What are carbon steel pipes

What are carbon steel pipes?

Carbon steel pipe is a kind of steel pipe made from ingots or solid round steel that is perforated into a burr tube and then hot rolled, cold rolled or cold punched. Carbon steel is a steel alloy containing iron and carbon. Because of its strength and ability to withstand stress, carbon steel pipe is used in various heavy industries such as infrastructure, ships, distillers and fertilizer equipment.

What is the chemical composition of carbon steel pipe?

Carbon steel is an iron-carbon alloy with a carbon content of 0.0218%-2.11%. It is also called carbon steel. Generally also contains a small amount of silicon, manganese, sulfur, phosphorus. Generally, the higher the carbon content in carbon steel, the greater the hardness and strength, but the plasticity is lower. Because no other alloying elements are added, it is easier to oxidize and rust. The higher the carbon steel content, the greater the hardness, and the higher the strength, relatively speaking, the plasticity will be lower, the price is also relatively low. According to the carbon content, carbon steel can be divided into low carbon steel, medium carbon steel and high carbon steel.

What is low carbon steel?

Low carbon steel generally refers to carbon steel with carbon content between 0.10-0.25%, which is also called soft steel because of its low strength, low hardness and softness. It includes most ordinary carbon structural steel and a part of high-quality carbon structural steel, mostly without heat treatment for engineering structural parts, some by carburizing and other heat treatment for the requirements of wear-resistant mechanical parts.
Low carbon steel annealed organization for ferrite and a small amount of pearlite, its strength and hardness is low, plasticity and toughness is good. Therefore, its cold-forming properties are good can be used to roll the edge, bending, stamping and other methods of cold forming. This steel has good weldability. Low carbon content of low carbon steel hardness is very low, poor machinability, normalizing treatment can improve its machinability.
Low carbon steel has a greater tendency to age, both quenching aging tendency, and deformation aging tendency. When the steel from high temperature faster cooling, ferrite carbon, nitrogen in a supersaturated state, it can also slowly form iron at room temperature carbon and nitrogen, thus increasing the strength and hardness of steel, while plasticity and toughness is reduced, this phenomenon is called quenching aging. Low-carbon steel even if not quenched and air-cooled will also produce aging. Low-carbon steel by deformation produces a large number of dislocations, ferrite carbon, nitrogen atoms and dislocations in the elastic interaction, carbon, nitrogen atoms gathered in the dislocation line around. This combination of carbon and nitrogen atoms and dislocation lines is called the age of Koch’s gas group (Koch’s gas group). It will make the steel strength and hardness increase and plasticity and toughness decrease, this phenomenon is called deformation aging. Deformation aging is more harmful to the plasticity and toughness of mild steel than quenching aging, there are obvious upper and lower yield points on the tensile curve of mild steel. Since the appearance of the upper yield point until the end of the yield extension, there is a surface wrinkle band formed on the surface of the specimen due to uneven deformation, called Lüders band. Many stamped parts are often scrapped as a result. There are two methods to prevent it. A high pre-deformation method, pre-deformed steel placed for a period of time after the stamping will also produce Lüders band, so the pre-deformed steel should not be placed for too long before stamping. The other is to add aluminum or titanium to the steel so that it forms a stable compound with nitrogen to prevent the formation of Koch’s gas cluster caused by deformation aging.

What is medium carbon steel?

Medium carbon steel is a carbon steel with a carbon content of 0.25%-0.60%. It includes most of the high-quality carbon structural steel and part of the ordinary carbon structural steel. Most of these steels are used to make various mechanical parts, and some are used to make engineering structural parts.
Medium carbon steel is a sub-eutectic steel, its annealing organization for pearlite and ferrite. With the increase of carbon content in steel, the number of pearlite in the organization increases, while the number of ferrite decreases. Carbon content greater than 0.40% of the steel quenching organization for martensite; carbon content greater than 0.40%, in addition to martensite and a small amount of residual austenite, the number of residual austenite with the increase of carbon content in steel and increase.

What is high carbon steel?

High Carbon Steel is often called tool steel, with carbon content from 0.60% to 1.70%, and can be quenched and tempered. Hammers, crowbars, etc. are made of steel with 0.75% carbon content; cutting tools such as drills, taps, reamers, etc. are made of steel with 0.90% to 1.00% carbon content.
High-carbon steel has high strength and hardness, high elastic limit and fatigue limit after proper heat treatment or cold-drawing hardening, and fair cutting performance, but poor welding performance and cold plastic deformation ability. Due to the high carbon content, water quenching is prone to cracking, so more than two-liquid quenching, small cross-section parts more oil quenching. This type of steel is generally tempered or normalized at medium temperature after quenching or used in the surface quenching state. Mainly used in the manufacture of springs and wear-resistant parts. Carbon tool steel is basically not added to the alloying elements of high carbon steel, but also tool steel in the lower cost, hot and cold workability, the use of a wide range of steel. Its carbon content in 0.65 a 1.35%, is specifically used to make tools of steel. The density of high carbon steel is 7.81g/cm³. It can be used in the production of fishing gear.

What is the difference between low carbon steel, medium carbon steel and high carbon steel?

Low carbon steel, also known as soft steel, has a carbon content from 0.10% to 0.30%. Low carbon steel is easy to accept various processes such as forging, welding and cutting, and is commonly used for making chains, rivets, bolts, shafts, etc.
Carbon steel with carbon content below 0.25% is also called soft steel because of its low strength, low hardness and softness. It includes most of the ordinary carbon structural steel and a part of high quality carbon structural steel, mostly without heat treatment for engineering structural parts, some by the carbon and other heat treatment for the requirements of wear-resistant mechanical parts.
Low carbon steel annealed organization for ferrite and a small amount of pearlite, its strength and hardness is low, plasticity and toughness is good. Therefore, its cold forming properties are good and can be cold formed by rolled edge, bending, stamping and other methods. This steel fin has good weldability. Low carbon content of low carbon steel hardness is very low, poor machinability, quenching treatment can improve its machinability.
Low carbon steel is generally rolled into angles, channels, I-beams, steel pipes, steel strips { steel plates, used to make a variety of building components, containers, boxes, furnace bodies and agricultural』machinery, etc. High-quality low carbon steel rolled into thin plates, the production of automobile cabs, generator covers and other deep-drawn products; also rolled into bars, used to make strength requirements not i mechanical parts. Low carbon steel in use before the general without heat treatment, carbon content { in 0.15% or more by carburization or cyanide treatment, for the requirements of the surface layer { high, good wear resistance of the shaft, bushings, sprockets and other parts.
Low carbon steel is restricted in use due to its low strength. Properly increase the manganese content of carbon steel, and add trace vanadium, titanium, niobium and other alloying elements, can greatly improve the strength of steel. If you reduce the carbon content of steel and add a small amount of aluminum, { amount of boron and carbide forming elements, you can get ultra-low carbon bainite group enough its strength is very high, and maintain good plasticity and toughness.
Medium carbon steel is 0.25% -0.60% carbon steel. There are a variety of products such as sedimentary steel, semi-sedimentary steel, boiling steel. In addition to carbon can also contain a small amount of manganese (0.70% – 1.20%). According to the quality of the product is divided into ordinary carbon structural steel and high-quality carbon structural steel. Good hot working and cutting performance, welding performance is poor. Strength, hardness than low carbon steel, while plasticity and toughness is lower than low carbon steel. Can be used directly without heat treatment, hot-rolled, cold-drawn material, or after heat treatment. Quenched and tempered medium carbon steel has good overall mechanical properties. Can achieve the highest hardness of about HRC55 (HB538), σb for 600-1100MPa. so in the medium strength level of a variety of uses, medium carbon steel is the most widely used, in addition to as a building material, but also a large number of manufacturing a variety of mechanical parts.
Medium carbon steel contains higher carbon content than low carbon steel, higher strength, poor weldability. Commonly used are 35# steel, 45# steel, 55# steel. The main features of medium carbon steel electrode arc welding and its castings welding patch are as follows.

• (1) The heat-affected zone is prone to hardened organization. The higher the carbon content, the greater the plate thickness, the greater this tendency. If the welding materials and process specifications are not properly selected, it is easy to produce cold cracking.
• (2) Because of the high carbon content of the base metal, the carbon content of the weld is also higher, which is prone to thermal cracking.
• (3) Because of the increase in carbon content, so the sensitivity to porosity increases. Therefore, the deoxidation of welding materials, base metal degreasing and rust removal, drying of welding materials, etc., more stringent requirements.

High-carbon steel is often called tool steel, with carbon content from 0.60% to 1.70%, and can be hardened and tempered. Hammers, crowbars, etc. are made of steel with 0.75% carbon content; cutting tools such as drills, taps, reamers, etc. are made of steel with 0.90% to 1.00% carbon content. Welding of high carbon steel
High-carbon steels have poor welding properties due to their high carbon content. Its welding has the following characteristics.

• (1) Poor thermal conductivity, the weld zone and the unheated part between the significant temperature difference, when the melt pool cools sharply, the internal stress caused in the weld, it is easy to form cracks.
• (2) More sensitive to quenching, the near seam zone is extremely susceptible to the formation of martensitic tissue. As a result of tissue stress, the near seam zone produces cold cracks.
• (3) Due to the influence of high welding temperature, the grain grows quickly, carbide is easy to accumulate and grow on the grain boundaries, making the weld fragile and reducing the strength of the welded joint.
• (4) High-carbon steel welding is more likely to produce thermal cracking than medium-carbon steel.

Chemical Properties of Carbon Steel Pipes & Tubes

ASTM A53	Composition, max, %
	Elt	C	Mn	P	S
	Type S (seamless pipe)
	Gr. A	0.25	0.95	0.05	0.045
	Gr. B	0.3	1.2	0.05	0.045
	Type E (electric-resistance-welded)
	Gr. A	0.25	0.95	0.05	0.045
	Gr. B	0.3	1.2	0.05	0.045
	Type F (furnace-welded pipe)
	Gr. A	0.3	1.2	0.05	0.045
	Composition, max, %
	Elt	Cu (1)	Ni (1)	Cr (1)	Mo (1)	V (1)
	Type S (seamless pipe)
	Gr. A	0.4	0.4	0.4	0.15	0.08
	Gr. B	0.4	0.4	0.4	0.15	0.08
	Type E (electric-resistance-welded)
	Gr. A	0.4	0.4	0.4	0.15	0.08
	Gr. B	0.4	0.4	0.4	0.15	0.08
	Type F (furnace-welded pipe)
	Gr. A	0.4	0.4	0.4	0.15	0.08
	Notes: The total composition for these five elements shall not exceed 1.00%.
ASTM A105	Composition, %
	Elt	C	Mn	P	S	Si
		0.35	0.6	0.035	0.04	0.1
		max	1.05	max	max	0.35
	Composition, %
	Elt	Cu	Ni	Cr	Mo	V
		0.4	0.4	0.3	0.12	0.08
		max (1)	max (1)	max (1-2)	max (1-2)	max
	Notes: The sum of Copper, Nickel, Niobium, Molybdenum and Vanadium shall not exceed 1.00%. The sum of Niobium and Molybdenum shall not exceed 0.32%. Note.. For each reduction of 0.01% below the specified carbon maximum (0.35%), an increase of 0.06% Manganese above the specified maximum (1.05%) will be permitted up to a maximum of 1.35%.
ASTM A106	Composition, %
	Elt	C	Mn	P	S	Si
		max		max	max	min
	Gr. A	0.25 (1)	0.27	0.035	0.035	0.1
			0.93
	Gr. B	0.30 (2)	0.29	0.035	0.035	0.1
			1.06
	Gr. C	0.35 (2)	0.29	0.035	0.035	0.1
			1.06
	Composition, %
	Elt	Cr	Cu	Mo	Ni	V
		max (3)	max (3)	max (3)	max (3)	max (3)
	Gr. A	0.4	0.4	0.15	0.4	0.08
	Gr. B	0.4	0.4	0.15	0.4	0.08
	Gr. C	0.4	0.4	0.15	0.4	0.08
	Notes: For each reduction of 0.01% below the specified Carbon maximum, an increase of 0.06% Manganese above the specified maximum will be permitted up to a maximum of 1.35%. Unless otherwise specified by the purchaser, for each reduction of 0.01% below the specified Carbon maximum, an increase of 0.06% Manganese above the specified maximum will be permitted up to a maximum of 1.65%. These five elements combined shall not exceed 1%.
ASTM A216	Composition, % max
	Gr.	C	Mn	P	S	Si
	WCA	0.25 (1)	0.70 (1)	0.04	0.045	0.6
	UNS J02502
	WCB	0.30 (2)	1.00 (2)	0.04	0.045	0.6
	UNS J03002
	WCC	0.25 (3)	1.20 (3)	0.04	0.045	0.6
	UNS J02503
	Composition, % max
	Gr.	C	Mn	P	S	Si
	WCA	0.25 (1)	0.70 (1)	0.04	0.045	0.6
	UNS J02502
	WCB	0.30 (2)	1.00 (2)	0.04	0.045	0.6
	UNS J03002
	WCC	0.25 (3)	1.20 (3)	0.04	0.045	0.6
	UNS J02503
	Notes: For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% manganese above the specified maximum will be permitted up to a maximum of 1.10%. For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% Mn above the specified maximum will be permitted up to a maximum of 1.28%. For each reduction of 0.01% below the specified maximum Carbon content, an increase of 0.04% manganese above the specified maximum will be permitted to a maximum of 1.40%.
ASTM A234	Composition, %
	Gr.	C	Mn	P	S	Si
				max	max
	WPB	0.3	0.29	0.05	0.058	0.1
	(1 2 3 4 5)	max	1.06			min
	WPC	0.35	0.29	0.05	0.058	0.1
	(2 3 4 5)	max	1.06			min
	WP1	0.28	0.3	0.045	0.045	0.1
		max	0.9			0.5
	WP12 CL1	0.05	0.3	0.045	0.045	0.6
		0.2	0.8			max
	WP12 CL2	0.05	0.3	0.045	0.045	0.6
		0.2	0.8			max
	WP11 CL1	0.05	0.3	0.03	0.03	0.5
		0.15	0.6			1
	WP11 CL2	0.05	0.3	0.04	0.04	0.5
		0.2	0.8			1
	WP11 CL3	0.05	0.3	0.04	0.04	0.5
		0.2	0.8			1
	WP22 CL1	0.05	0.3	0.04	0.04	0.5
		0.15	0.6			max
	WP22 CL3	0.05	0.3	0.04	0.04	0.5
		0.15	0.6			max
	WP5 CL1	0.15	0.3	0.04	0.03	0.5
		max	0.6			max
	WP5 CL3	0.15	0.3	0.04	0.03	0.5
		max	0.6			max
	WP9 CL1	0.15	0.3	0.03	0.03	1
		max	0.6			max
	WP9 CL3	0.15	0.3	0.03	0.03	1
		max	0.6			max
	WPR	0.2	0.4	0.045	0.05
		max	1.06
	WP91	0.08	0.3	0.02	0.01	0.2
		0.12	0.6			0.5
	WP911	0.09	0.3	0.02	0.01	0.1
		0.13	0.6			0.5
	Composition, %
	Gr.	Cr	Mo	Ni	Cu	Others
	WPB	0.4	0.15	0.4	0.4	V 0.08
	(1 2 3 4 5)	max	max	max	max	max
	WPC	0.4	0.15	0.4	0.4	V 0.08
	(2 3 4 5)	max	max	max	max	max
	WP1		0.44
			0.65
	WP12 CL1	0.8	0.44
		1.25	0.65
	WP12 CL2	0.8	0.44
		1.25	0.65
	WP11 CL1	1	0.44
		1.5	0.65
	WP11 CL2	1	0.44
		1.5	0.65
	WP11 CL3	1	0.44
		1.5	0.65
	WP22 CL1	1.9	0.87
		2.6	1.13
	WP22 CL3	1.9	0.87
		2.6	1.13
	WP5 CL1	4	0.44
		6	0.65
	WP5 CL3	4	0.44
		6	0.65
	WP9 CL1	8	0.9
10		1.1
WP9 CL3	8	0.9
	10	1.1
WPR			1.6	0.75
			2.24	1.25
WP91	8	0.85	0.4		V 0.18
	9.5	1.05	max		0.25
					Nb 0.06
					0.1
					N 0.03
					0.07
					Al 0.02 max (6)
					Ti 0.01 max (6)
					Zr 0.01 max (6)
WP911	8	0.9	0.4		V 0.18
	9.5	1.1	max		0.25
					Nb 0.06
					0.1
					N 0.04
					0.09
					Al 0.02 max (6)
					B 0.0003
					0.006
					W 0.9
					1.1
					Ti 0.01 max (6)
					Zr 0.01 max (6)
Notes: Fittings made from bar or plate may have 0.35 max carbon. Fittings made from forgings may have 0.35 max Carbon and 0.35 max Silicon with no minimum. For each reduction of 0.01% below the specified Carbon maximum, an increase of 0.06% Manganese above the specified maximum will be permitted, up to a maximum of 1.35%. The sum of Copper, Nickel, Niobium, and Molybdenum shall not exceed 1.00%. The sum of Niobium and Molybdenum shall not exceed 0.32%. Applies both to heat and product analyses.

The influence of chemical elements in the carbon steel pipe material

Steel is an alloy of iron and carbon. Carbon steel is a series of alloys of carbon and iron with about 1% carbon and up to 1.65% manganese, with specific amounts added for deoxidation and residuals of other elements.
The functions and elements of various parts of steel are introduced.

• 1. Carbon, silicon, manganese, sulfur, phosphorus is the main impurity elements in pig iron and carbon steel, commonly known as the “five elements”. Because they have a great impact on the performance of steel, the general analysis needs to determine them.
• 2. Chromium (Cr): In structural steel and chromium, chromium can significantly improve the strength, hardness and wear resistance, but at the same time reduce plasticity and toughness. Chromium can improve the oxidation resistance and corrosion resistance of steel, so it is an important alloying element for stainless steel and heat-resistant steel.
• 3. Nickel (Ni): Nickel can improve the strength of steel, while maintaining good ductility and toughness. Nickel has high corrosion resistance to acids and bases, rust resistance and heat resistance at high temperatures. However, because nickel is a scarce resource, other alloying elements should be used instead of nickel-chromium steel.
• 4. Molybdenum (Mo): molybdenum can refine the grain of steel, improve hardenability and thermal strength, and maintain sufficient strength and creep resistance at high temperatures (long-term stress at high temperatures, deformation occurs, called creep). The addition of molybdenum to structural steel improves mechanical properties. It can also inhibit the brittleness of alloy steels due to fire. The red color of tool steels can be improved.
• 5. Titanium (Ti): Titanium is a strong deoxidizer in steel. It can make the internal organization of steel dense and refine the grain force; reduce aging sensitivity and cold brittleness. Improve the welding performance. In the chromium 18 nickel 9 austenitic stainless steel to add the appropriate titanium can avoid intergranular corrosion.
• 6. Vanadium (V): Vanadium is an excellent steel deoxidizer. Adding 0.5% vanadium to steel can refine the grain structure and improve strength and toughness. Vanadium and carbon form carbides to improve the high temperature and pressure of hydrogen corrosion resistance.
• 7. Tungsten (W): Tungsten has a high melting point and a high specific gravity. It is a precious metal element. Tungsten and carbon form tungsten carbide, which has high hardness and wear resistance. Adding tungsten to the tool steel can significantly improve the red hardness and thermal strength of tools and forging dies.
• 8. Niobium (Nb): niobium can refine the grain, reduce the steel superheat sensitivity and tempering brittleness, improve strength, but plasticity and toughness is reduced. Adding bismuth in ordinary low-alloy steel can improve its resistance to atmospheric corrosion and high temperature hydrogen, nitrogen and ammonia corrosion. Niobium can improve welding properties. Twisting of austenitic stainless steel can prevent intergranular corrosion.
• 9. Cobalt (Co): Cobalt is rare and valuable for special steels and alloys, such as hot strength steels and magnetic materials.
• 10. Copper (Cu): Copper can improve the strength and toughness, especially atmospheric corrosion. The disadvantage is that it is prone to thermal embrittlement during hot work, and the copper content is significantly reduced by more than 0.5%. When the copper content is less than 0.50%, there is no effect on weldability.
• 11. Aluminum (Al): Aluminum is a common deoxidizer in steel. Small amounts of aluminum are added to steel to refine grain size and improve impact toughness, such as 08Al steel for deep-drawn thin plates. Aluminum also provides oxidation resistance and corrosion resistance. Aluminum combines with chromium and silicon to significantly improve the steel’s resistance to high temperatures and corrosion. The disadvantage of aluminum is that it affects the hot workability, weldability and machinability of steel.
• 12. Boron (B): add trace amounts of boron to the steel can improve the denseness and hot rolling properties of steel, and improve the strength.
• Nitrogen (N): Nitrogen can improve the strength, low-temperature toughness and weldability of steel, and improve the aging sensitivity.

Types of Carbon Steel Pipes

In the market, there are a wide variety of carbon steel pipes, and we can classify them according to different production processes. There are four main categories: seamless carbon steel pipes, straight seam carbon steel pipes, spiral carbon steel pipes, and high-frequency welded carbon steel pipes.

Seamless steel pipes

Seamless steel pipes are manufactured without a seam or welding joint, resulting in a uniform structure throughout the pipe. This homogeneity provides superior strength and resistance to high pressure, making seamless pipes ideal for high-stress applications. There are two primary types of seamless steel pipes:

Hot rolled seamless steel pipes

Hot rolled seamless steel pipes are produced by heating a solid billet or round bar and then rolling it into a hollow tube. This process involves high temperatures, typically above 1,100°C, which ensures the pipe’s uniformity and precise dimensions. Hot rolled seamless pipes are commonly used in high-pressure applications, such as oil and gas transportation, power generation, and petrochemical industries.

Cold drawn seamless steel pipes

Cold drawn seamless steel pipes are manufactured using a process that involves drawing a solid billet or round bar through a series of dies and over a mandrel. This technique results in tighter tolerances, better surface finish, and higher mechanical properties compared to hot rolled seamless pipes. Cold drawn seamless pipes are ideal for precision applications, such as hydraulic systems, automotive parts, and boiler tubes.

Welded steel pipes

Welded steel pipes are made by joining steel plates, strips, or coils using a welding process. These pipes are cost-effective and can be produced in larger diameters compared to seamless pipes. Welded steel pipes are commonly used in low to medium pressure applications, such as water and gas transportation, structural and mechanical purposes, and general industrial use. There are several types of welded steel pipes:

High frequency welded steel pipes

High frequency welded steel pipes are manufactured using an electric resistance welding (ERW) process that employs high-frequency electrical currents to heat the edges of the steel strip, which are then fused together. This method produces a strong, continuous bond along the length of the pipe. High frequency welded pipes are commonly used in the oil and gas industry, water pipelines, and structural applications.

Longitudinal submerged arc welded steel pipes

Longitudinal submerged arc welded (LSAW) steel pipes are made by bending a steel plate and welding the long seam using a submerged arc welding process. This method produces pipes with a straight, single longitudinal seam and is ideal for large diameter and thick-walled pipes. LSAW pipes are often used in the oil and gas industry, water transmission lines, and structural applications.

Spiral welded steel pipes

Spiral welded steel pipes are produced by winding a steel coil around a mandrel and welding the helical seam using a submerged arc welding process. This method results in pipes with a continuous, spiral-shaped seam and is suitable for large diameter and high-pressure applications. Spiral welded pipes are commonly used in the oil and gas industry, water pipelines, and construction projects.

Electric Fusion Welded (EFW) steel pipes

Electric Fusion Welded (EFW) steel pipes are produced by fusing steel plates together using an electric arc. The process involves the use of high voltage electrical currents to generate heat, melting the edges of the steel plates and forming a continuous bond. EFW pipes are typically used in high-pressure applications, such as power plants, chemical and petrochemical industries, and oil and gas transportation.

Double Submerged Arc Welded (DSAW) steel pipes

Double Submerged Arc Welded (DSAW) steel pipes are manufactured using a similar process to LSAW pipes, but with an additional submerged arc welding pass on the inside and outside of the seam. This double welding process increases the strength and durability of the pipe, making it suitable for high-pressure and high-stress applications. DSAW pipes are commonly used in the oil and gas industry, water transmission lines, and offshore structures.

Pipe coatings and linings

Carbon steel pipes are often coated or lined to improve their resistance to corrosion, wear, and abrasion. These protective layers help extend the life of the pipe and reduce maintenance costs. Some common coatings and linings for carbon steel pipes include:

Fusion Bonded Epoxy (FBE) coating

Fusion Bonded Epoxy (FBE) is a powder coating that is applied to the pipe’s surface and then heated to form a hard, protective layer. FBE coatings provide excellent corrosion resistance and can withstand harsh environmental conditions. They are commonly used for pipelines transporting water, oil, gas, and chemicals.
Polyethylene (PE) coating
Polyethylene (PE) coatings are made from a thermoplastic material that is applied to the pipe’s surface, providing a durable and flexible protective layer. PE coatings offer excellent corrosion resistance, impact resistance, and abrasion resistance. They are commonly used for gas and water pipelines.
Cement mortar lining
Cement mortar lining is a mixture of cement, sand, and water that is applied to the interior of carbon steel pipes. This lining provides corrosion protection, reduces internal friction, and prevents the formation of tuberculation. Cement mortar lining is commonly used in water pipelines and sewage systems.

What are applications of carbon steel pipes?

Carbon steel pipes are widely used for many industries, ranging from oil and gas to power generation, to chemical and industrial. Carbon steel pipes are commonly used in construction, petrochemical industry and the power generation industry. The use of carbon steel pipe depends on its application requirements.
The following is a list of some applications of carbon steel pipes:
Oil & Gas Industry
The oil and gas industry is a major consumer of carbon steel pipes. These pipes are used in the oil and gas industry to transport oil and gas from one place to another. Carbon steel pipes are also used in pipelines, which carry natural gases between processing plants or other facilities. They are also installed at drilling rigs, where they allow drilling fluids to flow back into the ground safely after being used for drilling operations.
Power plants
Carbon steel pipes are used in power plants to transport high pressure steam. The pipes also need to withstand the heat generated by the process of generating electricity, so carbon steel is an excellent choice for this purpose.

Water and wastewater
Carbon steel pipes are used in water supply systems, sewage treatment plants, and stormwater management systems, due to their corrosion resistance and ability to withstand high pressures.
Structural and mechanical
Carbon steel pipes are used in the construction of buildings, bridges, and other structures, as well as in various mechanical applications, such as automotive components and machinery.
Construction
Construction is one of the biggest uses of carbon steel pipes. Carbon steel pipes are used in construction for water and gas pipelines, drainage systems and sewer systems.
The most common size of pipe used in building construction is 2 inches (51 mm) in diameter. This allows for higher flow rates than with smaller diameters.
The petrochemical industry
Carbon steel pipes are used in the petrochemical industry, which refers to the production of chemicals from crude oil and natural gas. Carbon steel pipes are used to transport oil and gas, as well as chemicals, steam and water.
Automobile Industry
Carbon steel pipe is used in automobile exhaust systems. Carbon steel pipes are components of the exhaust system of an automotive engine. They are lined with a ceramic coating to protect them from corrosion, and they have a flange at one end that allows connection to other components of the piping system.

The Advantages Of Carbon Steel Pipes

Carbon steel pipes have a high strength with good weight to perform. They are durable and leak proof, corrosion resistant and non-magnetic. These pipes resist water, steam and acid. Carbon steel pipes are also resistant to chemicals. They can be used for a variety of applications such as heating, cooling and refrigeration systems, air conditioning equipment, chemical processing plants etc..
The durability of carbon steel pipes is also much higher than that of other pipes.
Carbon steel pipes are also used in various industries and applications due to their high resistivity to pressure. Their durability is also much higher than that of other pipes. They are not affected by corrosion, and the life of carbon steel pipes may last for several decades or centuries depending on how they are maintained and used. Due to its durability, carbon steel pipes have now become a preferred choice for many industries as well as individuals who use them on a regular basis at home or work.
The carbon steel pipes are leak proof and it resists corrosion and has got high performance ratio.
Carbon steel pipes are leak proof and resist corrosion. It is a high performance material which has got a high performance ratio. Carbon steel pipes are economical and strong due to its carbon content (0.2%). Carbon Steel Pipes can be used in any condition but it is recommended not to use them in overhead applications as they have low ductility and could get damaged easily.
Carbon Steel Pipes have excellent resistance against chemical attacks because of their uniform composition of elements such as iron, carbon, manganese, silicon etc., also called alloy steels or non-alloy steels because they do not contain any other element except those mentioned above.
The carbon steel pipes can be manufactured according to the specifications of the customers and the manufacturers can even alter the specifications if required.
Carbon steel pipes are manufactured to suit the requirements of the customers. The carbon steel pipes can be manufactured according to the specifications of the customers and the manufacturers can even alter the specifications if required.
The carbon steel pipes are non magnetic in nature and strong enough to handle electrical shocks. Thus, there is a need for a nonmagnetic pipe arises frequently.
Since these products are made using carbon as their base, they also have high tensile strength that helps them withstand pressure very well without breaking down easily making it one of its greatest advantages over other materials like PVC or PE which tend not be able to withstand even minimal amount of pressure applied on their structure.
Since it’s resistant to water, steam (except when highly concentrated) and acid, carbon steel pipes are used extensively in many industries like chemical plants and oil refineries where they have to withstand intense heat or corrosive chemicals.
Carbon steel pipes are resistant to water, steam and acid and thus are used in many industries like automobile, sugar, paper, paper pulp, electronics etc. They have high tensile strength which allows them to bear large pressure without getting damaged. These pipes can withstand both internal as well as external pressures up to 3 MPa.
Carbon steel pipes can be used in a variety of applications due to their high resistivity to pressure.
Carbon steel pipes are resistant to water and steam, and are also suitable for use in acid solutions. They have excellent mechanical properties such as strength, toughness and ductility that make them ideal for use in many industries including petrochemical refineries, oil and gas production plants, chemical manufacturing facilities etc. In addition to these advantages, carbon steel pipes have excellent resistance against corrosion making them leak proof while providing strength at high temperatures (up to -400°C).

Standards of steel pipes

Steel pipes by standards include ASTM, JIS, DIN, Customers for international, etc…

American Petroleum Institute (API) standards
API 5L is the specification for line pipe used in the oil and gas industry, while API 5CT covers tubing and casing for oil and gas wells.
American Society for Testing and Materials (ASTM) standards
ASTM A53 is the standard specification for welded and seamless carbon steel pipes for pressure and structural applications. ASTM A106 covers seamless carbon steel pipes for high-temperature service, and ASTM A333 is the specification for seamless and welded carbon steel pipes for low-temperature service.
International Organization for Standardization (ISO) standards
ISO 3183 is the specification for steel pipe for pipeline transportation systems in the petroleum and natural gas industries.

We can produce and sell cold drawn and hot rolled steel pipes as well as cold drawn special section steel pipes, which are widely used in petrochemical, boiler, automobile, machinery, construction, and other industries.

The Surface Of Stainless Steel Tubing

Pickled surface carbon steel pipe (polished)
The surface of carbon steel pipe is pickled. The pipe is pickled and passivated after solid solution annealing, and then a passivated coating is obtained to improve corrosion resistance. If there are no special requirements for the surface, the tube will undergo a grinding process.
Polishing carbon steel pipes
Polishing here is mechanical polishing and includes both inner and outer surfaces. The roughness can be at least 0.4µm (16µin) or 300 grit produced by polishing. Mechanical polishing uses fully automated polishing machines to control surface accuracy and roughness for food grade and bioengineering needs.
Bright Annealed/Barium Tubes
BA tubes are bright annealed stainless steel tubes, which is a different heat treatment process from ordinary stainless steel solution annealing to obtain better accuracy and surface roughness. BA tubes do not need to be pickled again and their roughness can meet the polishing accuracy requirements, but the cost is higher than mechanically polished stainless steel tubes.
Electrolytic polishing/EP tube
Stainless steel EP tubes are high purity, high precision tubes used in demanding environments such as bioengineering, semiconductors, laboratories and precision instruments. The inner surface roughness of our EP tubes can reach 0.2 to meet the stringent requirements of various working conditions.

The production process of carbon steel pipe

According to the manufacturing process of seamless carbon steel pipe, seamless carbon steel pipe can be divided into hot-rolled seamless carbon steel pipe and cold-drawn seamless carbon steel pipe.

Generally, the production process of seamless steel pipe can be divided into cold drawing and hot rolling. The production process of cold-rolled seamless steel pipe is generally more complex than hot rolling. The pipe blank must first be subject to three roll continuous rolling, and the sizing test must be carried out after extrusion. If the surface does not respond to the crack, the round pipe must be cut by a cutter, and the billet with a length of about one meter must be cut. Then enter the annealing process. Acid pickling is required for annealing. During acid pickling, pay attention to whether there is a large number of bubbles on the surface. If there is a large number of bubbles, it means that the quality of the steel pipe cannot meet the response standard. The appearance of cold-rolled seamless steel pipe is shorter than that of hot-rolled seamless steel pipe. The wall thickness of cold-rolled seamless steel pipe is generally smaller than that of hot-rolled seamless steel pipe, but the surface looks brighter than that of thick wall seamless steel pipe. The surface is not too rough, and the diameter is not too much burr. Hot rolled seamless steel pipes are generally delivered after heat treatment. After quality inspection, the hot-rolled seamless steel pipe should be strictly selected by the staff by hand. After quality inspection, the surface should be oiled, followed by many cold drawing experiments. After hot rolling, the perforation experiment should be carried out. If the perforation diameter is too large, it should be straightened and corrected. After straightening, it is transferred to the flaw detector by the conveyor for flaw detection test, and finally placed in the warehouse after labeling and specification arrangement.

Process flow chart of cold-drawn seamless carbon steel pipe

Cold-drawn seamless carbon steel pipe process.
Round tube billet → heating → perforation → head → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → blank tube → heat treatment → straightening → Hydraulic test (inspection) → mark → storage.

In a General cold-rolled strip machine, the volume should be continuously annealed (CAPL unit) to eliminate cold quenching and rolling stress, or batch annealing to achieve the mechanical properties specified in the corresponding standards. The surface quality, appearance, and dimensional accuracy of cold-rolled steel sheets are better than that of hot-rolled steel sheets, and the thickness of the product is about 0.18mm for rolling thin, so it is favored by the majority of users.

The cold-drawn steel pipe is made of hot-rolled steel coil as raw material, it’s subjected to pickling to remove scale and then cold-rolled. The finished product is rolled hard roll. The cold work hardening is caused by continuous cold deformation to make the strength and hardness of the rolled hard roll rise and tough. The plastic index is reduced, so the stamping performance will deteriorate and can only be used for parts that are simply deformed.

Process flow chart of hot rolled seamless carbon steel pipes

The raw material for rolling seamless tubes is round tubes, and the tube embryos are cut to raw lengths of about 1 meter by a cutting machine and heated by a conveyor belt to the furnace.
Hot-rolled (extruded seamless steel pipe)

Round tube billet → heating → perforation → three-roll cross-rolling, continuous rolling or extrusion → pipe removal → sizing (or reducing diameter) → cooling → blank tube → straightening → water pressure Test (or flaw detection) → mark → into storage.
The billet is fed into a heating furnace at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene. The control of the furnace temperature is crucial to grind the round air ducts and release the pressure after the punch. One of the taper roller punches is generally higher than the ordinary taper roller punch this kind of punch, has high production efficiency, good product quality, large perforation expansion, and wear-resistant various steel. After perforation, the round pipe is cross-rolled, rolled, or extruded by three rollers.
After extruding the pipe size. The sizing machine through the high-speed rotation of the conical drill into the billet punch to form a steel pipe. The inner diameter of the steel pipe is determined by the length of the outer diameter of the sizer bit. After sizing, the steel pipe enters the cooling tower to be cooled by water spray. After the steel pipe is cooled, it needs to be straightened. Sent by the delivery tube through the straightening of the metal flaw detection machine (or hydraulic test) for internal flaw detection. Will detect cracks, bubbles, and other problems inside the steel pipe.

The process flow of a hot rolled seamless carbon steel pipe production base can be summarized in three stages: perforation, extension, and finishing.
The main purpose of the perforation process is to become a solid round billet perforated with a hollow shell. The capillary tube does not meet the requirements of the finished product in terms of specification, precision, and surface quality, and further improvement is required to get the metal through the deformation. The main purpose of the drawing machine is to further reduce the cross-sectional figure (main compression wall) to obtain a greater axial extension, thus improving the dimensional accuracy, surface quality, and organizational properties of the capillary pipe.

Steel pipe quality inspection will also be done by strict hand selection. The quality of steel pipe is monitored and inspected using the number, size, and production lot of spray paint. A cable car hanging in the warehouse.

How to make welded carbon steel pipes & tubes?

Yaang produces a wide range of welded steel pipes, including ERW, HFI, EFW, LSAW, DSAW, and UOE-type carbon steel pipes and their respective flanges and fittings.
Welded steel pipe manufacturing process is simple and efficient, with many varieties, different specifications, less equipment, and less capital, but the total strength is not as good as a seamless steel pipe. since the 1930s, with the rolling production of high-quality strip steel and the rapid development of welding detection technology, the quality of the weld seam continues to improve, and the specifications of welded steel pipe are increasing, replacing non-pipe joints in more and more areas.
Pipes can be divided into two types according to the basic shape of the longitudinal weld seam, and spiral welded pipe.

Longitudinal welded pipe has the advantages of simple production process, high production efficiency, low cost and rapid development. The strength of spiral welded pipe is generally higher than that of straight seam welded pipe. It can produce welded pipe with larger pipe diameter with narrow blank, and it can also produce welded pipe with different pipe diameters with blank of the same width. However, compared with the straight seam pipe with the same length, the weld length increases by 30-100%, and the production speed is low.
Welded pipes with large or thick diameter are usually made of steel blanks directly, while small welded pipes and thin-walled welded pipes only need to be welded directly through steel strips. Then after simple polishing, wire drawing is OK. Therefore, straight seam welding is mostly used for small-diameter welded pipes, while spiral welding is mostly used for large-diameter welded pipes.

(1). LSAW pipe (Longitudinal Submerged Arc-Welding Pipe), also called SAWL pipe.

LSAW pipe is generally made of steel plate through different forming processes, including double-sided submerged arc welding and post weld expanding.

Forming technology of longitudinal submerged arc welded pipe

Description of main production process of large diameter longitudinal welded pipe:

• 1. Plate detection: after the steel plate used to manufacture large-diameter submerged arc welded straight seam steel pipe enters the production line, first conduct full plate ultrasonic inspection;
• 2. Edge milling: the two edges of the steel plate are milled on both sides by the edge milling machine to achieve the required plate width, plate edge parallelism and groove shape;
• 3. Pre bending: use the pre bending machine to pre bend the plate edge, so that the plate edge has the required curvature;
• 4. Forming: on the JCO forming machine, first press half of the pre bent steel plate into a “J” shape through multiple step stamping, then bend the other half of the steel plate into a “C” shape, and finally form an open “O” shape
• 5. Pre welding: make the formed straight seam welded steel pipe joint and use gas shielded welding (MAG) for continuous welding;
• 6. Internal welding: longitudinal multi wire submerged arc welding (up to four wires) is used to weld inside the straight seam steel pipe;
• 7. External welding: longitudinal multi wire submerged arc welding is used to weld the outside of the longitudinal submerged arc welded steel pipe;
• 8. Ultrasonic inspection I: 100% of the internal and external welds of the straight welded steel pipe and the base metal on both sides of the weld;
• 9. X-ray inspection I: 100% X-ray industrial television inspection shall be carried out for internal and external welds, and image processing system shall be adopted to ensure the sensitivity of flaw detection;
• 10. Diameter expansion: expand the full length of submerged arc welded straight seam steel pipe to improve the dimensional accuracy of steel pipe and improve the distribution of internal stress in steel pipe;
• 11. Hydrostatic test: inspect the expanded steel pipes one by one on the hydrostatic test machine to ensure that the steel pipes meet the test pressure required by the standard. The machine has the function of automatic recording and storage;
• 12. Chamfering: process the pipe end of the qualified steel pipe to meet the required groove size of the pipe end;
• 13. Ultrasonic inspection II: carry out ultrasonic inspection one by one again to check the possible defects of longitudinal welded steel pipes after diameter expansion and water pressure;
• 14. X-ray inspection II: X-ray industrial television inspection and pipe end weld photography shall be carried out for steel pipes after diameter expansion and hydrostatic test;
• 15. Magnetic particle inspection of pipe end: conduct this inspection to find pipe end defects;
• 16. Corrosion prevention and coating: the qualified steel pipe shall be subject to corrosion prevention and coating according to the user’s requirements.

The main equipment includes edge milling machine, pre bending machine, forming machine, pre welding machine, expanding machine, etc. At the same time, the forming methods of longitudinal submerged arc welded pipes include UO (UOE), Rb (RBE), JCO (JCOE), etc. The steel plate is first pressed into a U shape in the forming mold, then into an O shape, and then the internal and external submerged arc welding is carried out. After welding, the expanding at the end or the full length is usually called UOE welded pipe, and the non expanding is called UO welded pipe. Roll bending the steel plate, and then conduct internal and external submerged arc welding. After welding, the expanded diameter is RBE welded pipe or RB welded pipe without expanding diameter. Shape the steel plate in the order of j-type-c-type-o, and expand the diameter to JCOE welded pipe or JCO welded pipe without diameter expansion after welding
UOE longitudinal submerged arc welded pipe forming process:
The three main forming processes of UOE longitudinal submerged arc welded steel pipe forming process include: steel plate pre bending, u forming and O forming. Each process adopts a special forming press to complete the three processes of steel plate edge pre bending, u forming and O forming in turn, so as to deform the steel plate into a circular tube.
JCOE longitudinal submerged arc welded pipe forming process:
Forming: after multiple step stamping on the jc0 forming machine, first press half of the steel plate into “J”, “shape, then press the other half of the steel plate into” J “shape to form a” C “shape, and finally press from the middle to form an open” 0 “shape tube blank. As shown in the figure:
Comparison of JCO and UO molding methods:
JCO molding is progressive pressure molding, which changes the molding process of steel pipe from two steps of UO molding to multiple steps. During the forming process, the steel plate deforms evenly, the residual stress is small, and the surface is not scratched. The processed steel pipe has greater flexibility in the size range of diameter and wall thickness, which can produce both large quantities of products and small batches of products; It can produce both large-diameter high-strength thick wall steel pipes and small-diameter large wall steel pipes; In particular, it has incomparable advantages in the production of high-grade thick wall tubes, especially small and medium-sized thick wall tubes. It can meet more requirements of users in terms of steel pipe specifications. The investment is small, but the production efficiency is low. Generally, the annual output is 100000-250000 tons.
UO molding, using u and o two pressure molding, is characterized by large capacity and high output. Generally, the annual output can reach 300000-1000000 tons, which is suitable for mass production of a single specification. The investment is too large for the average developing country to bear.

(2). Spiral welded steel pipe

Longitudinal strength is generally higher than this, can be narrower diameter billet production, but also use the same width of the billet production of different diameter welded pipe; but compared with the same length of straight seam pipe, spiral welded steel pipe weld length of 30%-100%, and lower productivity; therefore, smaller diameter pipes actually use straight seam welding, large diameter spiral welded pipe is mostly used.

Production process of spiral steel pipe

Spiral steel pipe is a kind of spiral seam steel pipe, which is made of strip steel coil, often formed by warm extrusion and welded by automatic double wire double-sided submerged arc welding process

• (1) Raw materials, i.e. strip steel coil, welding wire and flux. Strict physical and chemical tests should be carried out before investment.
• (2) The butt joint of strip steel head and tail adopts single wire or double wire submerged arc welding, and automatic submerged arc welding repair welding is adopted after rolling into steel pipe.
• (3) Before forming, the strip steel is leveled, trimmed, planed, cleaned, transported and pre bent.
• (4) The electric contact pressure gauge is used to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth transportation of strip steel.
• (5) Adopt external control or internal control roll forming.
• (6) The weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, unfitness and weld gap are strictly controlled.
• (7) Both internal welding and external welding adopt American Lincoln Electric welding machine for single wire or double wire submerged arc welding, so as to obtain stable welding quality.
• (8) All welded welds are inspected by online continuous ultrasonic automatic flaw detector, ensuring 100% coverage of nondestructive testing of spiral welds. If there is a defect, it will automatically alarm and spray marks, and the production workers will adjust the process parameters at any time to eliminate the defect in time.
• (9) The steel pipe is cut into single pieces by air plasma cutting machine.
• (10) After cutting into a single steel pipe, each batch of steel pipes shall be subject to a strict first inspection system to check the mechanical properties, chemical composition, fusion condition of the weld, the surface quality of the steel pipe and the non-destructive inspection to ensure that the pipe manufacturing process is qualified before it can be officially put into production.
• (11) The parts with continuous acoustic flaw detection marks on the weld shall be rechecked by manual ultrasonic and X-ray. If there are defects, they shall be repaired and then undergo nondestructive inspection again until it is confirmed that the defects have been eliminated.
• (12) The butt weld of strip steel and the pipe where the T-joint intersects with the spiral weld have all been inspected by X-ray television or film.
• (13) Each steel pipe is subject to hydrostatic test, and the pressure adopts radial seal. The test pressure and time are strictly controlled by the microcomputer detection device of steel pipe water pressure. Test parameters are automatically printed and recorded.
• (14) The pipe end is machined so that the perpendicularity, slope angle and blunt edge of the end face can be accurately controlled.

(3). ERW straight seam welded pipe

ERW straight seam welded pipe, also known as “resistance welded straight seam welded pipe”, ERW straight seam welded pipe is mainly divided into ERW AC welded pipe and ERW DC welded pipe. ERW longitudinal welded pipe is further divided into low-frequency welding, medium frequency welding, ultra medium frequency welding and high-frequency welding according to different frequencies.

Production process of straight seam high-frequency welded pipe

(4). Straight seam high-frequency welded pipe

Straight seam high-frequency welded pipe (ERW) is produced by heating and melting the edge of the pipe blank by using the skin effect and proximity effect of high-frequency current after the hot-rolled coil is formed by the forming machine, and pressure welding is carried out under the action of the extrusion roll.

High frequency welding is mainly used to produce thin-walled steel pipes or ordinary thick walled steel pipes. High frequency welding is divided into contact welding and induction welding.
The straight seam high-frequency welded steel pipe has advanced forming technology, reliable quality, good welding position, stable welding parameters, fast welding speed and high output. The equipment and technology of the whole production line are currently at the world-class level.
Characteristic:

• (1) The forming process of straight seam high-frequency welded steel pipe has small springback and residual stress.
• (2) The deformation hardening effect is small, and the geometric dimension after the fillet is accurate, which is conducive to ensuring the construction and welding quality.
• (3) The weld shape of high-frequency welded straight seam steel pipe is good, not easy to undercut, and the internal and external welding of medium defects is incorrect.
• (4) The weld of straight seam steel pipe is distributed at a point on the circumference. Therefore, the weld can be placed in a favorable position according to the use requirements.

It is mainly used for the transportation of onshore and offshore oil and gas, coal slurry, mineral slurry and other media, as well as the transportation of offshore platforms, power stations, chemical industry, urban buildings and other pipelines.

Production process of straight seam high-frequency welded pipe

According to different high-frequency welding processes, high-frequency straight seam welded steel pipes can be divided into straight seam high-frequency resistance welded steel pipes and straight seam high-frequency induction welded steel pipes. Roll bending cold forming is generally used as the forming process.
High frequency straight seam welded steel pipes are generally produced with smaller diameters, generally with an outer diameter of 660mm or less than 26 inches. It is characterized by high welding speed. For example, for steel pipes with an outer diameter of less than 1 inch, the maximum welding speed can reach 200 meters / minute. For steel pipes with an outer diameter of 25 inches, the welding speed can also reach more than 20 meters / minute. Its welding is crimping rather than fusion welding. Compared with fusion welding, the welding heat affected zone is relatively small and has little impact on the structure of the base metal. The strength and toughness of the weld after welding are different from that of the parent. According to the use requirements, the internal and external welding burrs can be cleaned or not. Welding can not clean the workpiece, but can weld thin-walled pipes and metal pipes.
High frequency straight seam welded steel pipe process: longitudinal shearing uncoiling strip steel leveling head and tail shearing strip steel butt welding looper stock forming welding deburring sizing flaw detection flying cutting initial inspection steel pipe straightening pipe section processing hydrostatic test flaw detection printing and coating finished products. High frequency straight seam welded steel pipes are mainly used in tap water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation and urban construction.

Pipeline use is divided into the following categories.

• (1) General welded steel pipe: welded steel pipe for the transport of general low-pressure fluids. Contains Q195A, Q215A, and Q235A steel. Can be easily applied to other soft steel welded steel pipe pressure, bending, flattening, and other experiments, here there are certain surface quality requirements, the delivery length is usually 4-10m, often required to cut to a certain length (or double length) delivery s specifications and nominal pipe diameter indicated (mm or inches) the difference between the nominal diameter and the actual diameter of the pipe required thick-walled ordinary steel and steel pipe is two kinds of steel, according to the form of pipe Divided into two types with threaded ends and non-threaded ends.
• (2) Galvanized welded steel pipe: To improve the corrosion resistance of steel pipe, general steel pipe (single reed pipe) for galvanized steel and electrical steel, hot dipped galvanized zinc there are two kinds of galvanized thickness, galvanized low cost.
• (3) Oxygen welded steel pipe: piping for steelmaking oxygen, usually with small diameter welded steel pipe, size from 3/8 inch to 2 inches 8. made of 08, 10, 15, 20 or Q195-Q235 steel strip corrosion, for partial aluminizing treatment.
• (4) Line pipe: welded steel pipe is also common carbon steel, concrete, and various distribution engineering structures used in steel pipe, commonly used nominal diameter of 13-76mm.
• (5) Metric welded steel pipe: seamless form, specifications expressed in millimeters diameter * wall thickness of welded steel pipe, with ordinary carbon steel, high carbon steel or low alloy steel and P welding to tropical and cold regions, or welded with tropical methods to call cold regions. Metric and thin-walled tube points are commonly used in structural parts, such as shafts or transmission fluid, for the production of thin-walled furniture, lamps, etc., to ensure the strength of steel and bending tests.
• (6) Roller: roller conveyor with welded steel pipe, generally 304/304L, 316/316L, 2205, 2507, Q215, Q235A, 45# steel, B steel, and 20# steel, diameter 63.5-219.0mm. bending of the tube, the end is perpendicular to the center line, ellipticity has certain requirements, general test pressure, and flatness.

Difference between longitudinal welded pipe and spiral welded pipe

Both longitudinal welded pipe and spiral welded pipe are a kind of welded steel pipe, which are widely used in national production and construction. Longitudinal welded pipe and spiral welded pipe have many differences due to different production processes. The differences between longitudinal welded pipe and spiral welded pipe are discussed in detail below. The production process of straight seam welded pipe is relatively simple. The main production processes include high-frequency welded straight seam welded pipe and submerged arc welded straight seam welded pipe. Straight seam welded pipe has high production efficiency, low cost and rapid development. The strength of spiral welded pipe is generally higher than that of straight seam welded pipe. The main production process is submerged arc welding. Spiral welded pipe can produce welded pipes with different pipe diameters with blanks of the same width, and it can also produce welded pipes with larger pipe diameters with narrow blanks. However, compared with the straight welded pipe with the same length, the weld length increases by 30-100%, and the production speed is low. Therefore, straight seam welding is mostly used for small-diameter welded pipes, while spiral welding is mostly used for large-diameter welded pipes. When producing large-diameter straight seam welded pipes in the industry, T-shaped welding technology will be used, that is, short straight seam welded pipes will be butt welded and connected to a length that meets the needs of the project. The probability of defects of T-shaped straight seam welded pipes will also be greatly improved. Moreover, the welding residual stress at the T-shaped weld is relatively large, and the weld metal is often in a three-dimensional stress state, increasing the possibility of cracks.

• 1. In terms of welding process: the welding methods of spiral welded pipe and straight seam welded pipe are the same. The straight seam steel pipe will inevitably have a lot of T-shaped welds, so the probability of welding defects will be greatly improved. Moreover, the welding residual stress at the T-shaped welds is large, and the weld metal is often in the state of three-dimensional stress, increasing the possibility of cracks. Moreover, according to the process regulations of submerged arc welding, each weld should have an arc striking place and an arc extinguishing place, but each straight seam welded pipe cannot meet this condition when welding the circumferential seam, so there may be more welding defects at the arc extinguishing place.
• 2. When the pipe is under internal pressure, there are usually two main stresses on the pipe wall, namely radial stress δ And axial stress δ。 Resultant stress at weld δ， Among them, the spiral angle of the weld.
• 3. The spiral steel pipe weld is a spiral angle, so the synthetic stress at the spiral weld is the main stress. Under the same working pressure, the wall thickness of spiral steel pipe with the same diameter can be reduced compared with that of straight welded pipe. According to the above characteristics, when the spiral steel pipe explodes, because the normal stress and synthetic stress on the weld are relatively small, the blast hole generally does not originate from the spiral weld, and its safety is higher than that of the straight seam welded pipe. When there are parallel defects near the spiral weld, the risk of expansion of the spiral weld is less than that of the straight weld because the stress on the spiral weld is small. Since the radial stress is the maximum stress existing on the steel pipe, the weld will bear the maximum load when it is in the direction of vertical stress. That is, the load borne by the straight seam is the largest, the load borne by the circumferential weld is the smallest, and the spiral seam is between the two.
• 4. Static bursting strength: through relevant comparative tests, it is verified that the yield pressure of spiral steel pipe and longitudinal welded pipe is basically consistent with the measured and theoretical value of bursting pressure, and the deviation is close. However, whether it is yield pressure or burst pressure, spiral steel pipe is lower than straight seam welded pipe. The burst test also showed that the circumferential deformation rate of the burst port of the spiral steel pipe was significantly higher than that of the straight seam welded pipe. It is proved that the plastic deformation capacity of spiral steel pipe is better than that of straight seam welded pipe, and the blast hole is generally limited to one pitch, which is caused by the strong restraint effect of spiral weld on the expansion of the crack.
• 5. Toughness and fatigue strength: the trend of pipeline development is large diameter and high strength. With the increase of steel pipe diameter and the improvement of steel grade, the trend of ductile fracture tip stable propagation is greater. According to the tests of relevant research institutions in the United States, although the spiral steel pipe and the longitudinal welded pipe are at the same level, the spiral steel pipe has high impact toughness.
• 6. Due to the change of transmission capacity of the transmission pipeline: in the actual operation process, the steel pipe is subjected to random alternating load. Understanding the low cycle fatigue strength of steel pipes is of great significance to judge the service life of pipelines.
• 7. According to the measurement results, the fatigue strength of spiral steel pipe is the same as that of seamless pipe and resistance welded pipe, and the test data are distributed in the same area as that of seamless pipe and resistance pipe, which is higher than that of general submerged arc straight seam welded pipe.

Dimensional tolerance of ERW steel pipe

Tolerance of outside diameter

Out Diameter	Tolerance of Pipe End	Tolerance of Pipe Body
219.1-273.1	+1.6mm, -0.4mm	±0.75%
274.0-320	+2.4mm, -0.8mm	±0.75%
323.9-457	+2.4mm, -0.8mm	±0.75%
508	+2.4mm, -0.8mm	±0.75%
559-610	+2.4mm, -0.8mm	±0.75%

Tolerance of wall thickness

Grade	Out Diameter	Wall Thickness
/	219.1-457	+15%, -12.5%
B	508-610	+17.5%, -12.5%
X42-X80	508-610	+19.5%, -8%

Ends of carbon steel pipe

For the ends of pipes are 3 standard versions available.

• Plain Ends (PE)
• Threaded Ends (TE)
• Beveled Ends (BE)

The TE implementation speaks for itself, this performance will generally be used for small diameter piping systems, and the connections will be made with threaded flanges and threaded pipe fittings.

The BE implementation is applied to all diameters of buttweld flanges or buttweld pipe fittings and will be directly welded (with a small gap of 3-4 mm) to each other or to the pipe.

Ends are mostly beveled to the angle of 30° (+ 5° / -0°) with a root face of 1.6 mm (± 0.8 mm).

Length of carbon steel pipe

Piping lengths from the factory are not exactly cut to length but are normally delivered as:

• The single random length has a length of around 5-7 meter
• The double random length has a length of around 11-13 meter
• Shorter and longer lengths are available, but for calculation, it is wise, to use this standard length;
• other sizes are probably more expensive.

Inspection Quality of carbon steel pipe

Our factory is ISO 9001 and CE-PED approved manufacturer. We believe that quality is the life of the company. To provide quality products is the thing we are doing.

• PMI test to ensure the material quality;
• Dimension controlling during fabricating and finishing;
• 100% Visual and surface examination;
• NDT test (Eddy Current and Hydro Test);
• Another requirement on request.

Eddy Current Test	Hydrostatic Test	Radiography Test (for welded pipe)	Liquid Dye Penetrant Test
Bending Test	Ultrasonic Test	Tensile Test	Flaring Test
Flattening Test	Hardness Test	Positive Material Identification (PMI)	Surface Roughness
Hardness Test	Dimension Examination	Visual Checking	Impact Test
Intergranular Corrosion Test	Grain Size Test	Chemical Analysis	Other tests on the requirement

Acceptance of steel pipes

The acceptance of the steel pipe is mainly divided into the following contents:
Size

• A. Nominal size: It is the nominal size specified in the standard, which is the ideal size that users and manufacturers hope to get, and also the order size specified in the contract.
• B. Actual size: It is the actual size obtained in the production process, which is often larger or smaller than the nominal size. This phenomenon of larger or smaller than the nominal size is called deviation.
• C. Meter weight: weight per meter = 0.02466*wall thickness * (outside diameter – wall thickness)

Deviation and tolerance

• A. Deviation: In the production process, because the actual size is difficult to meet the nominal size requirements, that is, often larger or smaller than the nominal size, so the standard provides for a difference between the actual size and the nominal size is allowed. The difference is called positive deviation, the difference is called negative deviation.
• B. Tolerance: The sum of the absolute values of positive and negative deviation values specified in the standard is called tolerance, also called “tolerance zone”.

Deviation is directional, that is, “positive” or “negative”; tolerance is not directional, therefore, the deviation value called “positive tolerance” or “negative tolerance” is wrong.
Delivery length
The delivery length is also called the user requirement length or contract length. The standard delivery length has the following provisions.
A. The usual length (also known as non-fixed length): where the length of the standard length range and no fixed length requirements, are called the usual length. For example, structural pipe standards: hot-rolled (extruded, expanded) steel pipe 3000mm – 12000mm; cold-drawn (rolled) steel pipe 2000mm ~ 10500mm.
B. Cut-to-length: cut-to-length should be within the usual length range, a certain fixed length size required in the contract. But in practice are cut out of the absolute length of the fixed length is unlikely, so the standard for the length of the fixed length of the allowed positive deviation value.
Take the standard of structural pipe as: production of fixed-length pipe than the usual length of the pipe into a larger rate of decline, the production enterprises to raise the price request is reasonable. The price increase is not consistent among enterprises, generally about 10% on the basis of the base price.
C. Times the length: times the length should be within the usual length, the contract should specify the single times the length and the total length of the multiples (for example, 3000mm × 3, that is, 3 times the number of 3000mm, the total length of 9000mm). In practice, the total length should be added to the allowable positive deviation of 20mm, plus each single times the length of the length should be left with a margin of cut. Take the structural tube as an example, it is stipulated to leave a margin of notch: 5~10mm for OD≤159mm; 10~15mm for OD>159mm.
If the standard does not have the deviation of the length and cutting allowance, the supply and demand sides should negotiate and specify in the contract. Double length with the same fixed length, will bring to the production enterprises into the material rate significantly reduced, so the production enterprises to raise the price is reasonable, the rate of increase with the fixed length rate of increase is basically the same.
D. Range length: range length in the usual length range, when the user requires a fixed range length, need to be specified in the contract.
For example: the usual length is 3000-12000mm, while the range of fixed length is 6000-8000mm or 8000-10000mm.
It can be seen that the range length is more lenient than the fixed length and times the length requirements, but much stricter than the usual length, but also to the production enterprises will bring the reduction of the material rate. Therefore, it is reasonable for the production enterprises to propose a price increase, and its price increase is generally about 4% on the base price.
Uneven wall thickness
The wall thickness of steel pipe cannot be the same everywhere, and there are objective wall thickness inequalities in its cross-section and longitudinal body, i.e. uneven wall thickness. In order to control this unevenness, there are steel pipe standards in the wall thickness unevenness of the allowable indicators, generally not more than 80% of the wall thickness tolerance (after consultation between the supply and demand for implementation).
Ellipticity
In the cross-section of the round steel pipe there is the phenomenon of unequal outside diameter, that is, there is not necessarily perpendicular to each other, the maximum outside diameter and the minimum outside diameter of the difference between the maximum outside diameter and the minimum outside diameter is the ellipticity (or not roundness). In order to control the ellipticity, some steel pipe standards specify the allowable index of ellipticity, generally specified as not more than 80% of the outside diameter tolerance (after consultation between the supply and demand for implementation).
Curvature
Steel pipe is curved in the direction of length, the curvature is expressed in figures called bend. The standard bending degree is generally divided into the following two kinds.
A. Local curvature: a meter-long straightedge against the maximum bend in the steel pipe, measured its chord height (mm), that is, the value of local curvature, the unit is mm / m, such as 2.5mm / m. This method is also applicable to the pipe end curvature.
B. The total length of the curvature: a thin rope, from the ends of the tube tension, measuring the maximum chord height at the bend of the steel pipe (mm), and then converted into a length (in meters) of the percentage, that is, the length of the steel pipe direction of the full-length curvature.

For example: the length of the steel pipe is 8m, measured the maximum chord height of 30mm, the tube should be the full-length bend: 0.03 ÷ 8m × 100% = 0.375%

End face: both ends of the steel pipe should be burr-free, chamfering should be R angle.
Surface: The outer surface of the product should not have pitting, bulging corrosion and other defects; otherwise it will affect the service life of the steel pipe (for example, if there is pitting on the inner surface of the steel pipe connected to the oilfield equipment, it will lead to leakage when pressure is applied during the operation).
Straightness of steel pipe
Straightness is the measurement of the deviation of the longitudinal axis of a pipe from a straight line. Straightness is measured by the ratio of the difference between the straightness of the pipe and its reference length.
The straightness requirements for steel pipe can be divided into three classes.

• Class I – Straightness is specified to be less than 0.02%. This level is typically required for large diameter pipelines used in high pressure and high temperature applications such as oil, gas, water and steam pipelines; also for marine applications such as mooring and anchor chains; offshore structures such as wind turbines, subsea risers ; nuclear power plants, etc.
• Class II – Straightness is specified as less than 0.08%. This level may be required for medium-sized pipelines used at low pressures (e.g., air conditioning systems or refrigeration systems); smaller diameter gas transmission pipelines that are not subject to severe bending forces but require a minimum bend radius for ease of installation, e.g., residential gas transmission pipelines that require small bends for installation in buildings; medium-sized pole and tower sections, etc., where there are no special requirements for wall thickness or minimum bend neck and therefore cannot use manual straightening machines (SMT) and other conventional methods to meet tighter tolerances.

Eccentricity of Steel Tubes
The eccentricity of a steel pipe is the difference between its shortest and longest diameters. The eccentricity of a tube should be less than 0.5 mm, but is usually measured with a concentricity gauge. It is an important parameter of steel pipe because it affects the weldability and mechanical properties of the finished pipe system.

Tolerance standard of steel pipe

Allowable deviation of outer diameter

     Allowable deviation of standardized outer diameter

Deviation grade	Allowable deviation of standardized outer diameter
D1	± 1.5%, min. ± 0.75 mm
D2	±1.0%, Minimum ± 0.50 mm
D3	± 0.75%, min ± 0.30 mm
D4	±0.50%, Minimum ± 0.10 mm
Allowable deviation of non standardized outer diameter
Deviation grade	Allowable deviation of non standardized outer diameter,%
ND1	+1.25
	-1.50
ND2	±1.25
ND3	+1.25
	-1.O
ND4	±0.8

The allowable deviation of the outer diameter of steel pipes for special purposes and cold rolled (drawn) steel pipes can adopt absolute deviation.
The allowable deviation of wall thickness can be divided into standardized and non standardized. The standardized allowable deviation of wall thickness should be preferred.
Allowable deviation of wall thickness

Deviation grade		Allowable deviation of wall thickness
		S/D
		0.1< S／D	O.05<S／D≤0.1		0.025<S／D≤0.05		S/D≤0.025
S1		±15%, minimum ±0.6 mm
S2	A	±12.5%, minimum ±0.4 mm
	B	+Positive deviation depends on weight requirements
		-12.5
S3	A	±10%, minimum ±0.2mm
	B	±10%		±12.5%		±15%
		minimum ±0.4mm
	C	+Positive deviation depends on weight requirements
		-12.5
S4	A	±7.5%,  minimum ±0.15 mm
	B	±7.5%	±10%		±12.5%		±15%
		minimum 士0.2 mm
S5		±5%，minimum 士0.10 mm
Note: S is the nominal wall thickness of steel pipe, and D is the nominal outer diameter of steel pipe.

Allowable deviation of recommended non standardized wall thickness

Deviation grade	Allowable deviation of non standardized wall thickness，%
NSl	15
	-12.5
NS2	15
	-10
NS3	+12.5
	-10
NS4	-12.5
	-7.5

The allowable deviation of wall thickness of steel pipes for special purposes and cold rolled (drawn) steel pipes can be absolute.
Length
General length:
Steel pipes are generally delivered in the usual length. Generally, the length shall meet the following requirements:

• Hot rolled (expanded) pipe: 3000-12000 mm;

• Cold rolled (drawn) pipe: 2000-10500 mm.

The length of hot-rolled (expanded) short tube shall not be less than 2 m. The length of cold-rolled (drawn) short tube shall not be less than 1 m.
Fixed length and double length:
The fixed length and double length shall be within the normal length range. The allowable deviation of the full length is divided into three levels Cut allowance shall be reserved for each multiple length according to the following provisions:

• Outer diameter ≤ 159 mm:5 – 10 mm;

• Outer diameter >159 mm: 10 – 15 mm.

Allowable deviation of total length

Allowable deviation grade of full length	Allowable deviation of total length.mrn
Ll	0-20
L2	0-10
L3	O-j

Steel pipes for special purposes
For example, the length requirements of stainless acid resistant steel, extremely thin-walled steel pipes, small-diameter steel pipes, etc. can be specified separately.

Packing of carbon steel pipe

• Packed in wooden crates, wrapped in plastic, and suitably protected for sea-worthy delivery or as requested.
• Both ends of each crate will indicate the order no., heat no., dimensions, weight, and bundles or as requested.

Delivery of carbon steel pipe

• Pipes are supplied in hexagonal bundles or round bundles tied with steel strips.
• Weight of bundle – up to 5000 kg upon request of the customer.
• Each bundle is furnished with three tags.

Alloy steel pipe is a type of metal material that has many different uses and applications. It is important to know how to choose the right carbon steel pipe for your project, so we have outlined some tips below on how to do this effectively.

Repair and maintenance of carbon steel pipes

Regular repair and maintenance of carbon steel pipes are crucial to prolong their service life, maintain their performance, and prevent failures or accidents. Some common repair and maintenance practices for carbon steel pipes include:
Leak detection and repair
Regularly inspect the piping system for leaks, using methods such as visual inspection, ultrasonic testing, or pressure testing. Promptly repair any detected leaks to prevent further damage, contamination, or loss of fluids or gases.
Corrosion monitoring and control
Monitor the pipes for signs of corrosion, such as discoloration, pitting, or surface irregularities. Implement corrosion control measures, such as periodic cleaning, application of corrosion inhibitors, or cathodic protection, to mitigate corrosion and prolong the pipe’s service life.
Coating and lining maintenance
Inspect the pipe’s coatings and linings for signs of damage or wear, such as cracks, peeling, or blistering. Repair or replace damaged coatings or linings to maintain the pipe’s corrosion resistance and structural integrity.
Pipe support inspection and adjustment
Regularly inspect the pipe supports for signs of wear, corrosion, or deformation. Adjust or replace worn or damaged supports to maintain proper alignment and prevent excessive stress on the pipes.
Replacement of worn or damaged components
Periodically inspect the piping system’s components, such as fittings, valves, and flanges, for signs of wear, damage, or corrosion. Replace worn or damaged components to maintain the system’s performance and prevent failures or accidents.

Decommissioning and recycling of carbon steel pipes

At the end of their service life, carbon steel pipes may need to be decommissioned and disposed of or recycled. Some steps to consider during the decommissioning and recycling process include:
Removal and disassembly
Safely remove and disassemble the piping system, taking care to prevent damage to the surrounding environment or infrastructure. Properly dispose of any hazardous materials, such as contaminated fluids or gases, according to local regulations and guidelines.
Material separation
Separate the various materials in the piping system, such as steel, coatings, linings, and fittings, to facilitate recycling or disposal. Some materials, such as polyethylene coatings or cement mortar linings, may need to be removed or treated before recycling.
Recycling and waste management
Recycle the carbon steel pipes and other recyclable materials, such as fittings, flanges, or supports, according to local recycling programs and facilities. Properly dispose of any non-recyclable materials or waste, adhering to local waste management regulations and guidelines.
By implementing a comprehensive approach to the repair, maintenance, decommissioning, and recycling of carbon steel pipes, end-users can optimize the performance and service life of their piping systems while minimizing the environmental impact and overall costs associated with their projects.

Carbon Steel Pipe VS Stainless Steel Pipe

The key differences between carbon and stainless steel pipes include their composition, properties, and applications.

Composition of Carbon Steel Pipe and Stainless Steel Pipe

Carbon Steel Pipe
Carbon steel pipe is made primarily from iron and carbon, with small amounts of other elements like manganese, silicon, and copper. Carbon steel pipe is divided into three main categories: low-carbon steel (also known as mild steel), medium-carbon steel, and high-carbon steel.

• Low Carbon Steel Pipes: These pipes contain 0.05% to 0.30% carbon content and are the most common type of carbon steel pipe. They are easy to form and weld, making them suitable for automobile manufacturing, structural steel, and general-purpose piping applications.
• Medium Carbon Steel Pipes: These pipes have a carbon content ranging from 0.31% to 0.60%. They are stronger than low-carbon steel pipes but less ductile. Medium carbon steel pipes are often used in heavy-duty applications like shafts, gears, and high-pressure pipelines.
• High Carbon Steel Pipes: With a carbon content between 0.61% and 1.50%, high carbon steel pipes are the strongest and hardest among carbon steel pipes. They are used in applications that require high strength and wear resistance, such as drill bits, cutting tools, and high-stress structural components.

Stainless Steel Pipe
Stainless steel pipe is an alloy of steel that contains a minimum of 10.5% chromium, which provides corrosion resistance. There are several types of stainless steel pipes, including austenitic, ferritic, martensitic, and duplex stainless steel pipes.

• Austenitic Stainless Steel Pipes: These pipes contain a higher percentage of chromium (16-26%) and nickel (6-22%), making them the most widely used type of stainless steel pipe. They are non-magnetic, have excellent formability, and are resistant to corrosion. They are commonly used in the food, chemical, and pharmaceutical industries.
• Ferritic Stainless Steel Pipes: These pipes have a lower chromium content (10.5-27%) and little to no nickel. They are magnetic, have moderate corrosion resistance, and are often used in automotive applications, heat exchangers, and architectural elements.
• Martensitic Stainless Steel Pipes: These pipes have a chromium content of 11.5-18% and a higher carbon content (0.15-1.2%). They are magnetic and have good strength and wear resistance. Martensitic stainless steel pipes are commonly used in cutlery, surgical instruments, and fasteners.
• Duplex Stainless Steel Pipes: These pipes have a mixed microstructure of austenitic and ferritic phases, balancing strength, ductility, and corrosion resistance. They are used in chemical processing, oil and gas, and marine applications.

Key Differences between Carbon Steel Pipe and Stainless Steel Pipe

• Corrosion Resistance: Stainless steel pipes have better corrosion resistance than carbon steel pipes due to the presence of chromium. This makes stainless steel pipes more suitable for applications exposed to corrosive environments.
• Strength and Hardness: Carbon steel pipes generally have higher strength and hardness than stainless steel pipes. High-carbon steel pipes, in particular, are known for their exceptional strength.
• Heat Resistance: Stainless steel pipes have better heat resistance than carbon steel pipes. Austenitic stainless steel pipes can maintain their strength and corrosion resistance at high temperatures, making them suitable for heat transfer applications, such as heat exchangers and furnaces.
• Magnetism: Carbon steel pipes are generally magnetic, while austenitic stainless steel pipes are non-magnetic. Ferritic and martensitic stainless steel pipes, however, do exhibit magnetic properties.
• Formability and Weldability: Low carbon steel pipes have excellent formability and weldability, while stainless steel pipes, particularly austenitic stainless steel pipes, exhibit good formability and weldability. On the other hand, high-carbon steel pipes have limited formability and weldability.
• Cost: Carbon steel pipes are generally less expensive than stainless steel pipes due to the higher cost of alloying elements in stainless steel.
• Applications: Carbon steel pipes are commonly used in structural, automotive, and general-purpose applications, while stainless steel pipes are more common in corrosive environments, heat transfer applications, and industries like food processing, chemical processing, and pharmaceuticals.

How to choose carbon steel pipes?

Choosing the type of carbon steel pipe you want to buy is not as easy as it looks. There are many different factors at work, and all these factors should be considered before making a final decision.
The weight of carbon steel pipe must be considered. The weight of carbon steel pipe depends on the thickness and length of the pipe. For example, if you want to ensure that the roof can support the newly installed antenna, you may need to use long tubes to ensure that they do not sag or bend and break under their own weight.
The type of carbon steel pipe is also important.

Understand the types of carbon steel pipes

Carbon steel pipes come in many sizes and shapes. Carbon steel pipes have welded and seamless structures, including flat end (PE), thread (T), flange (f) and inclined end (be). They are also available in a variety of materials, finishes and grades to meet your specific project requirements. The following is a list of some common carbon steel pipe products:

• Type: black and ductile iron;
• Size: 2 ” to 36″ (50mm-900mm) diameter;
• Shape: square / rectangular pipe; Round tube round tube square tube octagonal rectangular hollow section square hollow section rectangular solid hollow section rectangular reticular hollow section tube, etc.

The chemical composition of carbon steel pipes must also be considered

In addition to the chemical composition of carbon steel pipes, the price is also very important. The grade of carbon steel pipe you choose will not only affect the product quality, but also affect the price. For example, if you want to buy high-quality carbon steel pipes with good corrosion resistance and good mechanical properties at a reasonable price, you should choose API 5L PSL-2 standard pipes.

Confirm the size of carbon steel pipe

Check the out of roundness of carbon steel pipe

Out-ofroundness is the difference between the maximum and minimum diameters of the pipe, measured at the same cross section.
In other words, it’s a measurement of any deviation from a perfect circle.
The ovality or eccentricity is a measurement of roundness, taking into account both out-of-roundness and wall thickness variations. It represents the amount of out-of-roundness that could result in a pressure vessel shell under internal pressure.
It can be calculated as:

• Ovality = (maximum diameter – minimum diameter) / maximum diameter

Check the straightness of carbon steel pipe

Straightness is the degree to which a pipe can deviate from a straight line between two points. In addition to factors such as manufacturing quality and handling, straightness can be affected by installation. Straightness can be measured using a straightness meter that measures the difference between the axis of rotation of an object and its geometric centerline.
Wall thickness variation is a measure of how much a pipe’s wall thickness varies across its length and around its circumference.
If the wall thickness has no variation, the pipe will be perfectly round. As an example, if you have a 1-inch-diameter (ID) pipe with an outer diameter (OD) of 1 inch, then its inner diameter (ID) would be 0.75 inches and its inner radius would be 0.625 inches.

Measure the size of carbon steel pipe

Carbon steel pipe is a construction material that is used in home and commercial plumbing systems. The pipe is made of carbon steel and has a specific diameter, weight and wall thickness. The pipe comes in different sizes, which are measured by internal diameter (ID) and external diameter (OD).
The most common usage for carbon steel pipes is to transport water between different parts of your home or building. It can also be used for gas lines as well as compressed air lines. When it comes to sizing this type of piping, it’s important that you get the correct ID and OD measurements so there are no issues once installation takes place.
The best way to measure these dimensions is with a set of calipers or micrometers because they will provide accurate measurements every time you use them! To calculate what size fittings you should use on each end before buying any materials, simply multiply your desired working pressure times two divided by 10 – this will give an approximate size for each end if properly sized fittings were available at all times! For example: If working pressure = 100 PSI x 2 – 200 PSI/ 10 = 20″ = 1″.
The size of carbon steel pipe is important for a variety of reasons, but ultimately it all comes down to ensuring that your system or machine works properly. You should always check the size of your pipe before you buy it, so that you know exactly what you’re getting and can avoid any unwanted surprises later down the road.

Check the price and quality of carbon steel pipes

Once you have determined what type of carbon steel pipe you need, the next step is to determine the price and quality. There are many grades of carbon steel pipes, but there are some basic guidelines that can help you evaluate their quality. The first thing to see is whether they are made of pure steel or alloy steel. Pure carbon steel has less carbon than alloy steel, so it is softer and more ductile. Gases and liquids also pass through it more easily, making it an ideal choice for applications that need to maintain high temperature or pressure in pipes and fittings.
Pure carbon tubes are usually measured according to specification (or thickness). The higher the instrument number on a particular pipe, the thinner the pipe wall than the lower the instrument number, so the cost is lower (but also weaker). For example, the wall thickness of 5/8 inch diameter black iron pipe is about 0.411 inch, while the wall thickness of 1/2 inch diameter M-type copper pipe is about 0.051 inch, which means that its wall thickness is about five times the original!

Packaging and transportation of carbon steel pipes

In order to protect the pipeline from damage during transportation, it must be packaged in a cost-effective, environmentally friendly and safe manner. Some of the most common carbon steel pipe packaging methods are:

• Bundling – this method involves combining several sections of pipes and securing them with wire or cable ties. Then, it can be wrapped with plastic cloth and / or shrink film to fix them together during transportation.
• Wrapping – this method involves wrapping each pipe individually on a spool or spool before packing it into a crate or box.
• Stacking – this method involves stacking individual pipes together and then packaging them in crates or boxes.

When selecting carbon steel pipes, we should consider their quality, purpose and whether they need to be delivered.
You should remember the quality of your pipeline. If you use it for water or natural gas, you may find that you need to meet certain standards. It is important to choose strong materials that are durable and do not corrode over time.
If you purchase carbon steel pipes for commercial use, they may need to meet specifications specific to their use (for example, if there is any galvanizing on them). It is also important to consider which delivery method is most suitable for you when choosing carbon steel pipes. Do you prefer to deliver directly from the manufacturer?

The pipeline used for construction must include anti-corrosion requirements

Carbon steel pipes are widely used in construction engineering. Pipes are usually made of carbon steel and may require corrosion protection. Carbon steel is commonly used in water and wastewater systems, but it is also used in oil pipelines and other industrial applications.
The most common type of pipeline corrosion is intergranular corrosion, which occurs when the layer between particles decomposes over time due to exposure to water or chemicals in the environment. When this happens, small cracks will be formed inside the metal, allowing pollutants such as oxygen or chlorine to enter the water supply system; This may also cause damage to other points in the system, as they must flow through these areas.

The manufacturing process will affect the quality of carbon steel pipes

There are several different methods for manufacturing carbon steel pipes, including:

• Electric arc furnace (EAF)
• Induction melting (IS)
• Oxygen furnace (OF)

The quality of carbon steel pipe depends on how it is made. Each method has its own advantages and disadvantages, as well as its own set of advantages and disadvantages. For example:
Electric arc furnace is one of the most popular methods, because compared with other processes, it is easy to use and cheap; However, if you don’t know what to pay attention to, you may find some defects in your EAF products* Is produces stronger materials than of, but requires more energy than either method.

You must buy certified carbon steel pipes

Needless to say, you should buy a certified carbon steel pipe. This is because certification is the guarantee of quality, safety, durability and reliability. In addition to ensuring sustainable development, it also ensures compliance with all relevant standards, such as ASTM a53/a106/a179 or ASME B36.10M.
If your product has any problems or defects after purchasing from us, please contact us immediately so that we can help you replace or refund after providing the purchase certificate.

Choose a reliable manufacturer or distributor

Before choosing a supplier, please ensure that he or she has a good track record in the industry. When you choose an experienced manufacturer or distributor, you can be sure that your pipeline will meet your needs and provide reliable services for many years. In order to ensure that the company is reputable and experienced, please ask the recommender and thoroughly check it.
Another important factor to consider when choosing a supplier is his or her reputation for high-quality workmanship. In addition to having a long history of providing high-quality products and services, look at other customers in online forums and comment websites (such as yelp!)! Or Angie’s list (for more information about these resources). You should also ask yourself whether the dealer can provide samples so that you can know the manufacturing of its products before you buy products in bulk from him / her / them. This will help prevent any accidents in the future!
A reliable supplier should also provide high-quality customer service: does he / she react quickly when communicating with him / her? Does he / she answer all questions in time? Does anyone in this company know exactly the type of pipe that needs to be replaced? These are just some examples; If something else seems to be wrong when talking to a potential partner, go elsewhere until you find someone who fully meets these three criteria!

Make sure you choose a proven manufacturer

When you choose suppliers, make sure they provide after-sales service. It is very important to choose a supplier with good reputation and customers’ satisfaction with its products and services.
Select suppliers to provide after-sales service
For example, a good supplier will ensure the quality of its products and provide after-sales service. They should provide warranty for their carbon steel pipes to ensure that you get value for money. In addition, they should also provide good customer service so that you can quickly solve any problems.
As you can see, there are many things to consider when choosing carbon steel pipes. If you are looking for a reliable supplier or distributor, we hope these tips can help you search. Please remember that it is important to know the type of material before ordering, and we can help!
When choosing carbon steel pipes, you must consider many things. The weight of carbon steel pipe must be considered. The type of carbon steel pipe is also important, and its chemical composition must also be considered. You need to buy certified carbon steel pipes, because the manufacturing process may affect the quality of this material.

For free carbon steel pipe solutions, please contact us.

Source: China Piping Solutions Provider – Yaang Pipe Industry Co., Limited (www.epowermetals.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, and Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels, and other industries.)

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