20G seamless steel pipe

GB 5310 20G High Pressure Boiler Tubes

GB 5310 20G high pressure seamless boiler tubes are a type of steel tube designed for use in high-pressure and high-temperature environments.

A 20G seamless steel pipe is a pipe made from 20G steel, known for its high temperature resistance and efficient heat transfer properties.

Is our main production of steel, we can provide 20G Seamless pipe with high quality and competitive price. Here to introduce you to our 20G seamless pipe basic chemical properties and mechanical properties.

The GB 5310 standard applies to seamless pipes for steam boilers and pipelines that are high pressure and above. The 20G steel pipe is the national standard steel grade for GB 5310. The foreign corresponding brand is Germany ST45.

High-pressure boiler tubes are a type of seamless steel pipe. They have very high requirements on the tightness of the steel pipes. The production method is the same as that of seamless tubes, and the requirements are basically the same.

Characteristics and Features

The 20G seamless steel pipe boasts several characteristics that make it an indispensable component in industrial applications:

  1. High Temperature Resistance: The 20G steel's composition allows the pipe to withstand elevated temperatures, making it suitable for applications involving heat transfer and energy conversion.

  2. Seamless Design: The seamless manufacturing process ensures uniformity and eliminates the risk of weak points or leaks, enhancing the overall integrity of the pipe.

  3. Efficient Heat Transfer: The properties of 20G steel facilitate efficient heat exchange, making the pipe ideal for transferring thermal energy between fluids.

  4. Corrosion Resistance: The steel's composition provides inherent resistance to corrosion, extending the pipe's lifespan and reliability in various environments.

Benefits and Advantages

  1. Enhanced Efficiency: The exceptional heat transfer properties of 20G steel contribute to efficient energy conversion, ensuring optimal performance in boilers and heat exchangers.

  2. Reliability: The seamless design and high tensile strength of 20G steel pipes enhance their reliability and safety in demanding industrial environments.

  3. Long Service Life: The corrosion-resistant nature of 20G steel extends the service life of the pipes, reducing maintenance requirements and downtime.

20G seamless pipes are used for a boiler in Uzbekistan

20G seamless pipes are used for a boiler in Uzbekistan

Applications of 20G Seamless Steel Pipe

The versatile nature of 20G seamless steel pipes makes them suitable for a range of industrial applications:

  1. Boilers: In the power generation sector, 20G pipes are used as superheater tubes, reheater tubes, and waterwall tubes in boilers, facilitating the exchange of heat and steam generation.

  2. Heat Exchangers: These pipes play a crucial role in heat exchangers, where they enable efficient transfer of thermal energy between fluids in different industrial processes.

  3. Petroleum Industry: The pipes find application in petroleum refineries for transporting high-temperature and high-pressure fluids.

Considerations for Usage

When incorporating 20G seamless steel pipes into industrial systems, the following factors should be considered:

  1. Operating Conditions: Ensure that the pipes are suitable for the specific temperature, pressure, and fluid characteristics of the application.

  2. Compatibility: Verify compatibility with other components and materials within the system to prevent potential issues.

Difference Between 20# and 20G Seamless Steel Pipes

When comparing 20# and 20G seamless steel pipes, there are several differences to consider.

First, the difference in use:

20# seamless steel pipes are used for structural pipes, fluid pipes, and low to medium pressure boiler pipes. On the other hand, 20G seamless steel pipes are specifically designed for high-pressure boiler tubes. Besides similar carbon content, 20G seamless steel pipes contain additional trace elements, making them more suitable for use in boilers and pressure vessels. They are widely utilized as pipelines for transporting fluids like oil, natural gas, water, and certain solid materials.

Second, the difference in characteristics:

20# seamless pipes have slightly higher strength compared to No. 15 steel and are rarely quenched, thus avoiding temper brittleness. They exhibit high plasticity during cold deformation, making them suitable for bending, calendering, flanging, and hammer arch processing. Their welding performance with arc and contact welding is good, but gas welding may result in cracks on workpieces with strict shape requirements or complex shapes. Cold-drawn or normalized pipes have better machinability than annealed pipes.

20G seamless steel pipes have strict requirements on the steel grades used in their manufacture. They must have high lasting strength, excellent oxidation corrosion resistance, and good organizational stability.

Third, the difference in price:

Due to differences in manufacturing processes and composition, 20G seamless steel pipes are priced higher than 20# seamless steel pipes.

What is 20G?

20G is a type of high-quality carbon structural steel, commonly used in the production of boiler tubes and pressure vessels due to its excellent mechanical properties and heat resistance.

20G is the steel material of GB 5310- 2008. GB 5310- 2008 standard is applicable to seamless tubes for making steam boiler whose pressure is high or higher and seamless tubes used as pipelines.

GB 5310 is a Chinese standard that outlines the specifications for seamless steel tubes used in high-pressure boilers. The designation "20G" refers to the material grade of these tubes, indicating that they are made from 20G steel, a low-carbon steel known for its excellent heat transfer properties and high tensile strength.

Chemical Compositions(%) of 20G

Chemical elements Data
Carbon 0.17-0.23
Silicon 0.17-0.37
Manganese 0.35-0.65
Phosphorus(max) 0.03
Sulfur(max) 0.03
Chromium(max) 0.25
Molybdenum(max) 0.15
Cuprum(max) 0.2
Nickel(max) 0.25
Vanadium(max) 0.08

PMI test for GB5310 20G steel

Positive Material Identification (PMI) test is performed on GB5310 20G steel to determine the composition of the material and ensure that it meets the specified chemical composition requirements.

PMI test for GB5310 20G steel PMI test for GB5310 20G steel
PMI test for GB5310 20G steel
PMI test for GB5310 20G steel
PMI test for GB5310 20G steel
PMI test for GB5310 20G steel

Mechanical Properties of 20G

Properties Data
Yield Strength (Mpa) 410-550
Tensile Strength (Mpa) 245
Elongation (%) 22

The W.T. tolerance of 16Mn

W.T.(S) Tolerance of W.T.
<3.5  +15%(+0.48mm min)
 -10%(+0.32mm min)
3.5-20 +15%,-10%
>20 D<219 ±10%
D≥219 +12.5%,-10%

GB5310 20G boiler steel pipe Other Name

20G High Pressure Boiler Pipe, GB5310 20G boiler steel pipe, 20G boiler steel pipe, 20G boiler pipe

Delivery Condition:

Annealed, Normalized, Normalized and Tempered

Inspection and Test:

Chemical Composition Inspection, Mechanical Properties Test(Tensile Strength,Yield Strength, Elongation, Flaring, Flattening, Bending, Hardness, Impact Test), Surface and Dimension Test,No-destructive Test, Hydrostatic Test.

Surface treatment:

Oil-dip, Varnish, Passivation, Phosphating, Shot Blasting

Delivery status
The steel tubes shall be delivered in a heat treated condition.

Length: 5800mm; 6000mm; 6096mm; 7315mm; 11800mm; 12000mm; and so on.

Max length: 16000mm, also U bending can be offered.

This inventory is part of the inventory, demand and other models in stock or order materials, please contact us.

Related GB 5310 20G High Pressure Boiler Tubes

Seamless tube processing

With years of expertise, we provide a diverse array of steel tube processing options. From sawing and machining tube blanks to intricate bending and upsetting operations, we actively assist you throughout your projects.

Our capabilities extend to eccentricity reduction and concentricity enhancement through turning and grinding. We excel in creating complex geometries using processes like rotary swaging and axial forming. Additionally, we offer property modifications via partial heat treatment, ensuring tailored solutions for your specific needs.

Variable wall thicknesses

Variable wall thicknesses

Drilling / stamping / lasering

Drilling / stamping / lasering

Peeling / roller burnishing

Peeling / roller burnishing

Cold forming

Cold forming







Thread rolling / threading

Thread rolling / threading

Partial hardening

Partial hardening

Turning / milling / grinding

Turning / milling / grinding

Reducing / expanding

Reducing / expanding



What is a seamless pipe used for?

Seamless steel pipe is regularly used in the transportation of fluids such as water, natural gas, waste and air. It is also regularly required in many high-pressure, high-corrosive environments such as in the oil & gas, power generation and pharmaceutical industries. Some common uses of seamless pipes include:

【H】 Ceramic lined pipe

Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.

【H】 Cast basalt lined steel pipe

Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.

【H】 Ceramic Tile Lined Pipes

Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.

【H】 Rare earth alloy wear-resistant pipe

The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.

【H】 Tubes Erosion Shields

Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.

【H】 ASTM A213 T91 Alloy Tube

The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.

Ni-Hard Wearback Pipes Ni-Hard Wearback Pipes