GB/T 8163-2008 Fluid Transport Seamless Steel Pipe

GB/T 8163-2008 fluid transport seamless steel pipes are commonly used in various industries, including structure steel, fluid pipe, boiler pipe, gas pipe, and oil pipe.

GB 8163 steel pipes, compliant with the Chinese national standard GB/T 8163-2018, are seamless carbon steel pipes designed for fluid transportation pipes, suitable for conveying water, oil, gas, and other fluids. These pipes are widely used in industries such as petroleum, natural gas, chemical engineering, and power generation due to their high strength, durability, and smooth internal surfaces.

Manufactured through hot-rolling or cold-drawing processes, GB/T 8163 seamless pipes are available in outer diameters from 21.3 mm to 914 mm and wall thicknesses from 2 mm to 60 mm, as per GB/T 17395. Common steel grades include 10#, 20#, Q345B, and 27SiMn, with 20# and Q345B being popular for their balance of mechanical properties and cost-effectiveness. These pipes are designed to withstand various temperatures and pressures, making them ideal for fluid transportation applications.

GB 8163 steel pipes undergo rigorous testing, including tensile, impact, flattening, and hydrostatic tests, to ensure compliance with GB/T 8163-2018 standards. Optional surface treatments like galvanizing, black painting, or anti-corrosion coatings enhance durability in harsh environments. The seamless construction ensures no weld seams, providing uniform strength and leak-proof performance for fluid transport.

Compared to international standards like ASTM A106 or ASTM A53, GB/T 8163 pipes are tailored for fluid transportation with similar mechanical properties but optimized for Chinese industrial requirements. For example, grade 20# is comparable to ASTM A106 Grade B, and Q345B aligns with ASTM A572 Gr.50. These pipes offer a cost-effective solution for fluid conveyance, addressing challenges like high-pressure and corrosive environments. They are widely used in Asia and globally due to their reliability and compliance with stringent quality standards.

GB 8163 steel pipes are a preferred choice for engineers and manufacturers in fluid transportation projects, ensuring efficient and safe delivery of liquids and gases in demanding industrial applications.

Technical Specifications

Chemical Composition of GB/T 8163 Steel Pipes
Steel Grade	C (%)	Si (%)	Mn (%)	P (%)	S (%)	Cr (%)	Ni (%)	Cu (%)	Mo (%)
10	0.07–0.14	0.17–0.37	0.35–0.65	≤0.035	≤0.035	≤0.15	≤0.25	≤0.25	—
20	0.17–0.24	0.17–0.37	0.35–0.65	≤0.035	≤0.035	≤0.25	≤0.25	≤0.25	—
Q345	0.12–0.20	0.20–0.55	1.20–1.60	≤0.045	≤0.045	≤0.30	≤0.50	≤0.30	≤0.10
45	0.42–0.50	0.17–0.37	0.50–0.80	≤0.035	≤0.035	≤0.25	≤0.25	≤0.25	—
20Cr	0.18–0.24	0.17–0.37	0.50–0.80	≤0.035	≤0.035	0.70–1.00	≤0.30	≤0.25	—

The Carbon Equivalent Value (CEV) of Q345, Q390, Q420 and Q460 shall be calculated using the following formula:

CEV = C+ Mn/6 + Cu/20 + (Cr + Mo + V)/5 + (Ni + Cu)/15

Mechanical Properties of GB/T 8163 Steel Pipes
Grade	Quality Levels	Tensile Properties			Impact Properties
Grade	Quality Levels	Tensile strength R_m	Lower yield strength R_eL	Elongation A	Impact temperature	Impact energy KV₂
10	—	335 – 475 MPa	205 MPa min	24 % min	—	—
20	—	410 – 530 MPa	245 MPa min	20 % min	—	—
Q345	A	470 – 630 MPa	345 MPa min	20 % min	—	—
	B			20 % min	+20 ℃	34 J
	C			21 % min	0 ℃
	D				-20 ℃
	E				-40 ℃	27 J
Q390	A	490 – 650 MPa	390 MPa min	18 % min	—	—
	B			18 % min	+20 ℃	34 J
	C			19 % min	0 ℃
	D				-20 ℃
	E				-40 ℃	27 J
Q420	A	520 – 680 MPa	420 MPa min	18 % min	—	—
	B			18 % min	+20 ℃	34 J
	C			19 % min	0 ℃
	D				-20 ℃
	E				-40 ℃	27 J
Q460	C	550 – 720 MPa	460 MPa min	17 % min	0 ℃	34 J
	D				-20 ℃	34 J
	E				-40 ℃	27 J

Steel Tube Dimensions and Tolerances
Types of steel tubes	Outer diameter		Wall thickness
Cold-rolled tubes	Tube sizes(mm)	Tolerances(mm)	Tube sizes (mm)	Tolerances(mm)
	＞30 - 50	±0.3	≤30	±10％
	＞50 - 219	±0.8％	≤30	±10％
Hot-rolled tubes	＞219	±1.0％	＞20	±10％

Designations and Descriptions of Tube Processing States
Processing Designation	Symbol	Description
Cold-finished/hard (cold-finished as-drawn)	BK	No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
Cold-finished/soft (lightly cold-worked)	BKW	After the last heat treatment there is a light finishing pass (cold drawing). With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits.
Annealed	GBK	After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum.
Normalized	NBK	The tubes are annealed above the upper transformation point in a controlled atmosphere or under vacuum.

Note:

Yield point requirements for seamless precision steel tubes vary significantly based on their delivery conditions, directly influencing their mechanical performance in industrial applications. These differences are critical for engineers selecting materials for specific load-bearing or forming needs.

For tubes delivered in the annealed (GBK) condition, the yield point is specified to be at least 50% of the ultimate tensile strength. This lower yield ratio ensures excellent ductility and formability, making GBK tubes suitable for applications requiring bending, flanging, or other cold-working processes where flexibility is paramount.

In contrast, tubes delivered in cold-finished/hard (BK) condition exhibit a significantly higher yield point due to work hardening from the drawing process. It is recommended that their yield point be ≥ 80% of the tensile strength. This high yield ratio provides enhanced rigidity and load-bearing capacity, ideal for structural components where dimensional stability under stress is critical.

Cold-finished/soft (BKW) condition represents a middle ground, with a recommended yield point of ≥ 70% of the tensile strength. This balance of strength and ductility makes BKW tubes versatile for applications that require both moderate formability and resistance to deformation, such as precision machinery parts or hydraulic system components.

These yield point specifications—tied directly to the degree of deformation during manufacturing—ensure that engineers can select the optimal delivery condition based on their application’s mechanical demands, whether prioritizing formability (GBK), maximum strength (BK), or a balanced performance (BKW).

Mechanical Properties and Testing Requirements for Steel Pipes
Steel Designation	Pipe Body (Seamless & Welded Pipe)				Spiral Weld		Whole Pipe
Steel Designation	Plastic Limit R_10.5 (N/mm²)	Tensile Strength R_m (N/mm² min.)	R_10.5/R_m (Max)	Elongation A (%) min.	HFW, SAW, COW Tensile Strength R_m (N/mm² min.)	SAW, COW Bending Mandrel Diameter	Whole Pipe
L245NB L245MB	245 to 440	415	0.80 0.85	22	Same as pipe body	3T	Every pipe must pass pressure test with no leaks or deformations
L290NB L290MB	290 to 440	415	0.85 0.85	21		3T
L360NB L360QB L360MB	360 to 510	460	0.85 0.88 0.85	20		4T
L415NB L415QB L415MB	415 to 565	520	0.85 0.88 0.85	18		5T
L450QB L450MB	450 to 570	535	0.90 0.87	18		6T
L485QB L485MB	485 to 605	570	0.90 0.90	18		6T
L555QB L555MB	555 to 675	625	0.90 0.90	18		6T

Inspection and Testing Frequency for Steel Pipes
Type of Inspection or Test	Frequency of Testing
Chemical analysis	One sample per heat number
Tensile test	One sample on each of the two steel pipes per lot
Impact test	Three samples on each of the two steel pipes per lot (for low alloy high strength structural steel pipes with an outside diameter of not less than 70mm, and a wall thickness of not less than 6.5mm)
Flattening test	One sample on each of the two steel pipes per lot (for steel pipes in grades 10, 20, Q345, Q390, with an outside diameter D>22~600mm, and S/D ratio not greater than 10%)
Flaring test	One sample on each of the two steel pipes per lot (for steel pipes in grades 10, 20, Q345, with an outside diameter of not greater than 76mm, and a wall thickness of not greater than 8mm)
Bending test	One sample on each of the two steel pipes per lot (for steel pipes with an outside diameter not greater than 22mm)
Hydrostatic test	Each pipe, dwell time is not less than 5s, can be replaced by eddy current test
Eddy current test	Each pipe
Magnetic flux leakage detection	Each pipe, can be replaced by eddy current test
Ultrasonic test	Each pipe
Dimension and shape	It should be measured with a measuring tool that meets accuracy requirements
Inner and outer surfaces	It should be visually inspected under sufficient lighting conditions

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A curated list of long-tail keywords for GB 8163 steel pipes, covering specifications, applications, and material properties, presented in a multi-column layout.

Standards and Specifications

• GB/T 8163-2018 seamless steel pipe specifications
• GB 8163 fluid transportation pipe standards
• GB/T 8163 carbon steel pipe properties
• Chinese standard seamless pipe tolerances

Applications

• GB 8163 pipes for oil and gas transportation
• GB/T 8163 seamless pipes for chemical engineering
• GB 8163 pipes for water transport
• Chinese standard pipes for fluid systems

Material and Grades

• GB/T 8163 20# carbon steel material
• GB 8163 pipe grades
• GB seamless pipe corrosion resistance

Manufacturing and Testing

• GB/T 8163 seamless pipe manufacturing process
• GB 8163 pipes hydrostatic testing
• GB seamless pipe quality control

Procurement and Suppliers

• GB 8163 steel pipes suppliers
• GB/T 8163 seamless pipe distributors
• Chinese standard fluid pipes price

Dimensions and Customization

• GB/T 8163 seamless pipe dimensions
• GB 8163 pipe tolerances
• GB seamless pipes custom lengths

Note: GB/T 8163-2018 covers seamless steel pipes for fluid transportation. For detailed specifications, refer to the GB/T 8163-2018 standard or contact a certified supplier.

GB 8163 steel pipes, under GB/T 8163-2018, are seamless carbon steel pipes designed for fluid transportation, suitable for conveying water, oil, gas, and other fluids in industries like petroleum, natural gas, and chemical engineering.

Common grades include 10#, 20#, Q345A, Q345B, Q345C, Q345D, Q345E, and 27SiMn, with 20# and Q345B widely used for fluid transport applications.

For 20#:
- C: 0.17–0.23%; Si: 0.17–0.37%; Mn: 0.35–0.65%; P: ≤0.035%; S: ≤0.035%

For 20#:
- Yield Strength: ≥235 MPa
- Tensile Strength: 410–550 MPa
- Elongation: ≥24%

Outer diameters: 21.3–914 mm; wall thicknesses: 2–60 mm; lengths: 6–12 m or custom. Tolerances: OD ±1%, wall thickness ±12.5% for hot-rolled, ±10% for cold-drawn.

Produced via hot-rolling or cold-drawing; cold-drawn pipes are annealed or tempered; optional treatments include galvanizing or anti-corrosion coatings.

Includes tensile, impact, flattening, hydrostatic, and optional ultrasonic testing to ensure quality and compliance.

Used in petroleum, natural gas, chemical engineering, power generation, and water supply systems for fluid transportation.

Marked with standard, grade, OD×WT, heat number, and manufacturer ID. Orders specify standard, grade, dimensions, length, and test certificates.

Common equivalents include:
- 20# ≈ ASTM A106 Gr.B
- Q345B ≈ ASTM A572 Gr.50
- Q345B ≈ EN 10025 S355

20G seamless pipe, often associated with GB/T 5310 for high-pressure boilers, is also used under GB/T 8163 as 20# for fluid transportation. It is a low-carbon steel grade known for its strength, toughness, and weldability, suitable for conveying fluids like water and oil.

For 20G (20# under GB/T 8163):
- Chemical Composition: C 0.17–0.23%; Si 0.17–0.37%; Mn 0.35–0.65%; P ≤0.035%; S ≤0.035%
- Mechanical Properties: Yield Strength ≥235 MPa; Tensile Strength 410–550 MPa; Elongation ≥24%

20G seamless pipes (20#) are used for fluid transportation in water supply systems, oil and gas pipelines, and low-pressure boiler systems, leveraging their weldability and moderate strength.

20G (20#) has lower carbon content (0.17–0.23% vs. ≤0.20%) and yield strength (≥235 MPa vs. ≥345 MPa) than Q345B, making it more suitable for applications requiring better weldability, while Q345B is preferred for higher-pressure fluid transport.

20G seamless pipes are manufactured via hot-rolling or cold-drawing, with cold-drawn pipes annealed or tempered to improve toughness and surface quality, suitable for fluid transportation.

GB/T 8163 Steel Pipes

GB/T 8163 Steel Pipes

GB/T 8163-2008 Fluid Transport Seamless Steel Pipe