Welded Steel Pipe

Why Choose Us

Factory Strength

Shanghai KEK Pipeline Technology Co., Ltd. is a reputable AAA listed pipe fittings manufacturer in China, covering an area of 66666㎡ (80000+㎡ in Phase II), with more than 30 technicians and engineers.

Our Certifications

KEK has obtained ISO9001, ISO14001, ISO18001, CE/PED, API certification and TS pressure pipe component special equipment manufacturing license, as well as Russia's EAC continuous certification.

Advanced Equipment

It has a full set of the largest and most advanced equipment in China, including a 4000-ton hydraulic press and a 3000-ton three-way cold extrusion molding machine.

Product Traceability

Product traceability, all products are numbered and indexed by furnace number, production process number, and RT inspection number to ensure the unique traceability of the product.

What is Welded Steel Pipe

Welded steel pipe is created using a flat steel plate or steel strip, and its manufacturing process results in a seam on its body. Specifically, when welded steel pipe is manufactured, a steel plate or strip is bent and subsequently welded into either a circular, traditional pipe shape or a square shape. LSAW pipe, SSAW pipe, and ERW pipe are all types of welded steel pipe that are categorized based on how they are welded. For instance, LSAW pipe is welded longitudinally, and SSAW pipe is spiral-welded. ERW pipe is electric resistance welded, which results in a seam that runs parallel along the pipe body.

EFW Stainless Steel Pipe
Product Name: EFW stainless steel pipe
Dimension and Wall Thickness：
Seamless: 1/2”~24” (DN15~DN600) SCH5~SCH XXS
End connection：PE or BE
Marking： according to...
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Stainless Steel Welded Tubes
Product Name: stainless steel welded tubes
Dimension and Wall Thickness
Seamless: 1/2”~24” (DN15~DN600) SCH5~SCH XXS
End connection：PE or BE
Marking： according to...
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ERW Carbon Steel Pipes
Product Name: ERW Carbon Steel pipes
Dimension and Wall Thickness
Seamless: 1/2”~24” (DN15~DN600) SCH5~SCH XXS
End connection：PE or BE
Marking： according to customer’s...
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LSAW Carbon Pipes
Product Name: LSAW carbon pipes
Dimension and Wall Thickness
Seamless: 1/2”~24” (DN15~DN600) SCH5~SCH XXS
End connection：PE or BE
Marking： according to customer’s...
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X70 Welded Pipes
Product Name: X70 welded pipes
Dimension and Wall Thickness
Seamless: 1/2”~24” (DN15~DN600) SCH5~SCH XXS
End connection：PE or BE
Marking： according to customer’s...
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Benefits of Welded Steel Pipe

01/

High efficiency and energy saving
The process of welding steel pipes utilises advanced technology and materials, resulting in high efficiency and low energy consumption. This makes it a cost-effective and energy-efficient alternative to traditional pipes. Furthermore, welded steel pipes can be customised in terms of specifications and length, making them more convenient for transportation and installation.

02/

Excellent mechanical properties
Welded steel pipes have thicker walls, higher strength, and stiffness, and can withstand greater pressure and impact. They also possess excellent mechanical properties, making them suitable for use in various complex terrains and environments, such as mountains, rivers, and bridges.

03/

Good corrosion resistance
Welded steel pipes are treated to enhance their corrosion resistance. They can operate stably for extended periods in corrosive media such as acids, alkalis, and salts, ensuring pipeline safety and longevity.

04/

Reusable
Welded steel pipes have thicker walls and can be reused after inspection and treatment, reducing costs, resource waste, and environmental pollution.

05/

Environmental protection and health
No harmful substances or odours are produced during the production and use of welded steel pipes. Additionally, their good corrosion resistance reduces the need for pipeline cleaning and maintenance, resulting in a reduced impact on the environment.

06/

Wide range of application
Welded steel pipes are versatile and can be used in various industries, including construction, petroleum, chemical, light industry, and machinery. Their excellent mechanical properties and corrosion resistance allow them to operate reliably in diverse environments.

Types of Welded Steel Pipe

Resistance welded steel pipe

Resistance welded steel Pipe, English name ERW (Electric resistance Pipe), the weld type is straight seam. Resistance welding adopts the pressure welding method without filling metal, and no other components are filled in the welding seam. By relying on the skin effect and proximity effect of high frequency current, the edge of the plate is heated to the welding temperature instantly, and the welding seam with forged structure is formed by extrusion roller.

Spiral welded steel pipe

Spiral welded steel pipe, SSAW English name (Spiral submerged - arc welding pipe, weld type is Spiral seam. Using submerged arc welding, internal and external double welding. Submerged arc welding (including submerged arc surfacing and electroslag surfacing) is an important welding method, which has the inherent advantages of stable welding quality, high welding productivity, no arc light and little smoke.

Straight seam welded steel pipe

Straight seam Welded steel Pipe, LSAW English name (Longitudinally Submerged Arc Welded Pipe), the type is straight seam welding seam. The same method of submerged arc welding, internal and external double welding. The straight seam steel tube manufacture wall thickness is big, USES and the spiral welded steel tube similar.According to the different forming processes, the direct-seam welded pipe can be divided into two types: UOE(Uing and Oing forming pipe) and JCOE (j-ing, c-ing and o-ing pipe). UOE forming method (U forming, O forming, E expanding), JCOE forming method (steel plate is pressed into J type, then pressed into C type and O type successively, and then expanded).

Application of Welded Steel Pipe

Water and Gas Transport

Welded steel pipe is excellent for transporting water, other fluids, and natural gas. Its affordable price makes it ideal for large-scale projects.

Pipe Casing

When drilled shafts are constructed, pipe casing (whether temporary or permanent) is needed, and welded steel pipe can be used for this purpose. When used as pipe casing, welded steel pipe adds support to a hole while construction in progress.

Bearing Piles

Welded steel pipe can be driven into the ground to help support and carry loads from big, heavy structures. When used as bearing piles, welded steel pipe may also be filled with concrete to boost strength.

Combi Walls

Welded steel pipe can be employed in the creation of combi walls, which serve as retaining structures. In combi walls, welded steel pipe is the king pile that is used in concert with steel sheet piles to form a strong, durable structure that can support significant loads.

Underground Utilities

Bored and jacked welded steel pipe can be used to assist when underground utilities are installed. When employed this way, hydraulic jacks drive sections of steel pipe between excavations, which are then conjoined with other sections of spliced pipe. Once the desired pipe structure is created, it is cleared and cleaned out to allow for a safe area for utility work.

Seamless vs welded steel pipe differences summary

Appearance difference
Seamless steel pipe used steel billet as raw material. The outer surface defects of billet cannot be eliminated by hot rolling process, it is only polished after the product finished. In the process of wall reduction, the defect can only get partially eliminated.Welded steel pipe made by hot rolled coil as raw material, the surface quality of coil is just the pipe’s surface quality, and easy to control.The surface of hot rolled coil have high quality.So Welded steel pipe surface quality is much better than seamless steel pipe.

Molding process differences
Seamless steel pipe can be formed one time in the rolling process.
Welded steel pipe is manufacturing with steel strip or steel plate, through bending and different welding processes.

Performance and Usage
Seamless steel pipe has better pressure capacity, strength is higher than ERW welded steel pipe. So it is widely applied in high pressure equipment, and thermal, boiler industries.Generally the welding seam of the welded steel pipe is the weak point, the quality affect overall performance.In general, welded steel pipes can withhold 20% less working pressure than seamless ones. This reliability is the prime factor why people go for seamless steel pipe. As a matter of fact, all the industrial pipelines are done with seamless pipes only because the pipes undergo extreme thermal, chemical and mechanical workloads. Welded pipes are more preferred in aerospace, automobile and electronics industries where the budget is comparatively low, and so is the work pressure put on the pipes.

Available Sizes differences
For most of seamless steel pipe manufacturers in China, they produce original seamless pipe sizes maximum OD in 20 inch, 508 mm. Where usually is smaller than 16 inch, 406.4 mm, because of the equipment limits. And if client would like to purchase the seamless steel pipe more than above sizes, then hot expanding machining shall be used. But usually this kind hot expanded seamless steel pipe quality could not compare with the original seamless steel pipe.
On the contrary, welded steel pipe don’t have these limitations, sizes available from 1-1/2 inch 48.3mm to 100 inch 2540 mm.

How to Choose Welded Steel Pipe

Identify Your Requirements
Determine the specific requirements for your project or application. Consider factors such as the intended use, working pressure, temperature, fluid/gas being transported, and any other special considerations.

Material Grade
Select the appropriate material grade based on your requirements. Different grades of steel offer varying levels of strength, corrosion resistance, and other properties. Common grades include ASTM A53, ASTM A106, API 5L, and others.

Pipe Size and Dimensions
Determine the required size, outer diameter (OD), wall thickness, and length of the pipe. Ensure that the dimensions match your project's specifications and are compatible with other components in the system.

Welding Method
Consider the welding method used to manufacture the pipe. Welding techniques for common welded pipes include ERW pipe (resistance welding), SAW pipe (submerged arc welding) and LSAW pipe (longitudinal submerged arc welding) Each method has its advantages and disadvantages, so choose the one suitable for your application.

Quality and Standards
Look for welded steel pipes that comply with relevant industry standards and specifications. Check if the manufacturer holds certifications such as ISO 9001, API 5L, or other quality assurance standards.

Corrosion Resistance
If your application involves exposure to corrosive environments, consider pipes with additional corrosion-resistant coatings or materials, such as galvanized pipes or stainless steel pipes.

Supplier Reputation
Choose a reputable and reliable supplier with a proven track record in providing high-quality welded steel pipes. Look for customer reviews, testimonials, and industry reputation.

Price and Budget
Compare prices from different suppliers, but avoid compromising on quality for the sake of lower costs. Consider the overall value and long-term performance of the pipes rather than just the upfront cost.

Technical Support
Ensure that the supplier provides adequate technical support and assistance, especially if you have specific technical queries or custom requirements.

Shipping and Delivery
If the supplier is located far from your location, consider the shipping and delivery options, as well as any associated costs and delivery times.

Process of Welded Steel Pipe

Material Preparation

The first step in the welded steel pipe manufacturing process is material preparation. Raw materials such as steel coils inspect for defects and surface imperfections. The steel strips are then fed through a series of rollers to achieve the desired thickness and width.

Forming

Once the steel strips have been prepared, they are shaped into pipes through various forming methods. One of the most common methods is the ERW (Electric Resistance Welding) process. Where the steel strips pass through a series of rollers and then can weld together using an electric current. Another method is the SSAW (Spiral Submerged Arc Welding) process, where the steel strips are formed into a spiral shape and then welded together using a submerged arc welding process.

Welding

After the pipes form, they welding together to create a continuous length of pipe. The welding process is critical as it determines the strength and durability of the final product. The welding method used depends on the pipe size and application. In addition to the ERW and SSAW methods, other welding methods such as the LSAW (Longitudinal Submerged Arc Welding) and HFW (High-Frequency Welding) methods may be used.

Finishing

Once the pipes can weld together, They undergo finishing processes such as straightening, cutting, and inspection. The pipes straightening to ensure that they are in their proper shape and alignment. The pipes may also undergo additional finishing processes such as coating or galvanizing, depending to meet their application.

How to Maintain Welded Steel Pipe

Routine Inspection
Regular visual inspections are essential for identifying signs of corrosion, leaks, or damage. Trained personnel should conduct thorough inspections to detect any abnormalities or potential issues promptly.

Cleaning and Degreasing
Cleaning stainless steel welded pipes with a mild detergent and water solution helps remove dirt, grease, and contaminants that can accelerate corrosion. Avoid abrasive cleaners or steel brushes, as they may scratch the surface and compromise the protective oxide layer.

Passivation
Passivation, a chemical process, removes free iron from the surface of stainless steel, forming a protective oxide layer. This process enhances corrosion resistance and ensures long-term performance, particularly in harsh environments. Passivation should be performed by qualified professionals using specialized equipment and chemicals.

Repair and Maintenance
Address any identified issues or damages promptly to prevent further deterioration. Repair or replace damaged components, such as seals or support brackets, to maintain system integrity. Regular lubrication of moving parts, such as valves and hinges, helps prevent friction and wear.

Corrosion Protection
Applying a corrosion-resistant coating or lining to stainless steel welded pipes provides additional protection, especially in aggressive environments or high-temperature applications. Epoxy, polyurethane, or ceramic coatings can be applied to suit specific requirements.

Avoid Harsh Chemicals
Refrain from using harsh chemicals or acidic cleaners near stainless steel welded pipes, as they can damage the surface and compromise corrosion resistance. Stick to approved cleaning agents and follow manufacturer recommendations.

Proper Handling and Storage
Handle stainless steel welded pipes carefully to prevent scratches, dents, or deformation. Store pipes in a clean, dry environment away from moisture, humidity, and corrosive substances. Use appropriate lifting equipment and protective covers during transportation and storage.

Temperature Control
Maintain proper temperature control in areas where stainless steel welded pipes are installed to prevent thermal expansion and contraction, which can stress the pipes and lead to premature failure. Insulate pipes in cold environments to prevent freezing and condensation buildup.

Regular Testing and Monitoring
Periodically test and monitor the performance of stainless steel welded pipes using non-destructive testing methods, such as ultrasonic testing or pressure testing. Early identification of potential issues allows for timely intervention and corrective action.

Our Factory

Shanghai KAIKE Pipe Technology Co., Ltd. is a reputable AAA listed pipe fittings manufacturer in China,covering an area of 66666㎡ (80000+ ㎡in stage II) and with technician and engineers more than 30 personal. Kaike Group is made up of Shanghai Kaike Piping Technology, Shanghai Kaike Valve manufacture and one export company Shanghai Chainmill Industry, they are all based in Shanghai, which the economic center of China. KAIKE has reached up to an annual output of pipe fittings of 20,000 tons.KAIKE has the ability to produce by various materials like carbon (low temperature) steel, stainless steel, duplex steel, alloy steel, nickel base alloy and special materials as requested according to GB, SH, Hg, JB, SY, ASME/ANSI, MSS, JIS, DIN, BS,GOST etc.Its main products include BW pipe fittings(SMLS or welded), steel flange, forged pipe fittings as well as prefabricated spools and manifolds,and also can produce according to customers' drawings and requirements.

Certificate

FAQ

Q: What is a welded steel pipe?

A: A seamless steel pipe has no seams, as the name indicates and produced via hot rolling and cold rolling. A welded pipe, on the other hand, is made by rolling of a steel coil to the required gauge thickness, a manufacturing procedure that leaves a seam on the pipe's body.

Q: What is the difference between seamless and welded steel pipes?

A: Welded pipes are typically lighter than seamless pipes. They also have tighter tolerances and are consistent in wall thickness, unlike seamless pipes which are not always consistent. Many innovations in the industry have also strengthened the weld joint more than what is historically known.

Q: Is welded pipe cheaper than seamless?

A: Welded piping (which is generally cheaper to produce and is more widely available) is specified across all industries as long as the temperature, pressure and other service variables do not exceed parameters noted in the applicable standard.

Q: Which is better, seamless or ERW pipe?

A: In order to achieve weld of the highest quality, a high frequency ERW process is considered to be the most commercially viable option. Unlike welded pipes, the procedure to manufacture Seamless pipes is longer and more intensive. This process uses heat and several other operations to achieve the final product.

Q: What are the benefits of welded pipe?

A: Welded pipes have excellent corrosion resistance and can resist the erosion of chemicals and corrosive media in oil and gas. In addition, the connection performance of welded pipes is excellent, able to withstand a large amount of mechanical stress, ensuring the reliability and safety of the pipeline system.

Q: Is Schedule 40 steel pipe seamless?

A: Seamless pipe is a special kind of steel pipe, and schedule 40 is one of the specifications of seamless pipe. Seamless pipe/tubing is a steel pipe made by billet heating, perforation, rolling and cooling. Compared with welded steel pipes, seamless pipes have obvious advantages in appearance and performance.

Q: What is seamless steel pipe used for?

A: Seamless steel pipe is regularly used in the transportation of fluids such as water, natural gas, waste and air. It is also regularly required in many high-pressure, high-corrosive environments such as in the oil & gas, power generation and pharmaceutical industries.

Q: What is the cheapest type of steel pipe?

A: Carbon steel
As mentioned above, pipes that are made of carbon steel are such an economical choice since they are often ranked as the most inexpensive type of steel pipe for sale in the global market. Thanks to their durability, carbon steel pipes can help you save a lot of money needed for repairs or replacement.

Q: Why is seamless pipe so expensive?

A: Different prices:ERW is a high-frequency welded pipe, which is made of strip steel and has a lower cost. The seamless steel pipe is made by heating and perforating a tube blank. The production process is more complicated and the cost is higher!

Q: How to tell if a pipe is seamless?

A: Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length.

Q: Why must the ends of pipe be beveled before being welded?

A: Bevelling pipe ends helps to ensure that these welds are as strong as possible but it can be slow and hold up production when time is critical. Both speed and quality are important – bevelling must take place rapidly so that bottlenecks do not occur, yet it must meet high specifications to ensure welds are strong.

Q: Is seamless pipe stronger than welded?

A: Strength— Seamless pipe not having a seam means one less vulnerability. Typically, it can handle up to 20% more constant pressure than welded pipe. This is crucial in high-risk environments such as oil & gas facilities where pressure is consistently high.

Q: What are the 3 grades of steel pipe?

A: Both ASTM and ASME use grades of A, B, and C when designating pipes. These grades indicate certain properties of steel, based on their chemical makeup and resulting mechanical properties.

Q: Which grade steel pipe is best?

A: A53 pipe is best suited for transport of air, water, steam and oil in low- and medium pressure applications across the industrial spectrum. It's also commonly used as structural steel. A106 pipe is formulated specifically for high-temperature and high-pressure service, usually in power generation applications.

Q: What are some uses for welded pipe?

A: Straight seam welded steel pipe is mainly used in water supply engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation and urban construction. For liquid transportation: water supply and drainage. For gas transportation: gas, steam, liquefied petroleum gas.

Q: Is seamless pipe more expensive than welded?

A: Welded tube is almost always the more affordable option of the two, and this is largely because the costs and time needed to manufacture welded tube simply is far less than those required for seamless tube.Steel pipe offers better resistance than cast iron for internal pressure, but it fails under heavy external pressure. Steel are more Tougher and elastic than cast iron. More susceptible to corrosion.

Q: When did they stop using steel pipes?

A: Galvanized piping was created to replace the old lead piping used for home water supply lines. Many homes built before the 1960s used galvanized steel pipes for indoor plumbing. Some galvanized plumbing was still being installed as late as the 1980s.

Q: What are steel pipes welded by?

A: It is then made into a pipe by stretching the steel out into a seamless tube or forcing the edges together and sealing them with a weld. Generally small thickness and small diameter pipe are welded by high frequency induction welding and higher thickness and higher diameter pipes by submerged ac welding process.

Q: What is the difference between seamless steel and welded steel?

A: The main difference between seamless pipes and welded pipes is in the way they were manufactured. To put it simply, seamless pipes are single pieces of metal with no seam or crease, or weld joint. Welded pipes are metal products that start as a strip that would be roll-formed and then welded to form a tube.

Q: Why is pipe welding difficult?

A: Is Pipe Welding Difficult? Pipe welding is often more challenging than other types of welding and requires a higher level of welder skill. This can be due to the working conditions as well as factors such as the travel angle of the weld, the pipe position and the diameter of the pipe.

We're professional welded steel pipe manufacturers and suppliers in China, specialized in providing high quality customized service. We warmly welcome you to wholesale high-grade welded steel pipe at low price from our factory. Contact us for cheap products.

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