled pipelines.

Wall construction

Fiberglass pipes can have up to three layers, which significantly affects their technical features and scope of operation:

• 1 layer — no protective lining is provided, so this product is the most affordable. Not suitable for regions with a harsh climate and difficult terrain. It is necessary to install such pipelines carefully, that is, dig a voluminous trench, equip a sandy «cushion», which, ultimately, increases the estimate of work;
• 2 layers — from the inside lined with high-pressure polyethylene. Thanks to such protection, the chemical resistance of the material increases and hermetic performance is improved under external loads. Two-layer modifications installed in oil pipelines have some features: insufficient level of adhesion (the solidity of the walls is broken), the protective film loses its elasticity in the cold, the lining can peel off (if a gas-containing medium is transported through the pipes);
• 3 layers — such a fiberglass pipe consists of: an outer polymer layer (increases mechanical and chemical resistance), a structural layer (improves the strength index) and a liner (inner fiberglass shell). Thanks to the inner layer, the product is smooth, airtight and resistant to cyclic fluctuations in internal pressure.

Pipeline docking technology

Depending on the connection method, 4 groups of fiberglass pipes are distinguished:

• Docking by a socket-and-stud method using a sealing ring. Rubber gaskets are installed in the reciprocal grooves on the end spikes of the products. Landing rings are made on electrical equipment, which allows you to observe their exact dimensions and location;
• Socket-thorn method with a stopper and a seal. If a land line is being built, compensation for the action of axial forces is required. For this, in addition to sealing, a stopper is used. The element is made of a metal cable, polyamides and polyvinyl chloride;
• Connection with flanges. Allows you to connect the composite pipeline with metal products;
• Glue fixing. This method is non-separable — the line ends are processed with reinforcing glass materials. This provides not only a high rate of strength, but also tightness.

Protective inner layer and its marking

Tubular products are manufactured by various methods, so the inner layer may differ in composition. The indicator of resistance of the line to the working environment depends on this.

Companies of the domestic market mark protective coatings in their own way. Depending on the letter designation, the scope of the pipe is determined:

• A — transportation of liquid with abrasives is allowed;
• P — for the supply and removal of cold water;
• X — for transportation of chemically aggressive gas and liquid media;
• G — hot water supply (no more than +75 degrees Celsius);
• C — other liquids with a high acidity index.

As practice shows, a protective layer 3 mm thick is enough.

Technical features of fiberglass pipes, depending on their diameter, are presented in the table below.

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Leading manufacturers and their products

Many companies are engaged in the production of fiberglass products. Below are a few companies whose reputation has been positive for many years.

HOBAS — GRT products with a polyester binder

The enterprises of this company are located in the United States and Europe. The company has earned recognition primarily due to the manufacture of high-quality pipes. The production method is centrifugal casting from fiberglass and polyester resins.

Composite pipes from HOBAS have the following characteristics:

• Diameter — from 150 to 2900 mm;
• Hardness (SN) — from 630 to 10000;
• PN-pressure — from 1 to 25;
• The inner walls of the pipes have a lining anti-corrosion coating;
• Excellent acid resistance.

In addition, the company produces fittings: elbows, adapters, tees and flanged pipes. The cost of pipes starts from 65 rubles (150 mm).

flowtech

The products are manufactured by the Steklokompozit company using the continuous winding method. In the course of work, equipment is used that involves the double supply of resinous substances. Resins of a high-tech type go to the inner layer, and cheaper ones go to the structural layer. Thanks to this technique, consumption is rationalized and production is cheaper.

Amiantite

Flowtite pipes are manufactured from fiberglass, sand and polyester resin in a continuous winding process, resulting in a multi-layer construction. Fiberglass produced by this company consists of 6 layers:

• External winding — non-woven tape;
• Power layer — chopped fiberglass with resin;
• The middle layer is fiberglass with sand and polyester resin;
• Second layer of power;
• Glass threads and resin;
• The protective layer is non-woven fiberglass.

Special studies were carried out, during which the high abrasive resistance of the product was revealed — there were 100 thousand gravel treatment cycles and the protective coating was erased by only 0.34 mm.

Conclusion

Modern technologies make it possible to manufacture pipelines from innovative materials for a wide variety of purposes: these are linear pipes, water pipes, sewers, heating, and so on. When choosing a product, it is necessary to pay attention to the purpose for which it will be used, and then proceed to the technical characteristics. Fiberglass highways have shown that they successfully cope with a wide variety of loads.