Black steel pipe

What Is black steel pipe?

Black steel pipe is made of steel that has not been galvanized. Its name comes from the scaly, dark-colored iron oxide coating on its surface. It’s used in applications that don’t require galvanized steel.

They connected by screwing onto the threaded pipe, after applying a small amount of pipe joint compound on the threads. Larger diameter pipe is welded on rather than threaded. Black steel pipe is cut either with a heavy-duty tube cutter, cut-off saw or by a hacksaw. You can also get Mild Steel ERW Black Pipes that are extensively used for gas distribution inside & outside of the home, and for hot water circulation in boiler systems. Can also be used in usage in potable water or drains waste or vent lines. Please browse our construction pipe and tube directory for a supplier to meet your needs.


William Murdock made the breakthrough leading to the modern process of pipe welding. In 1815 he invented a coal burning lamp system and wanted to make it available to all of London. Using barrels from discarded muskets he formed a continuous pipe delivering the coal gas to the lamps. In 1824 James Russell patented a method for making metal tubes that was fast and inexpensive. He joined the ends of flat iron pieces together to make a tube then welded the joints with heat. In 1825 Comelius Whitehouse developed the “butt-weld” process, the basis for modern pipe making.

Pipe welder

Whitehouse’s method was improved upon in 1911 by John Moon. His technique allowed manufacturers to create continuous streams of pipe. He built machinery that employed his technique and many manufacturing plants adopted it. Then the need arose for seamless metal pipes. Seamless pipe was initially formed by drilling a hole through the center of a cylinder. However, it was difficult to drill holes with the precision needed to ensure uniformity in wall thickness. An 1888 improvement allowed for greater efficiency by casting the billet around a fire-proof brick core. After cooling, the brick was removed, leaving a hole in the middle.


Black steel pipe’s strength makes it ideal for transporting water and gas in rural and urban areas and for conduits that protect electrical wiring and for delivering high pressure steam and air. The oil and petroleum industries use black steel pipe for moving large quantities of oil through remote areas. This is beneficial, since black steel pipe requires very little maintenance. Other uses for black steel pipes include gas distribution inside and outside homes, water wells and sewage systems. Black steel pipes are never used for transporting potable water.

Modern Techniques

Scientific advancement has greatly improved on the butt-weld method of pipe making invented by Whitehouse. His technique is still the primary method used in making pipes, but modern manufacturing equipment that can produce extremely high temperatures and pressure has made pipe making far more efficient. Depending upon its diameter, some processes can produce welded seam pipe at the incredible rate of 1,100 feet per minute. Along with this tremendous increase in the rate of production of steel pipes came improvements in the quality of the final product.

Quality Control

The development of modern manufacturing equipment and inventions in electronics allowed for marked increases in efficiency and quality control. Modern manufacturers employ special X-ray gauges to ensure uniformity in wall thickness. The strength of the pipe is tested with a machine that fills the pipe with water under high pressure to make sure the pipe holds. Pipes that fail are scrapped.

The details about schedule 80 black steel pipe

Manufacturing process of ERW black steel pipes

ERW pipe cold formed from a ribbon of steel pulled through a series of rollers and formed into a tube which is fused through a electric charge.

DSAW pipe (Double Submerged arc welded pipe) Double Submerged Arc Welded (DSAW) steel pipe is available in straight and spiral welded formats and used in a variety of applications.

ERW pipe cold formed from a ribbon of steel pulled through a series of rollers and formed into a tube which is fused through a electric charge.

Common sizes for ERW Steel Pipe range from 2 3/8 inch OD to 24 inch OD in a variety of lengths to over 100 feet.

Surface finishes are available in bare and coated formats and ERW steel pipe processing can be handled on site to customer specifications.


Segregation is the uneven distribution of chemical composition in the steel, in particular harmful elements such as sulfur, phosphorus enrichment in the ingot.

Non-metallic inclusions

Non-metallic inclusions refers to non-metallic inclusions in steel containing impurities such as sulfides and oxides.


Stomata refers iron and carbon monoxide gas effect generated in the pouring can not fully escape and stay in the tiny pores in the ingot.


Shrinkage is due to the liquid steel ingot mold from outside to inside, the volume contraction during solidification bottom-up, because the level drops, the final solidification of liquid steel parts can not be added to form.


Solidification of liquid steel in the order due to different causes stress, tension cracks may appear larger parts.

Fin tubes are used in all sectors asking for an efficient cooling

Carbon steel pipes for cooling

Carbon steel pipe cooling method varies with the material. For most kinds of steel use natural cooling to meet the requirements.

for certain special purpose steel pipe, in order to ensure the requirements of the organization of the state and physical and mechanical properties for certain special purposes, there must be a certain way of cooling and the cooling system. For example, austenitic stainless steel tube, finishing rolling at a certain temperature, and then quenched with water to solution treatment, and then fed to the cooling bed for natural cooling; GCr15 bearing steel so as to have a sheet-pearlite microstructure and prevent the mesh carbonized The precipitate, the use of the ball after annealing step, finish-rolling should be controlled at 850 degrees Celsius or more, then the fast cooling rate of 50-70 ° C / min, and therefore be used in a cold bed hair or spray forced cooling. 

Carbon steel pipe cooling time is the main basis to determine the length of the cooling bed. Steel pipe cooling by radiation and convection heat, proved steel temperature above 500 degrees celsius, mainly by heat radiation. 500 degrees celsius below the convection heat conduction based. It can be considered in order to reduce the the steel cooling time to reduce the cooling bed length, and to improve the operating conditions of the workshop, the forced air cooling bed. A strong urgent need in a 500 degrees celsius.Ventilation cooling time can be reduced by 40-50%. 

Carbon steel pipe cooling ways

The pipe cooling mode vary depending on the chemical composition of the steel pipe, size, and the desired mechanical properties, mill production, cooling going with device conditions. Typically, pipe cooling method: 

  1. natural air cooling. No specific requirements for ordinary steel, is normally in the atmosphere for natural cooling. 
  2. forced cooling. When the smaller cooling bed or mill expansion cooling bed cooling capacity, forced air-cooled, steel pipe requires a certain internal organization and mechanical properties, can be used to control the forced water cooling process. 
  3. slow cooling or quenching. For certain alloy steel pipe (such as bearing steel, stainless steel pipe, etc.), and sometimes slow cooling or quenching steel cooling system in order to improve steel internal organizational structure and its corresponding performance.
en 10305 1 Steel tubes for precision applications power steering

The application and uses of carbon steel pipe

Carbon steel pipe is the most commonly and widely used in the gas project field.

Its main advantages are: high strength, good toughness, bearing stress, impact resistance and rigor, good plasticity, ease of welding and thermal processing, thin wall thickness, to save metal. But its poor corrosion resistance, need to have proper anti-corrosion measures. Steel pipe used in gas engineering are generally made of high quality low carbon steel (Q235) or low-alloy steel (16Mn).

Steel construction is the construction of a new type of energy saving and environmental protection system, known as the 21st century “green building”. The steel construction is light weight, high strength, good seismic performance, energy saving, recycling, building structure, in line with the requirements of the development of energy efficient building and sustained and healthy economic development. The biggest advantage of the steel structure is to bring people to the building function, sensory requirements and economic requirements of a perfect combination. Steel tube structure, with its superior performance in recent years, application of the rapid development of the range of applications involving almost all structural areas, including housing construction, bridges, dams, offshore platform structure and tower masts and so on.

Steel with hollow sections is conveying fluid, such as the transportation of oil, gas, gas, water and some solid materials, pipes, etc.. Compared with the round steel and other solid steel in the flexural torsional strength, light weight, is an economic cross-section steel, widely used in the manufacture of structural parts and mechanical parts, such as drill pipe, automotive transmission, bicycle rack and construction using steel scaffolding. Steel pipe manufacturing annular parts, can improve material utilization, and simplify the manufacturing process, saving material and machining time, such as rolling sleeve ring, jack sets, has been widely manufactured steel pipe.

Large-diameter steel pipe with good adhesion, corrosion resistance, can be resistant to acid, alkali and other chemical corrosion, non-toxic, does not rust, wear resistance, impact resistance, strong permeability, smooth pipe surface will not adhere to any substance, can reduce the transmission of resistance, large diameter steel pipe improve flow and transmission efficiency and reduce the delivery pressure losses. Solvent-free coating, no oozing substance, and thus will not the transmission medium of pollution in order to ensure the purity and health of the fluid at -40 ℃ to +80 ℃ range of thermal cycles used interchangeably, not aging. no cracks, and thus can be used in the cold zone and other harsh environment. Large-diameter steel pipe is pipe that outside diameter is above 1000MM, large diameter coated steel pipe is coated with plastic on the basis of large diameter spiral welded pipe and high-frequency welded pipe from the solvent-free coating, small-diameter steel pipe no oozing substance and therefore not pollution transport media, thus ensuring the purity and health of the fluid, -40 ℃ to +80 ℃ range of thermal cycles used interchangeably, no aging, no cracks, and thus in the cold zone and other harsh environments to use.

The large diameter coated steel pipes are widely used in tap water, natural gas, petroleum, chemical, pharmaceutical, telecommunications, electricity, large diameter steel marine engineering field generally less than the outer diameter of the tubes 89 are collectively referred to as small-diameter steel pipe.

Difference Between Galvanized Pipe & Black Pipe

Both black steel pipe and galvanized pipe are made of steel, however, galvanized pipe has a zinc coating while black pipe does not. As a result galvanized pipe is more durable.

  1. Black pipe is made of steel as is galvanized pipe. The difference is that galvanized pipe is coated with zinc, while black pipe is not.
  2. Black pipe is best used for gas lines, not for water lines because it rusts easily, while galvanized pipe is the safer pipe to use in water lines, but it cannot be used to convey gas.
  3. Black pipe is cheaper than galvanized pipe because of the zinc that is added to galvanized pipe.

The two most common types of steel pipe used to carry water and gas are black pipe and galvanized pipe.

Black pipe is made of steel as is galvanized pipe. The difference is that galvanized pipe is coated with zinc, while black pipe is not.

black steel pipe 02

Black Pipe:

Black pipes are also called steel pipes and are used to carry water and gas from their sources to the end users. It is the pipe that is used by businesses and homes to convey their supply of natural or propane gas.

Black steel pipe is different from galvanized pipe because it is uncoated. The dark color comes from the iron-oxide formed on its surface during manufacturing. The primary purpose of black steel pipe is to carry natural gas into homes and businesses. The pipe is manufactured without a seam, making it a stronger and safer pipe to carry gas. The black steel pipe is also used for fire sprinkler systems because it is more fire-resistant than galvanized pipe.

Galvanized Pipe:

Galvanized steel pipe is covered with a zinc material to make the steel pipe more resistant to corrosion. The primary use of galvanized pipe is to supply water to homes and buildings. The zinc also prevents the buildup of mineral deposits that can clog the water line.

Galvanized pipe is a steel pipe which is covered with zinc. The zinc increases the pipes life expectancy and makes it more resistant to corrosion and mineral deposits in the line. It is a plumbing material that is used in water supply lines and has been used in homes for more than 30 years.

astm a53 galvanized steel pipe 01