Shandong JINBAICHENG Metal Materials Co., Ltd

Hot Rolled Straight Seam Welded Pipe

Short Description:

Straight seam welded pipes, steel pipes made of hot-rolled or cold-rolled steel plates or steel strip coils welded on welding equipment, are all called straight seam welded pipes. (The name is given because the welds of the steel pipe are in a straight line).

Product Detail

Product Tags

Product Introduction

Place of Origin: Shandong, China
Application: Hydraulic hose
Whether alloy: Yes
Alloy cross-section shape: round
Special tube: API
Tube outer diameter: 13.7-609.6 mm
Thickness: 1-50 mm
Standards: API, bs, ASTM, GB, JIS, DIN, API 5CT, API 5L, BS EN10025, ASTM A106-2006, ASTM A53-2007, GB 5310-1995, GB 3087-1999, GB/T 8163-1999, GB/T 8162-1909, JIS G2309, JIS G3444-2006, DIN 2391, DIN 17175, DIN 2448, DIN 2444
Process: Cold rolled

Grades: 16mn, A53(A,B), A106(B,C), 10#, 20#, 45,Q2 Q345, 15crmo, 12Cr1MoV, 12CrMo, 34CrMo4, 30CrMo, St52.4, ST37.4, 16mn, A53 -A369, 10#-45#, Q195-Q345, Cr-Mo alloy, ST35-ST52 ±5%
Processing services: bending, punching, cutting
Product name: Hot-dip galvanized round steel pipe GI pipe
Galvanized pipe surface: galvanized, black and color spray paint, according to customer requirements
Material: SAE1010/1020/1045, Q345, Q235,
Purpose: low pressure liquid, water, gas, oil, line pipe,
Greenhouse length: 3-12M
Certificate: API, ISO Ce
Certification: ISO

Product Display

Welded pipe2
Welded pipe4
Welded pipe3


Among them, according to different purposes, there are different back-end production processes. (It can be roughly divided into scaffold pipes, fluid pipes, wire sleeves, bracket pipes, guardrail pipes, etc.). Straight seam welded pipe standard GB/T3091-2008 and low pressure fluid welded pipe is a kind of straight seam welded pipe. Generally, water and gas are transported after the welding is completed. The current low pressure fluid pipe is better than ordinary welded pipe. The price of welded pipe is a bit higher (according to the current market price, it is about 80 yuan higher) For example: the price of welded pipe fluid pipe 1 inch (DN25) (that is Φ33.5*3.25) is about 4300 per ton, while the price of ordinary straight The seam welded pipe is around 4200.


Description of the main production process of large-diameter straight seam welded pipe:

1. Plate inspection: After the steel plate used to manufacture large-diameter submerged arc welded straight seam steel pipe enters the production line, the whole plate is first subjected to ultrasonic inspection;

2. Edge milling: double-sided milling of the two edges of the steel plate by an edge milling machine to achieve the required plate width, plate edge parallelism and bevel shape;

3. Pre-bending: Use a pre-bending machine to pre-bend the edge of the board, so that the edge of the board has a curvature that meets the requirements;

4. Forming: First half of the pre-bent steel plate is pressed into a "J" shape on the JCO forming machine through multiple stepping steps, and then the other half of the steel plate is also bent and pressed into a "C" shape, and finally an opening is formed "O" shape;

5. Pre-welding: Join the formed longitudinally welded steel pipes and use gas shielded welding (MAG) for continuous welding;

6. Internal welding: adopt longitudinal multi-wire submerged arc welding (up to four wires) to weld on the inner side of the straight seam steel pipe;

7. External welding: use longitudinal multi-wire submerged arc welding to weld on the outside of the longitudinal submerged arc welded steel pipe;

8. Ultrasonic inspection I: 100% inspection of the inner and outer welds of the longitudinally welded steel pipe and the base materials on both sides of the weld;

9. X-ray inspection I: 100% X-ray industrial television inspection of the inner and outer welds, using an image processing system to ensure the sensitivity of flaw detection;

10. Diameter expansion: expand the total length of the submerged arc welded straight seam steel pipe to improve the dimensional accuracy of the steel pipe and improve the distribution of the internal stress of the steel pipe;

11. Hydraulic test: The expanded steel pipes are inspected one by one on the hydraulic testing machine to ensure that the steel pipe meets the test pressure required by the standard. The machine has automatic recording and storage functions;

12. Chamfering: Process the pipe end of the steel pipe that has passed the inspection to meet the required pipe end groove size;

13. Ultrasonic inspection Ⅱ: Perform ultrasonic inspection again one by one to check the possible defects of the longitudinally welded steel pipe after diameter expansion and water pressure;

14. X-ray inspection Ⅱ: X-ray industrial television inspection and filming of pipe end welds on steel pipes after expansion and hydraulic test;

15. Tube end magnetic particle inspection: carry out this inspection to find tube end defects;

16. Anti-corrosion and coating: Qualified steel pipes are anti-corrosion and coating according to user requirements.

Standard Control

1. Generally welded pipes are used for the transportation of generally lower pressure fluids such as water, gas, air, oil and heating steam.

2. Ordinary carbon steel wire casing (GB3640-88) is a steel pipe used to protect wires in electrical installation projects such as industrial and civil construction and installation of machinery and equipment.

3. Straight seam electric welded pipe (YB242-63) is a steel pipe whose weld seam is parallel to the longitudinal direction of the steel pipe. Usually divided into metric electric welded pipes, electric welded thin-walled pipes, transformer cooling oil pipes and so on.

4. Spiral submerged arc welded pipe (SY5036-83) for pressure-bearing fluid conveying is a hot-rolled steel strip as a tube blank, which is spirally formed at regular temperature and welded by double-sided submerged arc welding. It is used for pressure-bearing fluid conveyance. Seam the steel pipe. The steel pipe has strong pressure-bearing capacity and good welding performance. After various strict scientific inspections and tests, it is safe and reliable to use. The steel pipe has a large diameter, high transmission efficiency, and can save investment in laying pipelines. Mainly used in pipelines for transporting oil and natural gas.

5. Spiral seam high-frequency welded pipes for pressure-bearing fluid transportation (SY5038-83) are made of hot-rolled steel strip coils, which are spirally formed at regular temperatures and welded by high-frequency lap welding. They are used for pressure-bearing fluid transportation. Spiral seam high frequency welded steel pipe. The steel pipe has strong pressure-bearing capacity and good plasticity, which is convenient for welding and processing. After various strict and scientific inspections and tests, it is safe and reliable to use. The steel pipe has a large diameter and high transmission efficiency. It can save investment in laying pipelines. Mainly used to lay pipelines for transporting oil and natural gas.

6. Spiral seam submerged arc welded steel pipe (SY5037-83) for general low-pressure fluid transportation is made of hot-rolled steel strip coils, which are spirally formed at regular temperature, and are made by double-sided automatic submerged arc welding or single-sided welding. Submerged arc welded steel pipes for general low-pressure fluid transportation such as water, gas, air and steam.

Longitudinal welded pipe specification table

Specification Outer diameter National standard wall thickness Welding Management Theory Weight Table
4Minute 15 1/2Inch 21.25 2.75 1.26
6Minute 20 3/4Inch 26.75 2.75 1.63
1Inch 25 1Inch 33.3 3.25 2.42
1.2Inch 32 11/4Inch 42.25 3.25 3.13
1.5Inch 40 11/2Inch 48 3.5 3.84
2Inch 50 2Inch 60 3.5 4.88
2.5Inch 70 21/2Inch 75.5 3.75 6.64
3Inch 80 3Inch 88.5 4.0 8.34
4Inch 100 4Inch 114 4.0 10.85
5Inch 125 5v 140 4.5 15.04
6Inch 150 6Inch 165 4.5 17.81
8Inch 200 8Inch 219 6 31.52

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