What is a pipe and what are the types of Pipes?

What is a Pipe?
According to the Merriam dictionary, a pipe is defined as a long tube or hollow body for conducting a liquid, gas, or finely divided solid or for structural purposes. From the engineering perspective, pipes are defined as circular tubular products used for conveying fluids (liquids, gases, and fluidized solids). For transporting fluid, pipes are designed for a particular design pressure corresponding to design temperature. Various parameters such as pipe size, pipe thickness, pipe material, pressure withstanding capability, temperature withstanding capability, etc. are considered during piping design.

Applications of Pipes:
Different types of pipes are used in the industrial sector for different purposes. Oil & gas, process industries, chemical & petrochemical industries, food & beverage industries, energy & power industries, refineries & pipeline industries, HVAC industries, steel & infrastructure industries, and daily water sewerage line requires pipes to transport fluid from one place to another. In modern life, the use of pipes is so broad that we cannot imagine any industrial process without pipes.

Types of Pipes:
Due to the application of a large number of industries and processes, the types of pipes are many. The type of pipe is chosen based on various application factors. In this article, we will discuss the different types of pipes that are widely used in industries.

1. Based on the material of the pipes

Pipes can be classified based on the material which is used to produce the pipe during manufacturing. In general, there are two types of pipes:
1. a. Metallic Pipes
1. b. Non-metallic Pipes

1.a. Metallic Pipes
The pipes which are made of metal are known as metallic pipes. They can be categorized into two categories:

1.a.1. Pipes made from ferrous materials
1.a.2 Pipes made from non-ferrous materials

1.a.1 Type of Pipes made from ferrous materials:
Pipes made from ferrous materials are stronger and heavier. These category pipes are most suitable used for heavy-duty work to transport high pressure or high temperature even sometimes heavy fluids. The common application of pipes made from ferrous material is in the oil & gas industries, chemical & petrochemical, energy & power industries, and refineries & piping industries.  These pipes have iron as their main constituent element. Common examples of pipes made from ferrous materials are-

  • Cast Iron pipes
  • Carbon steel pipes
  • Stainless steel pipes
  • Alloy steel pipes
  • Duplex Stainless Steel (DSS) pipes
  • Ductile Iron pipes and so on.

1.a.2 Type of Pipes made from Non-ferrous materials:
Although these pipes are metallic, however iron is not the main constituent of these pipes. These pipes are usually made of copper, aluminum, brass, etc. Non-ferrous material pipes are mostly used in the process piping industry. The main reason behind that is these materials have excellent tensile strength. For example, pipes made of Nickel and Nickel alloys are ideal to use in extreme heat environments because of their resistance property, and it has a passivating oxide coating on their covering. Nickel-copper, nickel- Molybdenum, and nickel-chromium are the most common alloys of Nickel. Nickel and its alloys offer resistance against corrosion and oxidation. This material is suitable to use in applications where alkalis or storing caustic soda is present. It is generally utilized in seawater and mild atmospheric applications. Common pipes made from non-ferrous materials are-

  • Copper and copper alloy pipes.
  • Aluminum and Aluminum alloy pipes.
  • Nickel and Nickel alloy pipes.
  • Titanium and titanium alloy pipes.
  • Zirconium and Zirconium alloy pipes.

1.b. Non-metallic Pipes
Non-metallic pipes are widely used for services where the temperature is not very high. Non-critical services like water industries and drainage systems make use of most of the non-metallic pipes. Common non-metallic and widely used pipes are:

  • Polyethene (PE) plastic pipe/ high-density polyethene (HDPE) Pipes
  • Polyvinyl chloride (PVC) / uPVC/ CPVC Pipes
  • PP pipes
  • Reinforced thermoplastic pipes or RTPs
  • ABS Pipes
  • Composite pipes like GRE/GRP/FRP Pipes
  • Cement and Asbestos Cement Pipes
  • Vitrified clay pipes

The main advantages of reinforced plastic and composite pipes are that they are highly corrosion resistant and durable. While metallic pipes are usually designed for up to 25 years of service. Composite and Reinforced plastic pipes can easily serve up to 50 years. However, their main limitation is the temperature. Non-metallic pipes are not suitable for high-temperature applications. Cement pipes, manufactured from reinforced concretes are usually used for stormwater, gravity service, irrigation industries, and culverts.

2. Types of Pipes based on industry application
As pipes are used in a wide range of industries, therefore these also can be classified based on the industry application. The major types of pipes based on industry applications are-

2.a. Pipes for the Plumbing industry
2.b. Pipes for Chemical and Power industries
2.c. Pipes for the Pipeline industry

2.a Types of Pipes for the Plumbing industry
Pipes are essential to supply water to the kitchen tap or to drain wastewater to the sewage system. These types of drainage and delivery systems have been around since ancient times. In modern times, the common plumbing pipes are PVC pipes, PEX pipes, Copper pipes, ABS pipes, Cast Iron and galvanized steel pipes, etc. They are mainly used for water distribution purposes.

2.b. Types of Pipes for Chemical and Power industries
These types of pipes are suitable for high-temperature and pressure applications. Mainly pipes made from ferrous materials are used in the chemical & petrochemical industries, power & energy industries, steel industries, and oil & gas industries. The chemical and power industry pipes are designed by following codes like ASME B31.3, ASME B31.1, and also other international standards and codes. They are usually selected based on their ability to sustain pressure, temperature, corrosion resistance, etc.

2.c. Pipes for the Pipeline industry
Pipes used in pipeline industries are usually known as line pipes. These pipes are designed by API 5L standard. There are various grades of API 5L pipes that are used to convey oil, gas, or water through pipelines. Other types of pipeline materials are SS, DSS, SDSS, GRE, FRP, etc.

3. Types of Pipes depending on the fluids transported

As you already know the main purpose of pipes is to transport fluids from one point to another, therefore depending on the type of fluid used to transport, pipes can be categorized as-

  • Water Pipes those transport water.
  • Gas pipes transport gaseous substances such as methane gas in the gas power plant.
  • Steam pipes transport steam such as steam in the steam power plant.
  • Vapor pipes transport different vapors of products such as vapor chemicals in the chemical industry.
  • Oil pipes transporting crude or processed oils.
  • Hydrogen pipes carrying hydrogens.

4. Types of Pipes depending on the manufacturing process
Pipes can also be classified based on the manufacturing process. These are again sub-categorized depending on the material of the pipe. For example, Metallic pipes can be categorized as-
4.a. Seamless pipes
4.b. Welded pipe
        4.b.1 Electric resistance welded (ERW) pipes
         4.b.2 Longitudinal Submerged Arc-Welding (LSAW) pipes

4.a. Seamless pipes
The most common types of seamless pipes are:

  • ASTM A106, A333, A53, and API 5L (CS and LTCS pipes)
  • ASTM A312 Series 300 and 400 (SS pipes with grades 304, 316, 321, 347)
  • ASTM A335 Grades P5 to P91 (Alloy steel pipes)
  • ASTM A790/A928 (DSS and SDSS pipes)
  • Nickel alloys (Inconel, Hastelloy, Cupronickel, Monel, Nickel 200)

In general, pipes with a diameter of less than 16 inches are seamless, and larger diameter pipes are welded. Seamless pipes are preferred due to the absence of the weld seam which is considered a weak point. However, they are costlier than welded pipes. Also, for large-diameter pipes, producing seamless pipes becomes difficult.

Carbon steel pipes (A53, A333, A106, and API 5L) have the largest market share since they are cheaper and suitable for a wide range of applications ranging from -29 Deg C to 427 Deg C.

Similarly, Glass Reinforced Plastic (GRP) pipes are classified as-

  • Filament winding GRP pipes
  • Continuous winding GRP pipes
  • Helical Filament winding GRP pipes

4.b. Welded pipe
4.b.1. Electric resistance welded (ERW) pipes
4.b.2. Longitudinal Submerged Arc-Welding (LSAW) pipes

Final Words:

Different types of pipes are used in various industries. The properties of those pipes are different based on their materials and compositions. Therefore, the types of pipes are very broad and there are various parameters that contribute to the classification of pipes. However, the most widely accepted pipe classification is based on the material used to fabricate the pipe. To buy different types of pipes you can visit Iminning Tuberia Industrial.

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