Steel pipes come in many types according to different classifications. We have carbon steel, black steel, alloys, and stainless steel as per chemical composition. According to the manufacturing process, steel pipes can be seamless and welded.
Welded steel pipes are manufactured using electric resistance welding (ERW), high-frequency induction welding (HFI), or longitudinal submerged arc welding (LSAW). Steel pipes are also categorized with respect to their properties against corrosion. Stainless steel and black steel are types with inherent corrosion-resistant surfaces, galvanized or painted steel depending on their coatings, such as molten zinc or paint.
Basically, knowing the application or use of the material should be enough to decide what kind of steel pipes to choose or buy. It should be straightforward: purchasing a thick-walled pipe when dealing with high pressures, choosing galvanized or stainless when a steel pipe will be used in a highly corrosive environment, or going seamless for liquid line projects.
However, choosing steel pipe is never simple, especially for significant investments, critical infrastructures, and wherever we wish for the best return value out of our hard-earned money. Project or investment value is not just the totality of the construction cost but the summary of all expenditures throughout its service life, including maintenance costs.
Whether intended for piping, automotive, general construction, or other industries, narrowing the list of appropriate steel pipes requires a closer look and comprehension of their qualities. Below tabulation of crucial information may be of help.
Carbon Steel - Accounts for 90% of total steel production. It is considered the most cost-effective steel pipe due to its relatively affordable iron and carbon elements.
Galvanized Steel - Known as the most durable steel pipe in the market
Black Steel - Considered the most highly stable structured steel pipe
Alloy - It has alloying elements that make steel lighter, sturdier, and more resistant to stress and pressure and also has enhanced weldability and ductility
Stainless Steel - Stainless steel pipes are widely known for their considerable corrosion resistance and aesthetic appearance
Carbon Steel – Alloys of carbon and iron, containing up to about 2% carbon and up to 1.65% manganese by weight
Galvanized Steel – Same components of ferrous steels. They can be iron or steel.
Black Steel – Has low-grade carbon content.
Alloy – Alloying elements like nickel, chromium, manganese, copper, vanadium, molybdenum, silicon, tungsten, and many more, amounting to 1 to 50% by weight
Stainless Steel - Contains between 10 to 20% chromium – the element that prevents corrosion; and a maximum of 0.1 to 1% of carbon. It also contains manganese, silicon, nickel, and molybdenum.
Carbon Steel - Seamless or Welded
Galvanized Steel - Seamless or Welded
Black Steel - Seamless or Welded
Alloy - Seamless or Welded
Stainless Steel - Seamless or Welded
Carbon Steel - 7.85 tons per cubic meter
Galvanized Steel - Weight of base material (iron or steel) + 15% due to zinc coating
Black Steel - 7.80 tons per cubic meter
Alloy - Reduces the weight of pure metals depending on what alloying elements are used.
Stainless Steel - 8.0 tons per cubic meter
Carbon Steel - Ideal for construction applications and other uses like liquid and gas lines under high temperatures, tools, ships, automobiles, and more
Galvanized Steel - Mainly used in the transportation of coal gas, steam, and water
2Equally excellent for a wide range of construction applications, including marine and weather-exposed environments
Black Steel – 1) Preferred in areas that demand high stability like liquid and gas transportation due to high strength and corrosion resistance.
- 2) They are also used in many construction applications
Alloy - *Generally utilized in the piping industry for extreme conditions, as well as in Oil and Gas and power generation, due to its toughness.*Alloy steel pipes also has numerous applications in the building and construction industry
Stainless Steel - Used in industries where corrosion and oxidation resistance are significant and require high strength, including ships energy, poles, water treatment, pharmaceutical, and Oil and Gas applications
Areas of Limitation
Carbon Steel - Not suitable for extreme conditions or high pressure
Galvanized Steel - 1) Not advisable to be used in gas lines because the zinc coating can clog the pipe when it begins to flake;
- 2) Later found to be unrecommended for water transportation due to the contamination developed after years of service.
Black Steel - Less suitable for applications requiring aesthetic appearance
Alloy - Occasions may be rare, but alloys are less recommended when excellent electrical or heat conductivity is required
Stainless Steel - Applications involving contact, friction, or abrasion should be avoided to maintain the integrity of the chromium layer that keeps the material rust and corrosion resistant
Carbon Steel - It is a robust, high-strength, and shock-resistant metal. Unlike many other metals, it does not decay. Carbon steel pipe comes in various sizes, can be bent to curves, and may be utilized almost everywhere. This metal is frequently the most practical choice due to its strength, affordability, and safety.
Galvanized Steel - Galvanized steel pipes are designed to prevent rust and corrosion. Galvanization or zinc coating is less costly than other protective coating methods. It is highly durable; hence it can reach a service life beyond 50 years under normal conditions and at least 25 years under severe and extreme environments.
Black Steel - 1) These steel pipes are manufactured with increased tensile strength and productivity. Fluctuating pressures or shock pressures cannot bend or break them down. In other words, these pipes are shatterproof in transport and in-service;
2) Because of high strength, these pipes can come with thinner walls, maximizing inside diameter or carrying capacity;
3) Alloy steel pipes can prevent fires better than galvanized steel pipes.
Alloy - 1) Alloy steel pipes are corrosion-resistant;
2) have a higher percentage of ductility and weldability.
3) They can be lighter and have a higher melting point than other steel, which is a positive factor in the safety of buildings and structures against fire and seismic activities.
Stainless Steel - 1) Stainless steel pipes are corrosion-heat-impact resistant;
2) They are also favorable for the food industry since they have antimicrobial properties that are genuinely great for transporting food products in processing systems.
*They are also easy to manufacture, install, and maintain. The flexibility of stainless steel makes it possible for manufacturers to generate custom-shaped pipes and pipe fittings. Stainless steel pipes are likewise easy to install, saving industries from lengthy preparation time.
Carbon Steel - It is more prone to rust compared to other steel. Because of its strength, it is more challenging to work with
Galvanized Steel - Galvanized steel pipes corrodes from inside out after some time, resulting in clogged lines and contamination of carried liquids, especially water.
Black Steel - Black steel pipes are not corrosion-resistant and are less attractive.
Alloy - Alloy steel pipes have lower strength compared to carbon steel
Stainless Steel - Stainless steel pipes are more expensive due to the integration of superior alloying materials and the complexity of manufacturing processes and types of machinery