Black Steel Pipe, Black Carbon Steel Pipe

Black steel pipe is made from carbon steel that has not been galvanised and is called black because of the dark coloured iron-oxide scale formed on its surface. it is used in the oil and petroleum industries to transport large quantities of oil and for the distribution of gas into homes. It is used in transporting water and gas in both rural and urban areas as we as for conduits that protect electrical wiring. It is also used for delivering high pressure steam and air.

The primary purpose of black steel pipe is to carry propane or natural gas into residential homes and commercial buildings. The pipe is manufactured without a seam, making it a better pipe to carry gas. The black steel pipe is also used for fire sprinkler systems because it is more fire-resistant than galvanized pipe.

Black steel pipe sizes:

Product	Out Diameter	Wall Thickness	Length
Black steel pipe	8.7mm-720mm	2.7mm-23.01mm	6mtr-18mtr

What is black carbon steel pipe?
Black carbon steel pipe refers to steel pipe with a higher carbon content, usually above 1.0%. Blackening treatment is a kind of surface oxidation treatment of steel. Its main applicable steel types are carbon steel and low alloy steel. Blackening treatment is to put the workpiece into a very concentrated alkali and oxidant solution and heat it (heating temperature is about 140°C, holding for 1-2 hours), so that a dense Fe304 film is formed on the surface of the steel.

The iron oxide film can isolate the air and prevent the interior of the steel from being oxidized to achieve corrosion resistance. Due to differences in operation and the chemical composition of the metal itself, the colors of this film include black, blue-black, tan, etc.

Uses of black carbon steel pipes:

Black carbon steel is often used for gas or water line pipes because it is low cost and can be welded using common methods. Some long-distance oil pipelines use black carbon steel pipes (such as black mild steel pipes) because such pipes can be connected on site and will not rust quickly. This steel can be used in climates or ground conditions that may accelerate corrosion, but may require additional protection, such as anodes. The anode is an embedded rod made of zinc that corrodes first when connected to the steel pipe.

Classification of black steel pipes:

1. Seamless black carbon steel pipe
Seamless black steel pipes are produced by perforating solid steel billets into hollow cylindrical shapes. Since there are no welds, they are stronger and suitable for high-pressure applications.

2. Welded black carbon steel pipe
Welded (ERW) black steel pipes are cylindrical shapes formed by bending and welding steel plates or steel strips. They are a cost-effective alternative to seamless pipes and are commonly used in a variety of industrial and structural applications.

Advantages of black carbon steel pipes:

The advantages of black steel pipe lie primarily in its mechanical properties, workability, and affordability.

1. High Strength and Durability
Black steel pipe possesses high mechanical strength and can withstand significant pressure, impact, bending, and tensile stresses. This makes it ideal for structural support components such as building steel structures, bridges, and scaffolding.

2. Excellent Workability
Weldability: Carbon steel's ease of welding results in strong and reliable connections, a key reason for its popularity as a primary structural material.
Bendability and Formability: Cold or hot bending is possible using specialized equipment to accommodate various design requirements.
Cutability and Drillability: Cutting, drilling, and threading can be easily performed using conventional tools, making installation and adjustment convenient.

3. Cost-Effectiveness
Compared to stainless steel, galvanized, or other alloy pipes, black steel pipe has lower raw material and production costs, making it one of the most economical steel pipe options, particularly suitable for large-scale projects and budget-sensitive applications.

4. High-Temperature Resistance
In high-temperature environments, its performance is more stable than that of galvanized pipe. While the zinc layer of galvanized pipe evaporates at high temperatures, producing toxic gases, black steel pipe does not have this problem. Therefore, it is often used in fire sprinkler systems (which require subsequent application of fire-retardant paint) and for high-temperature fluid transportation.

5. Wide Availability
As a fundamental industrial product, black steel pipe comes in a wide range of specifications, is readily available, and is readily available, making procurement quick and easy.

Difference between black carbon steel pipe and ordinary carbon steel pipe:

All "black carbon steel pipe" is actually "ordinary carbon steel pipe," but not all "ordinary carbon steel pipe" has a "black" surface (for example, it may be galvanized).

The origin of black steel pipe: During the cooling process after rolling or heat treatment, the hot surface of the steel pipe oxidizes in contact with air, naturally forming a dense but thin black oxide film. This oxide film provides a limited degree of rust protection in the short term and facilitates storage and transportation, but its primary purpose is not ultimate corrosion protection.

Subsequent Processing: Black carbon steel pipe is a semi-finished product, and its final use typically requires subsequent processing, such as:

a. Anti-rust paint: The most common and economical method, used for structural support, scaffolding, etc.
b. Hot-dip galvanizing: Creates "galvanized steel pipe" and is used in applications requiring stronger rust resistance, such as water pipes and guardrails.
c. Spray coating: Provides a more advanced anti-corrosion and aesthetic treatment.

Application of Seamless black carbon steel pipe

1. Low and middle pressure fluid pipeline
2. Casing Pipe
3. Boiler Pipe
4. Petroleum and natural gas industry
5. Chemistry industry
6. Electric industry

FAQ:

1. Will black steel pipe rust?

Of course, black steel pipe will rust. The "black" designation refers to the black iron oxide scale that forms on the pipe's surface during the manufacturing process. This surface oxide scale is not a protective layer and is typically used for corrosion protection or when galvanizing is not required. Without rust prevention, rust will naturally occur.

2. What schedule is black steel pipe?

Black steel pipe is commonly available in schedule 40 or schedule 80. Schedule 40 black steel pipe is most commonly used in general construction, plumbing, and mechanical applications, such as water and gas lines. Schedule 80 black steel pipe has a thicker wall and can handle higher pressures. "Schedule" refers to the pipe's wall thickness, which increases with increasing numbers. "Black" refers to the dark, protective oxide coating on the pipe's surface, typically used for corrosion protection or when galvanizing is not required.

3. Can black steel pipe be used for natural gas?

Yes, but only in certain outdoor, long-distance pipeline applications. Due to its high strength, high-pressure resistance, and cost-effectiveness, black steel pipe is widely used in national or regional natural gas trunk networks, subject to strict conditions. However, the use of ungalvanized black steel pipe is strictly prohibited for any indoor or residential gas piping systems.

4. Can black steel pipe be used for water?

No. Black steel pipe is not suitable for drinking water transportation because its uncoated surface easily rusts, contaminating the water and potentially causing blockages and leaks. Black steel pipe is suitable for non-potable water transportation, such as fire sprinkler systems, heating systems, drainage pipes, and the transportation of natural gas, oil, and steam.

5. Can black steel pipe be welded?

Yes, black steel pipe can be welded. Because it is made of mild steel, it can be welded using common welding methods such as MIG, TIG, flux-cored wire, and stick welding. However, black steel pipe fittings are made of malleable cast iron, making welding more difficult, and the high temperatures may damage the pipe. Proper surface preparation to remove black oxide, paint, or other contaminants is crucial to ensuring weld quality.

6. Where to buy black steel pipe?

Hunan Standard Steel Co., Ltd. (HSCO) is a professional manufacturer and supplier of black steel pipe, with years of industry experience and advanced production equipment. We offer high-quality, reliable steel pipe products in a variety of materials (carbon steel, stainless steel, and alloy steel) to meet the diverse needs of our customers.

Read more: Carbon steel vs Stainless steel or Black Steel Pipe vs Galvanized Steel Pipe