GB steel pipes

The GB seamless steel pipe is made of steel ingot or solid tube blank through perforation, and then made by hot rolling, cold rolling or cold drawing. GB steel pipe has an important position in China’s steel pipe industry. Tubing shall be made seamless, plain or upset and coupling with high-seal connections. Coupling-free connections are possible.

GB国标

Guobiao standards or GB standards are the Chinese national standards issued by the Standardization Administration of China, the Chinese National Committee of the ISO and IEC. GB stands for Guobiao, Chinese for national standard. Mandatory standards are prefixed "GB".

Product name	Executive standard	Dimension (mm)	Steel code/ Steel grade
Used for manufacturing various low and medium pressure boilers.	GB 3087	19.05-114.3 x 2.0-14	10#, 20#
Low-temperature heat exchanger tubes seamless steel pipe	GB/T18984	19.05-351 x 2.0-14	06Ni3MoDG, 09DG, 09Mn2VDG, 10MnDG, 16MnDG
GB 8163 steel pipe is a seamless steel pipe for fluid transportation (GB/T8163-2018)	GB/T 8163	19.05-351 x 2.0-14	10#
High pressure and above pressure steam boiler tubes with high quality carbon structural.	GB5310	19.05-114.3 x 2.0-14	20G, 20MnG, 25MnG, 15MoG, 20MoG, 12CrMoG, 15CrMoG(T12/P12), 12CrMoG, 12Cr2MoWVTiB.

According to incomplete statistics, there are more than 240 national standard steel pipe production enterprises and more than 250 seamless steel pipe units.

Structural pipe (GB / T8162-1999) is used for the mechanical structure and general structure of seamless pipes.

Seamless pipe for liquid distribution (GB / T8163-1999) is a general seamless pipe for the transport of water, oil, gas and other liquids.

Seamless pipe is used for supply or transportation of water, oil, gas and other liquids under the specification of seamless pipe (GB / T8163-1999).

Correctly cooled or cold-rolled seamless steel pipe (GB3639-83) is used for mechanical structure, hydraulic equipment, high precision and surface finish. Selecting machines that produce seamless precision tubes or hydraulic equipment, etc., can greatly save mechanical processing time, improve material utilization, while helping to improve product quality.

Seamless pipe (GB3639-83) is basically improved the product quality though reduce the mechanical processing time and improve the material standard and quality. But it requires that it should be properly made by cooled or cold rolled seamless steel pipe (GB3639-83).

Low and medium pressure boiler pressure pipes (GB3087-1999) are used for the production of various low and medium pressure steam pipes, boiler water pipes and boilers with superheated steam, chimneys, small chimneys and domes use high quality hot rolled steel structures and cold drawn (laminated) seamless pipes.

Low and medium pressure boiler pressure pipe (GB3087-1999) is specialised for making of various low and medium pressure steam pipes, boiler water pipes and boilers with superheated steam, chimneys, and small chimneys.

High-pressure steam boiler pipe (GB5310-1995) is used for the production of high pressure and on the boiler surface pressure of hot water pipes made of high quality carbon steel, alloy steel and steel rust-free. (Working pressure is greater than 9.8Mpa, working temperature 540-650 degrees Celsius)

High quality carbon steel, alloy steel and steels are always required high pressure steam boiler pipe (GB5310-1995) for transportation and holding for liquid, steam, etc.

Pipeline for geological drilling (YB235-70) is a steel pipe for core drilling. It can be divided into drill pipe, neck drill, core tube, shell tube and sediment.

Core drilling is done though geological drilling (YB235-70) steel pipe and it’s segregated into drill pipe, neck drill, core tube, shell tube and sediment.

Piping (GB / T9711.1) is the supply of natural gas and other liquids such as oil and other seamless steel pipes (such as underground pipes and low temperature pipes).

High Pressure Cylinder Tube (GB18248) is used to produce oxygen cylinders, cylinder cylinders, natural gas cylinders, energy cylinders and other gas cylinders for seamless steel tubes.

Seamless steel pipe (GB / T9711.1) is used for the transporting and supplying of natural gas and other liquids such as oil.

Oxygen cylinders, cylinder cylinders, natural gas cylinders, energy cylinders and other gas cylinders is built by the High Pressure Cylinder Tube (GB18248) for seamless steel tubes.

Half-shaft automobile with seamless pipe (GB3088-82) is the manufacture of automobile tires and axles made of high-quality carbon structural steel and alloy steel pipes that melt the alloy structure.

Seamless pipe can be used in manufacturing of automobile tire and most of essential component of automobile industries. This specification consider under the standard of Half-shaft automobile with seamless pipe (GB3088-82).

Seamless steel pipe for ships (GB5213-85) is the production of grade I pressure piping, pressure pipe systems, boilers and seamless steel pipe coils. Carbon steel seamless pipe temperature does not exceed 450 ℃, seamless steel alloy steel pipe temperature of more than 450 ℃.

If the carbon steel pipe temperature does not exceed 450 ℃, it can be used for the production of grade I pressure piping and it consider under the standard of Seamless steel pipe for ships (GB5213-85)

Stainless steel structural stainless steel (GB / T14975-1994) is widely used in the fields of chemicals, petroleum, textiles, medical, food, machinery and other industries. Welded pipe and structural parts and parts made of hot stamping stainless steel, squeeze and seamless tubes.

Stainless steel structural steel (GB / T14975-1994) is used for the purpose of chemicals, petroleum, textiles, medical, food, machinery and other essential purpose works in different industries. Stainless tube considers all the function of squeeze and moulding with help of welded pipes and structural parts.

Stainless steel pipe for liquid distribution (GB / T14976-1994) is a seamless (extruded) and cold (laminated) seamless pipe made of stainless steel to transport liquids.

Liquid transportation is highly appreciated by the use of stainless steel pipe (GB / T14976-1994) but it is mandatory that seamless steel is cold laminated.

High pressure hose for chemical fertilizer equipment (GB6479-2000) suitable for working temperature -40 – 400 ℃, working pressure of chemical equipment 10 – 30Ma and carbon steel structural pipe High-grade seamless steel and alloy tubes.

Chemical fertilizer equipment (GB6479-2000) is used for the high pressure hose and it suits under the temperature of -40 – 400 ℃, working pressure of chemical equipment 10 – 30Ma and carbon steel structural pipe High-grade seamless steel and alloy tubes.

Uncured Pipes for Cracking Petroleum (GB9948-88) is a furnace tube, heat exchanger and seamless pipe for refineries.

Drill Diamond Core Drill (GB3423-82) is used for drilling diamond core drill, core rod, seamless pipe.

Seamless pipe drill diamond core drill (GB3423-82) is used for the drilling of diamond.

Oil Drill Tubing (YB528-65) is a seamless tube that thickens or thickens at both oil drills. The steel pipe is divided into two types of wire and wireless, and the wire is connected to the joint.

Diesel engine with high pressure pipe (GB3093-86) is the production of diesel injection system for high pressure pipe with no welded pipe.

Diesel engine with high pressure pipe (GB3093-86) is used for the production of diesel injection system for high pressure pipe, it doesn’t required welded pipe.

The internal precision pipe for hydraulic and pneumatic cylinders (GB8713-88) is a precision seamless pipe that is cold-rolled or cold-rolled with an accurate inner diameter for the production of hydraulic cylinders. and pneumatic. Columns, columns, can also be used for other cylinders and columns.

The production of hydraulic cylinders and pneumatic Columns, Columns these products require proper precision seamless pipe and the pipe should be cold- rolled or cold –rolled with an accurate inner diameter.

GB steel pipe size and tolerance

Deviation level	Standardized outer diameter tolerance
D1	±1.5%，min ±0.75 mm
D2	±1.0%。min ±0.50 mm
D3	±0.75%．min±0.30 mm
D4	±0.50%。min ±0.10 mm

National standard steel pipe weight formula: [(outer diameter - wall thickness) * wall thickness] * 0.02466 = kg / m (weight per meter)

Process	Size(mm)		Tolerance
Hot-rolled	O.D.	<351	+/-1.0% D(+/-0.50min)
		>=351	+/-1.25% D
	W.T.	<=25	+/-12.5% S(+/-0.40 min)
Cold drawn	O.D.	<=30	+/-0.20
		30-50	+/-0.30
		>50	+/-0.75% D
	W.T.	<=3	+12.5% S, -10% S
		>3	+/-10% S