Marine Seamless Steel Pipe

Marine Seamless Steel Pipes are a sort of specialized steel pipes for marine purposes.

Marine Seamless Steel Pipe

 The pipes conform to requirements of ASTM, ASME, SPI, EN, JIS, DIN, GB, RS, ABS, BV, CCS, RINA… We can customize pipes in accordance with your requirements, available for large diameter, small diameter, heavy wall, thin wall… Please contact us for more information!

Two systems of ship and marine engineering demand roughly in three types of steel pipe:

Different ship and marine engineering, both conventional systems have a dedicated system.

Ship service life of 20 years. Many of the conventional system, bilge water, ballast, dewater sewage, air, measurement, injection, domestic water, fire, cargo oil stripping, breathable, inert gas, heating, washing, foam extinguishing sprinkler, vapor, liquid level telemetry, valve remote control systems, special ships also include a dedicated system for the transportation of liquefied petroleum gas (LPG), liquefied natural gas (LNG). Marine engineering service life of up to 30 years, or even longer. Marine engineering in addition to the conventional system, special drilling equipment systems, crude oil / LPG / LNG processing workflow system, special mooring system, flare system, and so on. It has been statistics, ship pipe annual consumption of 450 million tons, about 440,000, its standards are GB, YB, CB, 70% of the steel pipe connection. Only a 30-ton very large crude oil pipes for the amount of up to tens of kilometers, only steel pipe usage (including), there are about 1,500 tons, of course, the amount of 40,000 tons relative to the hull structure or limited. In addition, taking into account the same ship, to the construction of ships, as well as many other ships, so the cumulative dosage is also a lot of. And a 300,000 tons-class number of large FPSO pipe over 30,000, more than 90 km in length, which is the same tonnage level 2 to 3 times. Therefore, the shipbuilding industry has become a big user of steel pipe market.

Steel pipe in construct

Steel tube marine engineering applications, in addition to the above conventional system with a dedicated system, many constructed a large number of steel pipes, such as jacket, underwater steel piles, Casing, mooring bracket, helicopter platform, torch tower. Type of steel pipe, material specifications, with the same diameter, reducers, different wall thickness, as well as a large number of Y, K, T-managed nodes. Such as jacket, steel piles, wellhead impermeable sleeve, mostly large diameter steel pipe sizes, are generally made of rolled steel. Their material for E36-Z35, D36-Z35, E36, D36. Such steel pipe standards have not with YB, CB, and mainly is GB712-2000. The production of steel pipe structure steel pipe manufacturing practice SY/T10002-2000 developed by China’s Petroleum Industry Standards and Technology Commission (CPSC). Since China does not have the specialized enterprises, are usually the purchase of steel plate from construction units, self-molding process.

Specifications of marine seamless steel pipe table 1 grade of seamless steel pipe (pressure tubing)

Pipe Range I
Designed Pressure(Mpa) Designed Temperature (℃) Designed Pressure (Mpa) Designed Temperature (℃) Designed Pressure (Mpa) Designed Temperature (℃)
>
Steam and Hot Oil 1.6 300 0.7-1.6 170-300 0.7 170
Fuel Oil 1.6 150 0.7-1.6 60-150 0.7 60
Other Media 4 300 1.6-7.0 200-300 1.6 200

Note:

When the designed pressure and temperature reach the ones in the above Class I, this steel pipe belongs to Class I pipe. If it meets the pressure and temperature of Class II, it is defined to be the Class II pipe.

Other media refer to air, water, lubricating oil and hydraulic oil.

Class III seamless steel tubes can be manufactured in accordance with the national standards approved by the ship inspection department.

1) As for the seamless steel pipe for boiler and super heater purpose, the working temperature of wall thickness does not exceed 450℃.

2) The dimension of marine seamless steel pipe should firstly select the general steel pipe size in the first group of GB/T7395-1998 table one. The outside diameter of steel tube should choose the standard outside diameter size in the first series of GB/T7395-1998. We can also produce pipes with other specifications not appear in the GB/T7395-1998 table one.

Steel pipe for special purpose

Special purpose steel special steel pipe used in the specific working environment and the working medium. Undersea pipeline is typical specialty steel pipe, the demand for larger, high strength, small tolerances, good corrosion resistance. Currently, the pipeline production is only in its infancy, because the welding materials, corrosion resistance or less Specifications (diameter and wall thickness), expensive, etc. China’s offshore crude oil need insulation transport. The past, using the double pipe insulation structure, safe and reliable. But as a protective pipe steel pipe is very economical, and offshore pipe laying ago, have to carry out internal and external pipe welding, greatly reducing the efficiency of the pipe laying, to cause installation costs increase exponentially. Into the 21st century, it has launched a concrete counterweight steel pipe.

Its structure is (from inside to outside):

anti-corrosion layer of steel, epoxy powder (FBE), polyurethane insulation, polyethylene (PE) jacket tube, reinforced concrete counterweight layer (the internal configuration of the steel mesh). This type of special steel, China has imported from abroad, such as the Bohai Penglai 19-3 oil field, a project using Malaysian BREDEROPRICE company products. China after research and testing, and in 2002 built in Tanggu, China’s first concrete with heavy steel pipe production line, has thousands of kilometers of pipelines for offshore oilfield products. It is reported that, using this steel per kilometer subsea pipeline to reduce the cost of 50 million to 100 million, and greatly reduce the cost of offshore oilfield development, so that a number of marginal oil fields to be cost-effective to develop.

Specifications of Marine Seamless Steel Pipe Table 1 Grade of Seamless Steel Pipe (Pressure Tubing)

Classification of ships

Seamless steel tube and pipe for ship building usage and Chemical compisition(%)

Society Standard or usage Steel grade C Si Mn P S Cr Ni Cu Al Mo V P+S
GLR Non alloly GL-R 410 ≤0.21 ≤0.35 ≤1.4 ≤0.025 ≤0.02 - - - ≥0.020 - - -
GB 18248 37Mn 0.34~0.40 0.1~0.30 1.35~1.65 ≤0.03 ≤0.03 ≤0.3 ≤0.3 ≤0.2 - - - ≤0.055
EN 10297 34CrMo4 0.3~0.37 ≤0.4 0.6~0.90 ≤0.035 ≤0.035 0.9~1.20 - - - 0.15~0.30 - -
DNV for pressure ASTM A53/A53M A53B ≤0.3 - ≤1.2 ≤0.05 ≤0.045 ≤0.4 ≤0.4 ≤0.4 - -
0.15 0.08
ABS for pressure Grade 3 ≤0.3 - ≤1.2 ≤0.05 ≤0.045 ≤0.4 ≤0.4 ≤0.4 - ≤0.15 ≤0.08 -
BV for pressure 410HB ≤0.21 ≤0.35 0.4~1.20 ≤0.04 ≤0.04 - - - - - - -
LR for pressure 410 ≤0.21 ≤0.35 0.4~1.20 ≤0.045 ≤0.045 ≤0.25 ≤0.3 ≤0.3 - - -
KR for pressure RST138 ≤0.25 ≤0.35 0.3~0.90 ≤0.04 ≤0.04 - - - - - - -
RST142 ≤0.3 0.3~1.00 ≤0.04 ≤0.04 - - - - - - -
RST238 ≤0.25 0.1~0.35 0.3~1.10 ≤0.035 ≤0.035 - - - - - - -
RST242 ≤0.3 0.3~1.40 - - - - - - -
RST249 ≤0.33 0.3~1.50 - - - - - - -
RST338 ≤0.25 0.3~0.90 - - - - - - -
RST342 ≤0.3 0.3~1.00 - - - - - - -
NK for pressure grade 1 No3/ KSTPG 42 ≤0.3 ≤0.35 0.3~1.00 ≤0.04 ≤0.04 - - - - - - -
CCS for pressure 360 ≤0.17 ≤0.35 0.4~0.80 ≤0.04 ≤0.04 ≤0.25 ≤0.3 ≤0.3 ≤0.10
410 ≤0.21 ≤0.35 0.4~1.20 ≤0.04 ≤0.04 ≤0.25 ≤0.3 ≤0.3 ≤0.10
460 ≤0.22 ≤0.35 0.8~1.40 ≤0.04 ≤0.04 ≤0.25 ≤0.3 ≤0.3 ≤0.10
490 ≤0.23 ≤0.35 0.8~1.50 ≤0.04 ≤0.04 ≤0.25 ≤0.3 ≤0.3 ≤0.1

Note:
residual elements:Cr≤0.25%, Mo≤0.10%, Ni≤0.30%, Cu≤0.30%aggregate≤0.70%

Appication:

Model N0.of major steel tubes

What is a seamless pipe used for?

  1. Oil and Gas Industry: Seamless pipes are extensively used in the oil and gas industry for transporting fluids such as crude oil, natural gas, and petroleum products. They are capable of withstanding high-pressure and high-temperature conditions, making them suitable for oil and gas exploration, production, and transportation.
  2. Petrochemical Industry: Seamless pipes find applications in the petrochemical industry for transporting chemicals, gases, and other hazardous substances. They are resistant to corrosion and can handle aggressive media, making them ideal for petrochemical plants and refineries.
  3. Power Generation: Seamless pipes are used in power plants for various applications, including steam pipelines, boiler tubes, and turbine piping. They can withstand high temperatures and pressures, making them suitable for power generation through thermal and nuclear processes.
  4. Automotive Industry: Seamless pipes are used in the automotive industry for manufacturing exhaust systems, fuel injection systems, and hydraulic lines. They provide excellent dimensional accuracy, strength, and resistance to corrosion, ensuring efficient and reliable performance in automotive applications.
  5. Construction and Infrastructure: Seamless pipes are used in construction projects for various applications, including structural support, water supply systems, sewage systems, and underground pipelines. They offer high strength and durability, ensuring long-lasting and reliable infrastructure.
  6. Mechanical and Engineering Applications: Seamless pipes are widely used in mechanical and engineering applications, such as machinery, equipment, and tool manufacturing. They are used for conveying fluids, gases, and solids in various industries, including manufacturing, aerospace, and defense.
  7. Heat Exchangers and Boilers: Seamless pipes are utilized in heat exchangers and boilers for efficient heat transfer. They are suitable for carrying hot fluids and steam at high temperatures and pressures, making them essential components in industries such as power generation, chemical processing, and HVAC systems.

It's important to note that the above applications are just a few examples, and seamless pipes have a wide range of uses in many other industries and sectors where reliable and efficient fluid transportation is required.

Main products and application

Steel Grade Standard Application
GB(China) ASME(USA) DIN/EN(Euro) JIS(Jpan)
Carbon steel 10
20
20G
20MnG
25MnG
Q345B/C/D/E
A106
SA-106B
SA-106C
SA-192
SA-210A1
SA-210C
St35.8
St45.8
P235GH
P265GH
STB340
STB410
STB510
Economizer tube Water wall tube, pipeline, header pipe, Petrochemical furnace tube, heat exchange tube
Mo steel 15MoG
20MoG
SA-209 T1
SA-209 T1a
SA-209 T1b
16Mo3 15Mo3
16Mo3
Water wall tube
Superheater tube
Reheater tube
Cr-Mo Steel
Cr-Mo-V steel
12Cr1MoG
12Cr2MoWVTiB
  12Cr1MoV
14MoV63
  Superheater tube
Reheater tube,
Pipeline, Header pipe, Petrochemical furnace tube, Heat exchange tube
Cr-Mo-Steel
Cr-Mo-W Steel
Cr-Mo Steel
Cr-Mo-W steel
12CrMoG
15CrMoG
12Cr2MoG
10Cr9Mo1VNbN
10Cr9MoW2VNbBN
12Cr1Mo
12Cr5Mol/NT
12Cr9Mol/NT
T11/P11
T12/P12
T22/P22
T23/P23
T24/P24
T5/P5
T9/P9
T91/P91
T92/P92
10CrMo5-5
12CrMo4-5
10CrMo9-10
7CrWVMoNb9-6
7CrMoVTIB10-10
X10CrMoVNb9-1
X10CrWMoVNb9-2
X11CrMo5+l/NT
X11CrMo9-1+l/NT
STB20
STB22
STB23
STB24
STB25
STB26
Superheater tube, Reheater tube, Main steam pipe, Pipleline, Header pip, Petrochemical furnace tube, Heat exchange tube
Carbon steel
Ni steel
16MnDG
10MnDG
09DG
A333-1
SA-333-1
A333-6
SA-333-6
A333-3
SA-333-3
  STPL380
STPL450
Tube & pipe for Low-temperature service
Austentic Stainless steel   ---   AP304  TP304H
TP321 TP321H
TP347 TP347H
TP316 TP316H
S30432 TP310HCbN
    ---   Superheater tube
Reheater tube

Dimension tolerances of seamless steel pipe

Pipe types Pipe Szie(mm) Tolerances
Hot rolled OD <50 ±0.50mm
≥50 ±1%
WT <4 ±12.5%
≥4-20 +15%, -12.5%
>20 ±12.5%
Cold drawn OD 6-10 ±0.20mm
10-30 ±0.40mm
30-50 ±0.45
>50 ±1%
WT <1 ±0.15mm
>1-3 + 15%, – 10%
>3 + 12.5%, – 10%

Tolerances on out diameter

For pipe over 10 inches as a special OD tolerance pipe, the OD shall within vary +1% /-1%.

Standard Hot finished seamless tube Cold flnished seamless tube
Out diameter
(mm)
Tolerance Out diameter
(mm)
Tolerance
EN10216-1
EN10216-2
DIN17175
≤100  +/-0.75%
(min.+/-0.5mm)
All  +/-0.5%
(min. +/-0.30mm)
>100  +/-0.90%
GB/T 3087 ≤460  +/-0.75%
(min.+/-0.5mm)
 10-30   +/-0.40mm
>30-50  +/-0.45mm
>50  +/-1.0%
GB/T 5310
GB/T 9948
GB/T 6479
<57  +/-0.40mm ≤30  +/-0.20mm 
 57-325   +/-0.75% >30-50   +/-0.30mm 
>325-460  +1%,-2mm >50  +/-0.8% 
ASME SA-179M
ASME SA-192M
ASME SA-209M
ASME SA-210M
ASME SA-213M
JIS G 3461
JIS G 3461
≤101.6  +0.4, -0.8mm <25.4  +/-0.10mm
>25.4-38.1  +/-0.15mm
>38.1-50.8  +/-0.20mm 
101.6-190.5  +0.4, -1.2mm >50.8-63.5  +/-0.25mm
>63.5-76.2  +/-0.30mm 
>76.2  +/-0.38mm
ASME SA106
ASME SA335
≤48.3  +/-0.40mm  ≤48.3  +/-0.40mm
 48.3-114.3  +/-0.79mm 
114.4-219.1  +1.59, -0.79mm 
219.2-323.9  +2.38, -0.79mm >48.3  +/-0.79mm 
>324  +/-1.0%

Tolerance on dimension

For standard pipe, except as provided for thin-wall pipe, the tolerances of diameter shall be in accordance with the following table:

Standard Hot finished seamless tube Cold flnished seamless tube
Out diameter
(mm)
Tolerance Out diameter
(mm)
Tolerance
EN10216-1
EN10216-2
DIN17175
≤100  +/-0.75%
(min.+/-0.5mm)
All  +/-0.5%
(min. +/-0.30mm)
>100  +/-0.90%
GB/T 3087 ≤460  +/-0.75%
(min.+/-0.5mm)
 10-30   +/-0.40mm
>30-50  +/-0.45mm
>50  +/-1.0%
GB/T 5310
GB/T 9948
GB/T 6479
<57  +/-0.40mm ≤30  +/-0.20mm 
 57-325   +/-0.75% >30-50   +/-0.30mm 
>325-460  +1%,-2mm >50  +/-0.8% 
ASME SA-179M
ASME SA-192M
ASME SA-209M
ASME SA-210M
ASME SA-213M
JIS G 3461
JIS G 3461
≤101.6  +0.4, -0.8mm <25.4  +/-0.10mm
>25.4-38.1  +/-0.15mm
>38.1-50.8  +/-0.20mm 
101.6-190.5  +0.4, -1.2mm >50.8-63.5  +/-0.25mm
>63.5-76.2  +/-0.30mm 
>76.2  +/-0.38mm
ASME SA106
ASME SA335
≤48.3  +/-0.40mm  ≤48.3  +/-0.40mm
 48.3-114.3  +/-0.79mm 
114.4-219.1  +1.59, -0.79mm 
219.2-323.9  +2.38, -0.79mm >48.3  +/-0.79mm 
>324  +/-1.0%

Tolerances on wall thickness

The wall thickness at any point shall be within the below tolerance table.

Standard Hot finished seamless tube Cold flnished seamless tube
Out diameter
OD(mm)
Wall thickness
T(mm)
Tolerance Out diameter
(mm)
Wall Thickness
T(mm)
Tolerance
DIN17175 ≤130 S≤2Sn  +15%, -10%    -- All  +/-10%
(min. +/-0.2mm)
2Sn<S≤4Sn  +12.5%, -10% 
S>4Sn  +-/9%
>130 S≤0.05da  +17.5%, -12.5% 
0.05da<S≤0.11da  +/-12.5% 
S>0.11da  +/-10% 
EN 10216-1
EN 10216-2
 ≤219.1   -    +/-12.5%
(min.+/-0.4mm) 
 --  T/D≤0.025  +/-20% 
0.025<T/D≤0.050  +/-15% 
0.05<T/D≤0.10  +/-12.5% 
0.1<T/D  +/-10% 
GB/T 3087  --  ≤20  +15%,-12.5%
(min.+0.45, -0.35mm)
 --   1.0-3.0   +15%, -10% 
>20  +/-12.5%   --  >3  +12.5%, -10% 
GB/T 5310
GB/T 9948
GB/T 6479
 --  <4.0  +15%,-10%
(min.+0.48, -0.32mm)
 --   2-3   +12%,-10% 
 4-20   +12.5%,-10%  >3  +/-10% 
>20  +/-10%
ASME SA-179M
ASME SA-192M
ASME SA-209M
ASME SA-210M
ASME SA-231M
JIS G 3461
JIS G 3462
 --   2.41-3.8   +35%, -0%  ≤38.1  --   +20%,-0% 
 3.8-4.6   +33%,-0%  >38.1  --  22%,-0% 
>4.6  +28%,-0%   --   --   -- 
ASME SA-106
ASME SA-335
 --  All  +/12.5%    All  +/-10% 

Available size range

Table 1, size for cold-drawn or cold rolled tube (Unit:mm)

   W.T.
O.D.
2.5 3 3.2 3.5 4.0 4.5 5 5.5 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 11.0 12.0 13.0 14.0 15.0 16.0
18                                            
19                                            
22                                            
24                                            
25                                            
28                                            
29                                            
30                                            
31.8                                            
35                                            
38                                            
40                                            
42                                            
45                                            
48                                            
50                                            
51                                            
54                                            
57                                            
60                                            
63.5                                            
68                                            
70                                            
73                                            
76                                            
83                                            
89                                            
   W.T.
O.D.
2.5 3 3.2 3.5 4.0 4.5 5 5.5 6.5 7.0 7.5 8.0   9.0 9.5 10.0 11.0 12.0 13.0 14.0 15.0 16.0

Note:

  1. The size in the table above is for the cold-drawn or cold-rolled tubes.
  2. The size of the green area is the regular specification, we can accept orders directly, but the yellow area shall be subject to a technical evaluation.
  3. The Out side diameter (O.D) and wall thickness (W.T.) of the tube should be complied.

At the request of the purchaser and specified in the purchase order, the steel tubes with other O.D. and W.T. can be produced after the review.

Size for hot-rolled tube (31.8-180mm)

(Unit:mm)

   W.T.
O.D.
3.2 3.5 3.6 4.0 4.5 5.0 5.5 5.6 6.0 7.0 7.1 7.5 8.0 8.5 8.8 9.0 9.5 10.0 11.0 12.0 12.5 13.0 14.0 14.2 15.0 16.0 17.0 17.5 18.0 19.0 20.0 22.2 24.0 25.0 30.0
31.8                                                                      
33.4                                                                      
35                                                                      
40                                                                      
42                                                                      
42.4                                                                      
44.5                                                                      
45                                                                      
48                                                                      
50                                                                      
51                                                                      
54                                                                      
57                                                                      
60                                                                      
63                                                                      
63.5                                                                      
68                                                                      
70                                                                      
71                                                                      
73                                                              
76                                                              
82                                                              
89                                                              
95                                                              
101.6                                                              
108                                                                      
114.3                                                              
121                                                              
127                                                                      
133                                                                      
140                                                                      
146                                                                      
152                                                                      
159                                                                      
165                                                                      
168                                                                      
180                                                                      

Size for hot-rolled tube (OD.:200-457mm)

(Unit:mm)

   W.T.
O.D.
6 6.4 6.7 7 7.4 7.6 9 9.5 10 14 16 20 25 30 32 35 40 46 50 52 55 60
200.03                                            
219.1                                            
244.5                                            
269.8                                            
273                                            
298.5                                            
325                                            
339.7                                            
351                                            
355.6                                            
365.1                                            
377                                            
402                                            
406.4                                            
426                                            
431.8                                            
457                                            

What is 10MnDG?

10MnDG is a type of seamless steel pipe that belongs to the family of high-pressure boiler tubes. It is a low-alloy steel pipe with a chemical composition that includes carbon (C), silicon (Si), manganese (Mn), phosphorus (P), sulfur (S), and other trace elements.

The chemical composition of 10MnDG typically includes:

10MnDG seamless steel pipe is mainly used in the manufacture of high-pressure and ultra-high-pressure boilers and pressure vessels. The pipes are designed to withstand high-pressure and high-temperature environments, making them suitable for use in applications such as power generation, chemical processing, and oil and gas refining.

10MnDG is a reliable material with excellent mechanical properties, including high strength, toughness, and resistance to creep deformation at high temperatures. These characteristics make it an ideal choice for use in critical applications where performance and reliability are essential.

Overall, 10MnDG seamless steel pipe is an important component of industrial piping systems, providing safe and efficient means for transporting fluids at high pressures and temperatures.

What is 16MnDG?

16MnDG is a type of seamless steel pipe that is commonly used in the manufacturing of high-pressure vessels and boilers. It belongs to the family of low-alloy steels and has a chemical composition that includes carbon, silicon, manganese, phosphorus, sulfur, and other trace elements.

The chemical composition of 16MnDG typically includes:

16MnDG seamless steel pipe has good mechanical properties, including high strength, toughness, and resistance to creep deformation at high temperatures. These characteristics make it an excellent choice for use in high-pressure and high-temperature environments, such as in the manufacture of boilers, pressure vessels, and other equipment used in power generation and chemical processing industries.

The seamless nature of 16MnDG pipes ensures uniformity and consistency in their structure, which makes them less prone to defects or failures. This enhances their reliability and safety, providing a secure means for transporting fluids at high pressures and temperatures.

Overall, 16MnDG seamless steel pipe is an important component of industrial piping systems, providing a reliable and efficient means for transporting fluids in harsh and demanding environments.

What is 09DG?

09DG is a type of seamless steel pipe that belongs to the family of high-temperature and pressure-resistant steel pipes. It has a chemical composition that includes carbon, silicon, manganese, phosphorus, sulfur, and other trace elements.

The chemical composition of 09DG typically includes:

09DG seamless steel pipe is designed to withstand high-temperature and high-pressure conditions, making it suitable for use in the manufacture of boilers, heat exchangers, and other equipment used in the power generation and chemical processing industries.

The seamless nature of 09DG pipes ensures that they have a homogeneous and consistent structure, which reduces the likelihood of defects or failures. This enhances their safety and reliability, providing a secure means for transporting fluids under high pressures and temperatures.

09DG seamless steel pipe has excellent mechanical properties, including high strength, good toughness, and resistance to creep deformation at high temperatures. These characteristics make it an ideal material for use in critical applications where performance and reliability are essential.

Overall, 09DG seamless steel pipe is an important component of industrial piping systems, providing a reliable and efficient means for transporting fluids at high pressures and temperatures.


Process

Cold drawn seamless steel tube deformed process

Cold Drawn Seamless Mechanical Tubing (CDS) is a cold drawn 1018/1026 steel tube which offers uniform tolerances, enhanced machinability and increased strength and tolerances compared to hot-rolled products.

Cold drawn seamless steel tube deformed process

Cold drawn steel tube is with hot-rolled steel coil as raw material, and tandem cold rolling pickled to remove oxide scale, its finished rolling hard roll, rolling hard volumes due to the continuous cold deformation caused by cold hardening strength, hardness increased indicators declined tough plastic, stamping performance will deteriorate, which can only be used for simple deformation of the parts.

Rolling hard roll can be used as the raw material of the hot-dip galvanizing plant, hot dip galvanizing line set annealing line. Rolling hard roll weight is generally 6 to 13.5 tons, the coil diameter of 610mm.

Hot rolled seamless steel pipe deformed process

Hot-rolled seamless steel pipe production base deformation process can be summarized as three stages: perforation, extension and finishing.

Hot rolled seamless steel pipe deformed process

The main purpose of the perforation process is to become a solid round billet piercing hollow shell. Capillary in the specifications, accuracy and surface quality can not meet the requirements of the finished product, further improvements are needed to deform the metal through. The main purpose of the stretching machine is further reduced sectional view (main compression wall) for a larger axial extension, so that the capillary improved dimensional accuracy, surface quality and organizational performance.

After stretching machine rolled steel pipe shortage collectively need further molding mill in order to achieve the requirements of the finished pipe. Rolled steel due to pass in the method widely used in the production of seamless steel tubes.

So far, due to the method pass rolling steel can be divided into two categories: core pension without rolling rolling (hollow body rolling), and with the mandrel. Sizing machines, reducing mill and stretch reducing mill belonging to the hole without mandrel type continuous rolling mills are generally coffin. Its main purpose is to reduce the diameter of the deformation process or sizing get finished steel, the wall thickness of process control, can make thinning, thickening or nearly unchanged.

All the traditional hole-type rolling machine with mandrel belong to extend machine. The main purpose is to reduce the deformation process perforated capillary wall thickness and outer diameter roll passes in the deformation zone and the mandrel posed, for a larger axial extension. At the same time a certain improvement in the organization, performance, accuracy, surface quality.

Cut to Length

Before cutting pipe and tubing

No matter the material, measure the diameter of the pipe or tube to be cut to ensure that you use the right-size tube cutter for the job. When determining how to make a straight cut, use a tape measure and a pencil or other writing instrument to mark on the surface where you want to cut. If possible, mark around the circumference of a pipe, especially when cutting with a handsaw. Ensure that a cut is as straight as possible by securing the pipe with a vise, clamp, miter box or even duct tape to keep the length from shifting out of place while cutting.

After cutting pipe and tubing

  • Unless a cut is perfectly clean, you should expect to remove burrs from around the edge, especially after sawing.
  • Use a deburring tool to clean the edge after tube cutting.
  • You may opt to use a metal file on the cut of a metal pipe.
Cut to length

The main manufacturing technology of seamless carbon steel pipe

1.Plug rolling production

The production equipment consists of punching machine, automatic pipe rolling machine, coiling machine, sizing machine and reducing machine. The round tube is inserted into the hollow of the thick-walled tube, and the axes of the two rollers form an oblique angle with the rolling line. In recent years, the inclination angle has increased from 6° to 12° to 13° to 17°, increasing the speed of the punch. When producing structural seamless pipe with a diameter greater than 250mm, secondary perforation is used to reduce the thickness of the hollow billet wall. New technologies have also been developed to enhance the perforation process and improve the quality of the capillary.

2. Continuous rolling production

The production equipment includes punching machine, continuous rolling mill, and tension reduction machine. The round billet is pierced into a hollow billet, then inserted into the mandrel, and continuously rolled by 7 to 9 two-roll mills. After rolling, the mandrel bar is taken out and reheated to reduce tension. In 2014, the annual output of 140mm continuous rolling mills is 0.4 to 600,000 tons, which is 2 to 4 times that of plug mills. The characteristics of this unit are suitable for the production of steel pipes with a diameter of 168mm or less. However, the equipment investment is large, the installed capacity is large, and the processing and manufacturing are complex.

3. Three-roll rolling production

Three-roll rolling production is mainly used to produce thick-walled seamless steel pipes with high dimensional accuracy. The wall thickness accuracy of the seamless steel pipe produced by this manufacturing process can reach plus or minus 5%, and the pipe accuracy is twice that of the seamless steel pipe produced by other methods. This manufacturing technique developed rapidly with the invention of the new three-high skew rolling mill in the 1960s. The new type of rolling mill is characterized by rapidly rotating the inlet rotary rack to change the expansion angle of the tail, thereby preventing the triangle from appearing at the tail, and expanding the ratio of the outer diameter to the wall thickness of the production varieties from 12 to 35, which can not only produce thin-walled seamless welded steel pipes , but also can improve production capacity.

4. Extrusion tube production

The peeled round base is first perforated or expanded, then heated by induction heating or a salt bath, coated with lubricant, and loaded into the extruder. The metal is squeezed into the pipe through the circular gap between the mandrel and the tip of the pen. This manufacturing process is mainly used for the production of superalloy tubes, specialty tubes, composite tubes and non-ferrous metal tubes. It has a wide range of production but low volumes. The production of extruded tubes has also grown in recent years due to improvements in die materials, lubricants and extrusion speeds.

5. Cold rolling (cold drawing) production

This manufacturing process is used to produce small-diameter precision-shaped thin-walled low-carbon steel pipes. It is characterized by the use of multi-stage cycle manufacturing technology. In the 1960s, it began to develop in the direction of high speed, multi-line, long stroke and long tube blank. In addition, small roller mills have also been developed, mainly for the production of precision tubes with a thickness of less than 1mm. The cold rolling equipment is complex, the tool processing is difficult, and the specification conversion is not flexible. And usually a combined process of cold rolling and cold drawing is used, that is, cold rolling is used to reduce the wall thickness to obtain larger deformation, and cold drawing technology is used to obtain various specifications.


Application

Alloy steel pipes are ideally suitable for chemical, petrochemicals, and other energy-related applications.

The alloy steel pipe adopts high quality carbon steel, alloy structural steel and stainless & heat resisting steel as raw material through hot rolling or cold drawn to be made.

Alloy steel can be used in process area where carbon steel has limitation such as

  • High-temperature services such as heater tubes
  • Low-temperature services such as cryogenic application
  • Very high presser service such as steam header

As an important element of steel products, alloy steel pipe can be divided into seamless steel pipe and welded steel pipe according to the manufacturing technique and tube billet shape.

Here you can see the common alloy steel grade that you will come across.

  • For Pipes: ASTM A335 Gr P1, P5, P11, P9
  • For Wrought Fittings: ASTM A234 Gr.WP5, WP9, WP11
  • For Forged Fittings: ASTM A182 F5, F9, F11 etc.

Why the application of alloy steel pipe is wider than others

application

There are many kinds of materials used for transport in industrial production. Specifically we will have more choices and it is not limited to the use of alloy steel pipe. But even in the face of more choices, many people tend to choose alloy steel pipe. People make their own choices will have their own reasons. This means the alloy steel pipe application has its own advantages. Compared with transmission lines made of other materials, after it meets the basic application requirements, its quantity is lighter. Then in the practical application of alloy steel pipe, it will have more advantages because of this. Besides its physical characteristic advantage, it also has economic advantages. The wide application of alloy steel pipe is with kinds of reasons. So in practical usage, we can exploit the advantages to the full, in this way can we get more profits in these applications of alloy steel pipe.

What requirements should alloy steel pipe application meet

The transportation of kinds of gases or liquids in production needs to rely on alloy steel pipe. This shows that the actual role of alloy steel pipe application is important. High temperature resistant and low temperature resistant is the tolerance of temperature. In the practical application of alloy steel pipe, there will be many materials need to be transported. However their temperatures are not the same. So this can be the basic requirement to alloy steel pipe. It needs more corrosion resistance. Corrosion resistant material is the best material during transporting, because it is corrosion resistant. So it can be used in more occasions. And it is definitely very convenient for users.

The biggest advantages of alloy steel pipe

Can be 100% recycled, environmentally friendly, energy-saving, resource conservation, national strategy, national policy to encourage the expansion of the field of application of high-pressure alloy pipe. Of alloy steel pipe total consumption accounted steel in the proportion is only half of the developed countries, to expand the field of use of the alloy steel pipe to provide a wider space for the development of the industry. The future needs of the average annual growth of China’s high-pressure alloy steel pipe long products up to 10-12%.

Specification, standard and identification of alloy steel pipes

Alloy Steel pipe contains substantial quantities of elements other than carbon such as nickel, chromium, silicon, manganese, tungsten, molybdenum, vanadium and limited amounts of other commonly accepted elements such as manganese, sulfur, silicon, and phosphorous.

Industries We Serve

Our team of experienced sales specialists proudly partners with gas and chemical processors, power generation plants, oil refineries, and related industries to offer piping components and value-added services.

The biggest advantages of alloy steel pipe can be 100% recycled, environmentally friendly, energy-saving, resource conservation, national strategy, national policy to encourage the expansion of the field of application of high-pressure alloy pipe. Of alloy tube total consumption accounted steel in the proportion is only half of the developed countries, to expand the field of use of the alloy tube to provide a wider space for the development of the industry. According to the Chinese Special Steel Association alloy pipe Branch Expert Group, the future needs of the average annual growth of China’s high-pressure alloy pipe long products up to 10-12%.


Inspection

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.

PMI

identification of the chemical composition of the metal used to manufacture the fitting. Uses PMI sensors, including X-ray fluorescence or optical emission spectrometry.

PMI
PMI
PMI
PMI
PMI
PMI

Size measurement

Size measurement
Size measurement
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Size measurement

Seamless pipes with compound bevels as per ASME B16-25 And ASTM A333

ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe

Delivery

Steel pipe delivery status(condition)

Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).

Condition on delivery of steel pipe

Term Symbol Explanation
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.

The general cold strip mills, volume should go through continuous annealing (CAPL unit) to eliminate cold hardening and rolling stress, or batch annealing reach the mechanical properties of the corresponding standard specifies. Cold rolled steel surface quality, appearance, dimensional accuracy better than hot-rolled plate, and right-rolled thin product thickness is about 0.18mm, so the majority of users favor.

Cold rolled steel coil substrate products deep processing of high value-added products. Such as electro-galvanized, hot dip galvanized, electro-galvanized fingerprint resistant, painted steel roll damping composite steel, PVC laminating steel plates, etc., so that the excellent quality of these products has a beautiful, high resistance to corrosion, has been widely used.

Cold rolled steel coil finishing after annealing, cut the head, tail, trimming, flattening, smooth, heavy volume, or longitudinal clipboard. Cold-rolled products are widely used in automobile manufacturing, household electrical appliances, instruments, switches, buildings, office furniture and other industries. Steel plate strapping package weight of 3 to 5 tons. Flat sub-volume typically 3 to 10 tons / volume. Coil diameter 6m.

Packing

Bare packing/bundle packing/crate packing/wooden protection at the both sides of tubes and suitably protected for sea-worthly delivery or as requested.

There are probably hundreds of different methods for packing a pipe, and most of them have merit, but there are two principles that are vital for any method to work prevent rusting and Sea transportation security.

Steel strips bunding for fixed pipes

Our packing can meet any needs of the customers.

Packing
Packing
Packing
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Packing
Packing

Placing steel pipes into containers

Packing
Packing
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FAQ

Q&A

Our team of experienced sales specialists proudly partners with gas and chemical processors, power generation plants, oil refineries, and related industries to offer piping components and value-added services.

The most important and desired changes in alloy steel are

Alloy steels are made by combining carbon steel with one or several alloying elements, such as manganese, silicon, nickel, titanium, copper, chromium and aluminum. These metals are added to produce specific properties that are not found in regular carbon steel. The elements are added in varying proportions (or combinations) making the material take on different aspects such as increased hardness, increased corrosion resistance, increased strength, improved formability (ductility); the weldability can also change.

Alloying Elements & Their Effects

Pipes, Tubes and Hollow Sections

Norms

Grade

Alloying Elements

Commonly used alloying elements and their effects are listed in the table given below.

Alloying Elements Effect on the Properties
Chromium Increases Resistance to corrosion   and oxidation. Increases hardenability and wear resistance. Increases high   temperature strength.
Nickel Increases hardenability. Improves   toughness. Increases impact strength at low temperatures.
Molybdenum Increases hardenability, high   temperature hardness, and wear resistance. Enhances the effects of other   alloying elements. Eliminate temper brittleness in steels. Increases high   temperature strength.
Manganese Increases hardenability. Combines   with sulfur to reduce its adverse effects.
Vanadium Increases hardenability, high   temperature hardness, and wear resistance. Improves fatigue resistance.
Titanium Strongest carbide former. Added to   stainless steel to prevent precipitation of chromium carbide.
Silicon Removes oxygen in steel making.   Improves toughness. Increases hardness ability
Boron Increases hardenability. Produces   fine grain size.
Aluminum Forms nitride in nitriding steels.   Produces fine grain size in casting. Removes oxygen in steel melting.
Cobalt Increases heat and wear   resistance.
Tungsten Increases hardness at elevated   temperatures. Refines grain size.

Hot products

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【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.