ERW Steel Pipe

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ERW Steel Pipe

The ERW steel pipe is also known as straight seam pipe. It is manufactured by using electric resistance welding. The weld lies inside the tube and is not visible from the outside. The tube is commonly used in low pressure fluid conveyance applications, such as the transfer of water, coal gas, air, oil, and steam. According to the wall thickness, the welded tube is classified into common types and thick-walled types. We can offer products with customized wall thickness according to clients' specific requirement with a thickness deviation of no more than 0.25 mm.

With sizes between 1/2 inch and 24 inch, our ERW steel pipes undergo strict inspections and tests, so as to make sure the welding quality, outer diameter precision, ovality, cut lengths, pipe end quality, wall thickness tolerance, and packaging quality are all conforming to API5L, ASTMA53, GB/T9711.1, or GB/T3091 standards. Also, we can manufacture the product according to the standard required by clients. Youfa is the biggest welded steel pipe manufacturer in China and our designed annual production capacity of straight seam tubes is 3.5 million tons.

1. Uncoiling
2. Strip Leveling
3. End Cutting
4. End Shearing and Welding
5. Accumulator
6. Forming
7. Induction Welding
8. Seam Heat Treatment
9. air/Water Cooling
10. Seam/Body UT
11. Sizing and Straightening
12. Cutting
13. Visual and Dimension Inspection
14. Hydrostatic Test
15. End Facing and Chamfering
16. Flattening Testing
17. Marking
18. Length-Measuring and Weighing
19. Seam/End UT
20. Coating
21. Storage

Connection Methods

1. Welding connection
Electrical welding connection is simple and convenient, and is mainly applicable for short distance applications.

2. Flanged connection

The connection method is easy and flexible, and the flanges can be conveniently replaced as well. However, the flange has to be carefully selected according to the design standard and the pressure required by the project.
(1) The flange's bolt diameter and length should conform to the related standard. After fastening, please make sure there are only 2-3 exposed screw threads which shouldn't greater than 1/2 of the bolt diameter.
(2) For generally flange connections, a rubber gasket with thickness of 3mm should be utilized. As for heating pipeline or water supply system pipeline connections, we recommend using 3mm asbestos gaskets. The gaskets should be concentric with the pipe, and have to be well positioned.

3. Threaded connection

Before thread connection, the screw thread has to be created in accordance with the tube diameter, and the threading can be completed by machines or manually. Generally speaking, thread generating for ERW steel pipes with nominal outside diameter between 15mm and 32mm should be completed in two times, three times for pipes with outside diameter between 40mm and 50mm, and three to four times for pipes with diameter above 70mm.

4. Grooved coupling

Clamp fittings make this connection method convenient and flexible, and the connection should conform to the regulations specified in CECS151:2003 Technical Specification for Grooved Coupling of Pipeline Engineering.
(1) Be sure the pipe end grooving is accurate, and the surface between the pipe end and the groove is smooth and offers fine quality.
(2) While grooving, please make sure the tube is horizontally placed and the tube axis is perpendicular to the grooving machine's working surface.
( 3) The groove's depth should be accurately controlled to meet national standards.

Installation Instructions
While installation, we recommend positioning the weld junction at the top, so as to extend the service life of the ERW steel pipe.

Packaging, Transportation, and Storage
1. ERW steel pipes for sea transportation have to be oiled, so as to avoid rusting caused by sea water. Meanwhile, we recommend packing them using strapping tapes to form a hexagon bundle. The screw threads of threaded tubes should be well packed to avoid damages.
2. During transportation, please handle the products carefully so as to keep them in good shape. Severe impacts many cause deformation or surface quality defects.
3. During storage, please keep the products away from rain water, acid or alkaline substances, and never place the welded pipes on ground directly, thus avoiding rusting or corrosion.

Technical Specifications
Size Range: 1/2 inch~24 inch (21.3~610mm)
Wall Thickness: 0.5~16mm
Standard: API 5L, ASTM A53, GB/T9711.1, GB/T3091.
Steel Grade: GR.A, GR.B, X42, X46, X52, X56, X60, X65, X70
End finish: Plain end, bevel end, thread, coupling, plastic cap
Pipe coating: Black vanish, bare, clear oil

Related Names
ERW Steel Pipe | ERW Steel tube