To make ERW pipe, steel coils are transformed into welded tubes through a step-by-step process. This guide covers material selection, forming, welding, and finishing steps to produce high-quality ERW steel pipes. Follow along to learn how to make ERW tube efficiently.
Table of Contents
What are ERW Pipes and Tubes
ERW pipes full form Electric Resistance Welded pipes, are a type of steel pipe manufactured using the electric resistance welding (ERW) process. This erw pipe cold formed is a flat steel strip into a cylindrical or rectangular shape and then welding the edges together using an electric current. The result is a strong, durable, and highly resistant to corrosion.
ERW pipes are widely used across various industries due to their superior properties. In the oil and gas sector, they are essential for transporting fluids under high pressure. The petrochemical industry relies on ERW tubes for their ability to handle hazardous materials safely. In construction, these pipes are valued for their strength and reliability in structural applications. The automotive and aerospace industries also utilize ERW tubes for their precision and performance in critical components.
Raw Materials for ERW tube Manufacturing process
High-quality ERW tubes start with selecting superior raw materials. Steel coils, known for their strength and durability, are the primary materials used. Commonly utilized materials include Hot Rolled (HR) Coils, Mild Steel, and Galvanized Iron, each bringing unique properties to the production process of erw steel pipe. Stainless steel pipes, known for their excellent corrosion resistance, are also highly valued in various applications.
The quality of these raw materials is crucial. Superior steel coils ensure the final product withstands its intended pressures and demands. The durability and reliability of ERW tubes heavily depend on these materials, making them a vital starting point.
Mild steel, with its carbon content of 0.3% or less, is particularly favored in the production of carbon steel ERW pipes and the erw steel pipe range, including mild steel pipe. This low carbon content enhances the structural integrity and performance of the pipes, making them suitable for a wide range of industrial uses.
Galvanized Iron Pipe (GI) is made from galvanized iron, and this layer of zinc acts as a protection against corrosion, greatly extending the life of the coated iron pipe. Galvanized steel pipes are highly resistant to corrosion, making them ideal for use in clean water supply lines.
Read this article to learn what are MS/GI/GP/ERW tubes and pipes!
Cold Rolling Processing and Slitting Machine
When we produce steel pipe, we first need to consider the wall thickness and size of the steel plate, we can choose to buy the right steel coils and produce them directly, or we can consider to start from hot rolled coils and go through cold rolling to get the right thickness of coils, and then go through the slitting machine to get the right width of coils.
Cold Rolling Mill Machine is used to continuously calender metal sheets (such as steel, aluminum, copper, etc.) through rolls at room temperature to thin their thickness and improve surface quality and mechanical properties. Through multi-pass rolling, tension control and precision adjustment of rolls, it eliminates residual stress after hot rolling and improves material strength, flatness and finish. It is suitable for the production of thin plates and precision strips, and has the advantages of high dimensional accuracy and no oxidized layer on the surface. Learn more about Cold Rolling Mill Machine.
Coil steel slitting machine are metal processing equipment used to cut metal coils along the longitudinal direction into a number of narrow-width materials. It slits wide steel coils into narrow strips of the required width through the processes of uncoiling, leveling, longitudinal shearing by multiple sets of disc knives, and rewinding, and is suitable for precision machining of materials such as stainless steel, aluminum alloy, carbon steel, and so on. Learn more about Slitting Machine.
Uncoiling and Flattening Process
The journey from raw material to finished product begins with the uncoiling and flattening of the steel coils. During uncoiling, the packaging of the incoming steel coils is removed, preparing them for subsequent steps.
The flattening process is a critical step where the steel coil is transformed into a flat strip. This step eliminates any residual curvature, ensuring a uniform steel strip ready for further processing. The coils are fed through flattening rolls, which shape them into a flat strip necessary for subsequent manufacturing steps.
Ensuring a smooth and even surface during the flattening process is crucial for the quality of the final ERW pipe product. A uniform steel strip sets the stage for effective welding and ultimately, a high-quality pipe.
Coil Joining Techniques
Once the flat steel strip is flattened, the next step is to join the coil ends to create a continuous strip. The primary method used for this purpose is butt welding, which joins the edges of the coil ends seamlessly. This technique is essential for maintaining a continuous production flow.
In some mills, tab setting is used to ensure complete edge-to-edge welds, particularly for products like coaxial cables. This technique helps in achieving precise and strong welds, which are crucial for the structural integrity of the final product.
Coil end joiners play a vital role in maintaining the flow of material without interruptions. Minimizing downtime and waste, these joiners keep the manufacturing process efficient and cost-effective. This continuous strip is then ready for further processing, leading to the creation of high-quality ERW pipes.
Edge Trimming for Precision
Precision is key in ERW tube manufacturing. The edge trimming process ensures the steel strip achieves the exact width needed for further processing, vital for effective welding and structural integrity.
Slitter blades and edge milling are the primary tools used in this process. These tools trim the strip edges to the precise width required, ensuring that the subsequent welding process can be carried out with high accuracy. This precision is crucial for the overall quality and performance of the final ERW pipes.
Strip Accumulator
This machine is used in steel tube mill production lines, between the shear welder and the forming section, and its role is to store enough strip to ensure the continuation of the production of subsequent equipment.
Cage Strip Accumulator
Horizontal Loop Accumulator
Landed Spiral Loop Accumulator
There are three common types of cages, the Cage Strip Accumulator, the Horizontal Loop Accumulator and the Landed Spiral Loop Accumulator. know more about strip accumulator.
Forming, High Frequency Resistance Welding and Sizing Process
As the core equipment of the steel tube mill production line, the forming, high-frequency welding and sizing machine is responsible for processing the steel strip into round or rectangular shape, and then heated up by high-frequency resistance welding to bond the edges of the strip to form a solid weld. Then it passes through the cooling water tank and enters the sizing station to get the pipe that meets the precise specification.
Forming section in pipe mill machine
The forming station is used for bending metal strips into specific cross-sectional shapes (e.g. round, square, etc.) by means of a multi-roll press. The strip is continuously molded by precision roll sets to form a closed pipe shape in preparation for subsequent high-frequency welding.
General pipe forming has two kinds of round to square tube and directly into a square tube, round to square refers to the forming section of the strip rolled into a round shape and then rolled into a square by the sizing station, directly into a square refers to the forming section directly rolled into a square.
High Frequency Induction Electric Resistance Welding
High-frequency induction welding, a state-of-the-art technology, is used for manufacturing ERW pipes up to a 21-inch diameter. The tube mill machine plays a crucial role in this process, facilitating the production of various types of steel pipes, including ERW and stainless steel pipes. Welding current is transmitted through a work coil without contact, heating and bonding the edges of the steel strip to form a welded joint. The high-frequency electrical currents generate the necessary heat to bond the edges of the steel strip without the need for filler material, resulting in a clean and strong weld. This method has largely replaced low-frequency welding methods due to its efficiency and effectiveness.
A significant advantage of high-frequency induction welding is the elimination of contact marks and reduced setup time for size changes, enhancing overall manufacturing efficiency. Monitoring the welding process is essential to detect any defects and ensure proper seam integrity, ensuring that the final product meets the highest standards.
Clamp systems ensure proper alignment and heat management during welding. This precise control is vital for producing high-quality ERW tubes with consistent welds. This article details the High Frequency welding.
Sizing and Straightening the Pipe
The sizing process ensures the welded pipe meets specific tolerances for roundness, diameter, and straightness, critical for performance in various applications.
Post-welding, the pipe undergoes sizing to ensure it meets precise specifications for roundness, outer diameter, and straightness. Dimensional inspections are performed to verify that the dimensions of the pipes meet specified standards.
Ensuring the pipe meets these precise specifications is crucial for its performance and reliability. This step is essential for producing high-quality ERW pipes that meet industry demands.
Cutting the Pipe to Desired Lengths
After sizing and straightening, the next step is to cut the pipes and tubes to the desired lengths. This is achieved using a flying cut-off saw, which enables continuous cutting of pipes without interrupting the production line.
Flying cut-off saws cut the sized pipe to required lengths post-sizing, contributing to higher production speeds with fast and accurate cuts, ensuring manufacturing efficiency.
Accurate cuts meet customer specifications and ensure the pipes are ready for their intended applications, vital for maintaining the final product’s quality and consistency.
Flying saws include cold and hot saws, read this article to learn more about flying saws
Palletizers in Steel Tube Mill Line
Palletizers are the most important part of the tube packaging process, designed to automatically stack tubes onto pallets, according to the shape and size of the tubes into a variety of stacks suitable for storage and transportation, such as square bales, hexagonal bales and so on.
There are many different models of palletizers with different footprints and prices, so read this article to help you better choose the right palletizer for you!
Quality Control Measures
Quality control is crucial in ERW pipe manufacturing, ensuring compliance with industry standards essential for safety and performance. High quality maintains the manufacturer’s reputation and attracts repeat customers.
Non-destructive testing methods, like ultrasonic and X-ray testing, identify flaws without causing damage, ensuring the pipes meet the highest standards of quality and reliability.
Advantages of ERW Pipes
ERW pipes offer several advantages over other types of pipes, making them a preferred choice in many applications:
Higher Strength-to-Weight Ratio: ERW pipes boast a higher strength-to-weight ratio compared to seamless steel pipes. This makes them ideal for applications where weight is a critical factor, such as in the automotive and aerospace industries.
Lower Production Cost: The ERW manufacturing process is faster and more efficient than the seamless pipe process. This efficiency translates to lower production costs, making ERW pipes a cost-effective solution for many industries.
Improved Dimensional Accuracy: ERW tubes are known for their high dimensional accuracy. This precision is crucial in applications where exact measurements are required, ensuring a perfect fit and optimal performance.
Wide Range of Sizes: ERW tubes are available in a broad range of sizes, from 2 3/8 inches to 24 inches in diameter. This versatility allows them to meet the diverse needs of different industries and applications.
Corrosion Resistance: ERW pipes can be coated with various materials, such as zinc, epoxy, and polyethylene, to enhance their resistance to corrosion. This makes them suitable for use in harsh environments where corrosion is a concern.
Applications of ERW Pipes
ERW pipes are indispensable in numerous industries due to their versatility and robust performance:
Oil and Gas: In the oil and gas industry, ERW pipes are used for transporting oil, gas, and other fluids. Their high strength and corrosion resistance make them ideal for withstanding the harsh conditions of this sector.
Petrochemical: The petrochemical industry utilizes ERW tubes for the safe transportation of chemicals and other hazardous materials. Their durability and reliability are crucial for maintaining safety standards.
Construction: ERW tubes are widely used in construction for transporting water, gas, and other fluids. They are also employed in structural applications due to their strength and stability.
Automotive: In the automotive industry, ERW pipes are used in the manufacture of exhaust systems, fuel lines, and other critical components. Their precision and strength ensure the reliability and performance of these parts.
Aerospace: The aerospace industry relies on ERW tubes for the manufacture of aircraft and spacecraft components. Their high strength-to-weight ratio and dimensional accuracy are essential for the demanding requirements of this sector.
By understanding the manufacturing process, advantages, and applications of ERW pipes, one can appreciate their critical role in various industries and the importance of each step in ensuring the final product meets the highest standards.
Summary
In summary, the manufacturing process of ERW tubes is a meticulous journey that involves several critical steps, each contributing to the final product’s quality and reliability. From selecting high-quality raw materials to precise cutting and stringent quality control measures, every aspect of the process is designed to produce robust and durable ERW tubes.
New Victor Tube Mills is a manufacturer specializing in erw steel tube mill production line for 30 years. The company has 1 8 patented inventions in the welded pipe industry and exports more than 500 production lines worldwide to more than 70 countries. providing one-stop service for plant design, equipment production and after-sales installation, contact us to start your successful project!
Frequently Asked Questions
What raw materials are essential for ERW pipe manufacturing?
Steel coils, Hot Rolled (HR) Coils, Mild Steel, and Galvanized Iron are essential raw materials for ERW pipe manufacturing. These materials ensure the structural integrity and durability of the finished pipes.
Why is the flattening process important in ERW steel tube manufacturing?
The flattening process is crucial in ERW tube manufacturing as it removes any residual curvature from the steel coils, ensuring a uniform steel strip essential for the subsequent manufacturing steps. This uniformity directly contributes to the quality and integrity of the finished pipes.
What is high-frequency induction welding?
High-frequency induction welding is the process of transmitting welding current through a work coil to seamlessly bond the edges of a steel strip without the need for filler material, resulting in a strong and clean weld. This technique is efficient and widely used in various applications.
How are carbon steel pipe cutting machine work?
ERW tubes are efficiently cut to the desired lengths using flying cut-off saws, allowing for continuous operation without halting production. This method ensures precise and timely cutting.
What quality control measures are taken in ERW pipe manufacturing?
Quality control in ERW pipe manufacturing includes non-destructive testing methods such as ultrasonic and X-ray testing to detect any flaws, along with the utilization of high-quality steel coils to reduce corrosion and enhance the pipes’ durability.