The main equipment of the ERW steel pipe mill line

The efficiency and quality of welded pipe production heavily depend on the various equipment used throughout the process. Below is a detailed description of the key machinery in an Electric Resistance Welding (ERW) steel pipe mill line.

Uncoiler
This device disassembles hot-rolled steel coils and feeds them to the leveling machine. It operates using either upper or lower unwinding methods.

Steel Strip Leveling Machine
Before forming, the strip is leveled to ensure uniformity. The leveling machine typically consists of upper and lower bases along with a transmission system, featuring multiple rollers for effective leveling. Pinch rollers are commonly positioned before the leveler in welded pipe production.

Head Cutting Butt Welding Machine
To maintain continuous production, the irregular ends of steel strips are trimmed and welded together using a shear butt welder, ensuring a consistent feed for production.

Storage Looper
This device stores strip steel to facilitate uninterrupted production. It manages the transitions between cutting and butt welding by continuously supplying pre-stored strips.

Horizontal Looper
Designed for strip steel thicknesses from 0.4 to 16mm and pipe diameters of 14 to 610mm, the horizontal looper minimizes deformation and simplifies maintenance.

Disc Shears
These shears trim the edges of the strip to meet the width and straightness requirements of the forming machine, ensuring precision in the production process.

Edge Milling Machine
For strips thicker than 10mm, this machine mills the edges to achieve optimal geometry, enhancing welding quality and reducing material waste.

Forming Machine
The straight seam resistance roll forming machine shapes the steel strips into pipes.

Roller
As the primary mold for producing high-frequency welded pipes, rollers are essential components that significantly influence product quality and production costs.

High Frequency Welding Device
Utilizing the skin and proximity effects of high-frequency currents, this device rapidly heats metal to a molten state for effective welding, typically operating in the 300-450 kHz frequency range.

Sizing Machine
This unit ensures the accuracy of the steel pipe's outer diameter and cross-sectional shape, addressing any stress concentration and residual stress from prior forming and welding operations.

Internal Burr Removal
This device removes weld burrs from the interior of pipes, typically utilizing a hydraulic mechanism for efficient operation.

Weld Heat Treatment
This process normalizes the weld area, enhancing its metallurgical properties and eliminating welding stresses, typically conducted with intermediate frequency heat treatment machines.

Length Cutting Machine
This crucial equipment allows for high-precision cutting of pipes to fixed lengths, employing various cutting methods controlled by a microcomputer.

Steel Pipe Straightening Machine
To correct any curvature in the pipes, straightening machines utilize pressure or roller methods to achieve straightness.

Pipe End Flat Head Chamfering Machine
This machine trims the ends of pipes to remove defects and prepare them for subsequent processes, featuring an automatic cycle for efficiency.

Hydraulic Testing Machine
Essential for ensuring the integrity of welded pipes, this machine conducts hydrostatic tests using PLC control for precise operations and automatic result recording.

Ultrasonic Flaw Detection
This non-destructive testing method detects internal defects by analyzing ultrasonic wave diffraction at material interfaces.

Eddy Current Testing
Commonly used for small diameter pipes, this method allows for rapid online detection of surface defects, although it has limitations for internal defects.

Together, these machines create an integrated system that streamlines the production of high-quality ERW steel pipes, ensuring efficiency and reliability in the manufacturing process.