Large Diameter Spiral Welded Steel Pipe

Large Diameter Spiral Welded Steel Pipe is produced by using hot rolled steel strips as raw materials. Through continuous spiral forming, internal and external double-sided submerged arc welding, non-destructive testing, and hydraulic pressure testing, the steel strip is transformed into a large diameter welded steel pipe.

The product is mainly designed for projects requiring large transportation capacity, long-distance pipeline installation, and large diameter structural applications.

In the steel pipe industry, outer diameter ≥820mm (DN800) is generally considered large diameter. Pipes with diameter φ1420mm and above are commonly classified as ultra-large diameter steel pipes.

The key features of Large Diameter SSAW Steel Pipe include large diameter manufacturing capability, balanced stress distribution, strong deformation resistance, high transportation efficiency, and suitability for large-scale engineering projects.

Technical Specifications

Advantages of Large Diameter SSAW Steel Pipe

1. Outstanding Ultra-Large Diameter Manufacturing Capability

The biggest advantage of Large Diameter Spiral Welded Steel Pipe is its ability to achieve large diameter production through spiral welding technology.

Compared with seamless steel pipes and some straight seam welded pipes, spiral welded steel pipe manufacturing is less restricted by diameter limitations. It can achieve stable production of pipes above φ3000mm, making it an ideal choice for large-scale water transmission, municipal pipeline networks, and industrial projects.

ZHONGTIAN provides customized large diameter steel pipe solutions according to project requirements, including diameter, wall thickness, material grade, and coating options.

2. High Transportation Efficiency for Large Flow Systems

Large diameter pipeline systems are usually designed for transporting large volumes of water, gas, or industrial fluids.

Large Diameter SSAW Steel Pipe provides a larger internal flow area, reducing flow resistance and improving transportation efficiency. For long-distance transmission projects, increasing pipe diameter can reduce the number of parallel pipelines required and optimize overall engineering investment.

3. Stable Structural Performance Under Complex Conditions

Large diameter pipelines may experience external pressure, soil movement, and installation stress during service.

The spiral welded structure helps distribute stress evenly along the pipe body, improving resistance against deformation, foundation settlement, and external loads. This makes Large Diameter Spiral Welded Steel Pipe suitable for buried pipelines and complex geological environments.

4. Reduced Field Welding and Faster Construction

For long-distance pipeline projects, the number of field joints directly affects construction efficiency and operating reliability.

Large Diameter Spiral Welded Steel Pipe can be supplied in longer standard lengths, commonly 12 meters, with customized lengths available according to project requirements. Longer pipe sections reduce field welding points, shorten construction periods, and reduce potential leakage risks.

5. Better Economic Performance for Large Projects

Large diameter engineering projects require comprehensive consideration of material cost, transportation cost, and installation efficiency.

Compared with large diameter seamless steel pipes and some straight seam pipes, Large Diameter SSAW Steel Pipe provides better cost performance while maintaining required mechanical performance, making it widely selected for large infrastructure projects.

6. Flexible Material and Wall Thickness Selection

Different engineering environments require different pipe performance levels.

ZHONGTIAN can supply Large Diameter Spiral Welded Steel Pipe with different material grades and wall thickness combinations, allowing customers to select suitable solutions according to pressure requirements, soil conditions, transportation medium, and service environment.

Main Applications

1. Large Municipal Pipeline Networks

Large Diameter Spiral Welded Steel Pipe is widely used in urban water supply systems, drainage trunk pipelines, sewage transportation networks, rainwater collection systems, and city water transfer projects.

Its large flow capacity and economical construction characteristics make it suitable for major municipal infrastructure projects requiring long-term operation and stable performance.

2. Water Conservancy and Hydraulic Engineering

Large-scale water conservancy projects require pipelines with high transportation capacity and reliable structural performance.

Large Diameter SSAW Steel Pipe is commonly applied in reservoir connection pipelines, pumping station pressure pipelines, flood control systems, river crossing pipelines, and large water diversion projects.

3. Oil and Gas Long-Distance Transportation

For crude oil, natural gas, refined oil transportation, and oilfield gathering systems, large diameter pipelines help improve transportation efficiency.

According to project pressure requirements and international pipeline standards, materials such as L245, L360, X52, X60, and X70 can be selected to meet different pipeline conditions.

4. Large Diameter Pile Foundation and Support Engineering

Due to its large size and structural stability, Large Diameter Spiral Welded Steel Pipe can be used in bridge foundations, port construction, high-rise buildings, large diameter pile casings, and temporary support structures.

It provides reliable support capability and is suitable for projects requiring large diameter foundation components.

5. Industrial Ventilation and Process Pipelines

Large diameter spiral welded pipes are also used in industrial ventilation systems, dust removal pipelines, power plant cooling water systems, chemical plant circulation pipelines, and industrial process transportation systems.

The large diameter design helps improve transportation capacity and supports efficient industrial operation.

6. Underground Utility Corridors and Tunnel Projects

In underground engineering, Large Diameter SSAW Steel Pipe can be used for comprehensive utility corridors, tunnel pipeline systems, and underground transportation applications.

Its large diameter capability helps improve pipeline integration and optimize underground space utilization.

Manufacturing Process

1. Steel Strip Preparation

Production begins with hot rolled steel strips selected according to required diameter, wall thickness, and material grade.

The steel strips are uncoiled, leveled, and edge processed to ensure accurate forming dimensions and stable welding conditions.

2. Spiral Forming Control

The prepared steel strip is continuously formed into a spiral pipe shape under controlled production parameters.

During this process, pipe roundness, diameter accuracy, and forming stability are carefully controlled to ensure reliable finished products.

3. Double-Sided Submerged Arc Welding

The internal and external spiral seams are welded using double-sided submerged arc welding technology.

This welding method provides stable weld penetration, reliable connection strength, and consistent mechanical performance for large diameter pipeline applications.

4. Inspection and Surface Treatment

After welding, each pipe undergoes strict inspection procedures, including ultrasonic testing, X-ray inspection, dimensional inspection, and hydraulic pressure testing.

According to customer requirements, pipes can be supplied with end beveling, surface treatment, and anti-corrosion coatings before shipment.

Anti-Corrosion Protection and Service Life

1. Underground Water and Municipal Pipelines

For ordinary buried water supply and drainage projects, Large Diameter Spiral Welded Steel Pipe can use epoxy coal tar coating or IPN8710 anti-corrosion coating.

Under suitable installation conditions, the service life can generally reach 15–20 years depending on soil environment and maintenance conditions.

2. Long-Distance Transmission Pipelines

For high-standard oil, gas, and water transmission projects, 3PE three-layer polyethylene coating is commonly selected.

This coating system provides excellent resistance against moisture, soil corrosion, and external damage, with a service life of more than 30 years under suitable conditions.

3. Outdoor and Industrial Applications

For outdoor pipelines, ventilation systems, and steel structures, anti-rust primer combined with surface paint can provide effective atmospheric corrosion protection.

The expected service life is generally around 10–15 years depending on environmental conditions.

4. Temporary Foundation Applications

For temporary pile casing and short-term construction applications, simple rust removal and painting treatment may be sufficient.

The protection method can be selected according to the project duration and actual environmental requirements.

Selection Guide

1. Select Diameter According to Flow Requirements

The diameter selection of Large Diameter Spiral Welded Steel Pipe should be based on required transportation capacity, flow rate, and system design.

For large flow applications, DN800 and above large diameter steel pipes are generally selected to improve transportation efficiency and reduce pipeline quantity.

2. Match Wall Thickness With Pressure and Installation Conditions

Higher working pressure, deeper burial depth, and more complicated geological conditions require thicker wall thickness.

The appropriate wall thickness should be selected according to engineering calculation rather than simply choosing the thickest option.

3. Choose Material According to Application

For general low-pressure municipal projects, Q235B is commonly selected.

For medium and high-strength applications, Q355B is suitable. For oil and gas transmission pipelines, L245, L360, X52, X60, and X70 pipeline steels are selected according to required standards.

4. Consider Corrosion Environment

For coastal areas, salt environments, and corrosive media transportation systems, higher-level anti-corrosion protection should be selected.

Proper coating selection helps extend service life and reduce maintenance requirements.

5. Optimize Pipe Length for Construction Efficiency

For long-distance pipeline projects, longer pipe sections can reduce field welding points.

ZHONGTIAN can provide customized pipe lengths according to transportation conditions and construction requirements.

Why Choose ZHONGTIAN Large Diameter Spiral Welded Steel Pipe?

1. Professional Large Diameter Pipe Manufacturing Capability

ZHONGTIAN is a professional Large Diameter Spiral Welded Steel Pipe manufacturer and supplier in China, specializing in large diameter SSAW steel pipe production.

With advanced spiral welding technology and flexible manufacturing capability, ZHONGTIAN supports customers with customized solutions for infrastructure, industrial, and energy projects.

2. Customized Engineering Solutions

ZHONGTIAN provides customized solutions covering diameter, wall thickness, material grade, pipe length, and anti-corrosion treatment.

This allows customers to select suitable large diameter steel pipe products for different operating environments.

3. Strict Quality Control System

From raw material inspection to finished pipe testing, ZHONGTIAN applies strict quality management procedures.

Through ultrasonic testing, X-ray inspection, hydraulic testing, and dimensional inspection, every pipe is manufactured to achieve stable quality and reliable performance.

FAQ

1. What Is the Difference Between Large Diameter Spiral Pipe and Large Diameter Straight Seam Pipe?

Large Diameter Spiral Welded Steel Pipe is mainly selected for long-distance pipelines, buried projects, and large flow transportation systems because of its flexible diameter manufacturing capability and cost advantages.

Large diameter straight seam pipes may have advantages in some applications requiring high dimensional accuracy or specific engineering conditions. The selection should depend on project requirements.

2. Can Large Diameter Spiral Welded Steel Pipe Be Used Above Ground?

Yes. Large Diameter SSAW Steel Pipe can be used for above-ground applications when suitable support structures are designed. Because large diameter pipes have considerable weight, support spacing, load calculation, and installation methods should follow engineering design requirements to prevent deformation.

3. What Is the Maximum Diameter of Large Diameter Spiral Welded Steel Pipe?

ZHONGTIAN can commonly manufacture Large Diameter Spiral Welded Steel Pipe up to φ3620mm (DN3600). For special engineering requirements, customized larger diameter specifications can be discussed according to project conditions.