The history of pipes dates back to ancient civilizations. The earliest examples of pipes are hollowed-out wooden and bamboo pipes used in China around 5000 B.C. In ancient Babylon (around 4000 B.C.), clay pipes were used. Copper pipes date back to 3000 B.C. in Egypt, lead pipes to around 2500 B.C., and marble pipes to around 300 A.D. Cast iron pipes, which are still in use today, trace their origins back to the 1500s. Concrete pipes emerged in the 1840s, while steel pipes with flat surfaces became common in the 1880s. The first steel-reinforced concrete composite pipe was produced in 1905, and welded steel pipes were introduced in the 1920s. The first PVC pipe factory was established in 1930, followed by the popular asbestos-cement pipe production in the 1940s. In the 1950s, thermoset plastic composites (CTP) were introduced, and in 1960, high-density polyethylene (HDPE) pipes were produced for the first time. Ductile iron pipes became widely produced in the 1970s and became a primary material for water transmission. Cellulose fiber-reinforced concrete pipes were introduced in the 1980s for wastewater transmission.

In the 1960s, metals and alloys, accounting for 65-70% of total consumption, held the largest share. Today, this percentage has dropped to around 40%, while other material groups (polymers, ceramics, and composites) have relatively increased. For example, today PVC, polyethylene, and polymer-matrix composite pipes and fittings have replaced competitors like concrete, vitrified clay, cast iron, steel, and brass. Water-wastewater pipes vary in diameter and usage areas. In the second half of the 20th century, concrete and clay pipes were heavily used, followed by cast iron (partly ductile iron) and concrete pipes taking second place. In the last quarter of the 20th century, polymeric materials, especially PVC, began to accompany these two materials. Today, PVC pipes (together with other polymers) take the lead in small diameters (below 100 mm). If the consumption figures for these three materials in Germany, a country with a population size similar to ours, are taken as an example for water-wastewater transmission, significant insights can be gained [approximate 2005 values: vitrified clay pipe (ceramic): 200,000 tons, PVC pipe (polymer): 250,000 tons, ductile iron pipe (metal): 250,000 tons]. This result is in line with the relative importance and usage ratios of ceramic, plastic, and metallic materials shown in the figure. In our country, clay pipe production and consumption do not exist, and instead, non-reinforced concrete pipes (ceramics) are widely used by municipalities.

Pipes are classified according to their production method (casting, welding, extrusion, etc.), physical properties (socketed, welded, grooved, etc.), usage areas (water, wastewater, gas, and oil pipes, etc.), fluid states (pressurized, gravity-fed, etc.), and diameters (e.g., 100 mm, 300 mm, etc.). The most accurate and valid classification is based on the material structure. Pipes can be grouped into four categories according to their material structures:

1. Iron-steel and metal pipes (such as steel, ductile iron, copper, and alloys),
2. Plastic pipes (such as PVC, PE, HDPE, PP),
3. Ceramic pipes (such as concrete, vitrified clay),
4. Composite pipes (such as reinforced concrete, CTP).

The pipe sector in Türkiye is growing at a double-digit rate annually. Our share in global production and trade is increasing. Our manufacturers must diversify both their markets and products. Companies must strengthen their financial, technological, and lobbying power.

Pipe material selection depends on excavation conditions (geological conditions), corrosion, temperature, safety requirements, and cost. The main characteristics of pipes include corrosion resistance (internal and external), cleaning factors, sealing, and hydraulic properties.

Pipe material selection should be made according to the structure of the soil and the chemical properties of underground water. The topography of the region will also affect the pipe placement and depth. Based on the list below, it is possible to decide which pipe would be appropriate:

1. Maximum pressure conditions,
2. Dynamic and static loads, overload,
3. Pipe lengths,
4. Soil conditions, soil chemistry, groundwater level, soil stability,
5. Joining material requirements,
6. Installation equipment needs,
7. Physical and chemical properties of wastewater,
8. Sealing/reliability of joints,
9. Size range change requirements,
10. On-site and factory fabrication conditions,
11. Compatibility with the installed system,
12. Condition of chimneys, small chimneys, and other structures in the system,
13. Valves (number, size, and cost),
14. Corrosion/cathodic protection requirements,
15. Repair needs.

In addition to water, wastewater, oil, and natural gas transmission, sectors such as automotive, chemicals, construction, furniture, and power stations continuously increase global pipe demand. The growth recorded in these areas is also fully reflected in the pipe sector. Increasing global trade, urbanization, and growing infrastructure needs are further increasing pipe demand. In addition to the repair needs of aging systems, new investments are expanding the need for pipes. The global pipe demand increase will continue over the next 10 years. The price range, competitive conditions, and input costs will determine this.

Economic properties, mechanical properties, non-mechanical properties, surface properties, production properties, and aesthetic properties are the main criteria used for comparison. Economic properties include price and availability. These are the most important properties for a material. No matter how rich the material’s properties, if it is difficult to obtain or too expensive, using it would not be reasonable from an engineering perspective. Mechanical properties include hardness, strength, fatigue, and creep resistance. Pipe materials should have optimal properties to withstand the effects they will be exposed to. Surface properties and aesthetic values are also important in pipe selection. In summary, pipes used in drinking water distribution systems should have high strength, high wear resistance, corrosion resistance, long lifespan, sealing, resistance to gas and liquid permeability, hygiene, heat resistance, creep resistance, fire resistance, good sound insulation, resistance to earthquake/traffic loads, minimal or no maintenance requirements, and the ability to tolerate pressure fluctuations in networks.

When comparing pipe costs, it is necessary to include not only the material cost but also construction and assembly costs. Pipe cost generally refers to the cost per unit length (USD/meter). The cost may also include fittings, connections, and joining costs. Construction costs will depend on excavation type requirements, special equipment needs, and system changes allowed within the budget or allowance for the current area. Since chimney sizes depend on pipe dimensions, pipe system transition points will also be a significant cost factor.

At present, there is no pipe type that is perfect in every aspect and commercially successful. However, it has become routine (and wrong) to market any member of the pipe family as “perfect” and bring it to market. Suppliers who only rely on catalog information for material selection might face unwanted cost increases. It is essential to remember that every material has its advantages and disadvantages.

The Turkish Society for Infrastructure and Trenchless Technologies is committed to advancing construction methods and infrastructure systems. Through national and international collaboration, the association seeks to provide optimal solutions to manufacturers, users, and researchers alike.