China Steel Pipe Manufacturers, Suppliers and Factory - Wholesale Steel Pipe

Your Professional Steel Pipe Supplier

Sunlion Piping Engineering Co., Ltd. is a global supplier of piping systems and structural steel modules for energy, petrochemical, offshore, nuclear, and heavy industrial projects. With over 20 years of international project experience, Sunlion delivers vertically integrated solutions from raw materials to finished modules. The company serves leading EPC contractors and end users worldwide, providing compliant products, modular fabrication, inspection coordination, and OEM/ODM customization to support efficient and reliable project execution.

STAINLESS STEEL COIL TUBE
Stainless steel coil tube are coiled or spiral-shaped tubes known for high-temperature steam resistance, impact corrosion resistance, and anti-scaling properties.
Seamless Carbon Steel Line Pipe
Manufactured from seamless carbon steel and low-alloy steels using hot-rolled or cold-drawn processes, our seamless line pipes offer high strength excellent toughness, good weldability, and corrosion
Carbon Steel Seamless Bolier Pipe
Specifically designed for high-temperature and high-pressure applications, our seamless boiler tubes are precision-manufactured from premium carbon and low-alloy steels using hot-rolled or cold-drawn
Stainless Steel Seamless Pipe
Our high-quality stainless steel seamless pipes are manufactured via advanced hot-extrusion, cold-drawn, or cold-rolled processes, offering weldless construction, dense microstructure, excellent
Offshore Structures Pipe
Specifically engineered for harsh offshore environments—including offshore oil & gas platforms, deepwater jackets, offshore wind monopiles & transition pieces, and FPSO support structures—our
Seamless Cylinder Tubes
Specifically engineered for high-pressure gas storage, our seamless cylinder tubes are manufactured from premium carbon and alloy steels via hot-rolled or cold-drawn processes. These tubes offer high
OCTG Casing
Designed for oil and gas drilling, completion, and production operations, our octg casing manufactured from high-strength carbon and alloy steels. Boasting exceptional tensile strength, collapse
Hollow Section
Our high-quality cold-formed and hot-finished hollow steel sections include square, rectangular, and circular tubes, widely used in building structures, bridges, machinery, energy facilities, and
ERW Steel Pipe
Our high-quality ERW (Electric Resistance Welded) steel pipes are crafted via advanced high-frequency welding (HFW) or contact welding technology, shaping cold-rolled steel strips into precise
LSAW Steel Pipe
Our high-quality LSAW steel pipe are manufactured from single steel plates formed via UOE, JCOE, or RBE processes, and welded longitudinally using double-sided multi-wire automatic submerged arc
Helical Welded Pipe
Our high-quality helical welded pipe are manufactured from hot-rolled steel coils or plates, formed in a spiral configuration and welded using double-sided multi-wire automatic submerged arc welding
SS Welded Pipe
Our high-quality SS welded pipe are manufactured from premium stainless steel strips or plates using High-Frequency Welding (HFW) or TIG/GTAW welding, followed by solution annealing and

why choose us

Quality Control

All products are manufactured to recognized standards such as ASME, DIN, GB, and JIS and undergo coordinated inspection and testing by third-party organizations such as SGS to ensure traceability and consistent quality.

Customization Services

We offer OEM and ODM services, tailored to project requirements, including material grades, dimensional tolerances, marking systems, packaging methods, and documentation, to meet both standardized and project-specific engineering needs.

Integrated Supply Chain

We manage the entire supply chain, from steel pipe sourcing to prefabricated piping and structural modules. This integrated model simplifies procurement coordination, improves schedule control efficiency, and minimizes interface risks between multiple suppliers in complex projects.

Sales Markets

With over two decades of experience executing international projects, we have delivered materials and modules to projects in the Middle East, Australia, the Americas, Africa, and Europe, supporting EPC general contractors under various technical standards and logistical conditions.

Specification

Specification Item	Details
Product Name	Seamless Pipe
Manufacturing Process	Hot-rolled or cold-drawn seamless ECT
Material	Carbon steel，stainless steel,Alloy steel, Nickel basis ect
Standards	API 5L, ASTM A106, ASTM A53, EN 10216, ISO 3183, GB/T 9711,, A333 ,A335, ASTM A312, EN10219,EN10210,A671,A672,A691, API 5CT,API 5B,DIN17175,DIN1629,DIN1626,BS1387 JIS G3454/3455/3456/3444/3445ECT
Steel Grades	Gr.B, X42–X70, L245–L485,S235/355/460 JR/J0/J2/K2 ,gr 3, gr6, p11, p22, p5, p9,p91,p92 ect
Outer Diameter	8 mm – 10000 mm
Wall Thickness	1 mm – 200 mm
Length	6 m, 12 m, max per joint
Surface Condition	Bare, varnished, oiled, or coated
Applications	Oil and gas pipelines, process piping, industrial fluid transport ect.

Advantages of Steel Pipe

High Durability

Capable of withstanding pressure and heavy loads in various applications.

Long Lifespan

Strong material that does not easily deteriorate, reducing maintenance costs.

Flexibility in Use

Can be adapted for various industries and operational conditions.

Environmentally Friendly

Recyclable material, supporting sustainable industry principles.

Types of Steel Pipe

Welded Steel Pipe

Manufactured using welding techniques, it has robust structure, high precision, and is more economical than other types. With optimal durability under pressure and extreme conditions, welded pipes are the primary choice in construction, water distribution, and oil & gas industries, where efficiency and reliability are essential.

Seamless Steel Pipe

A pipe made without joints, commonly used in industrial piping systems for oil and gas.

Stainless Steel Pipe

A steel pipe with specific characteristics to enhance resistance to environmental conditions, such as food and pharmaceutical industries.

Alloy Steel Pipe

A steel pipe containing additional elements designed for specific industrial applications.

Manufacture Process of Steel Pipe

Material Selection and Preparation: Choose suitable billets (usually round billets) as raw materials to prepare for subsequent processing.

Heating and Piercing: Heat the billets to the appropriate temperature, then use a piercing machine to create a hole in the center, forming a hollow tube.

Rolling and Sizing: Roll the hollow tube using methods such as three-roll skew rolling, continuous rolling, or extrusion to expand or reduce the diameter, achieving the required size and wall thickness.

Finishing: Further process the tube according to project requirements by selecting either hot finished (hot rolling, hot expansion) or cold finished (cold rolling, cold drawing) techniques to adjust the dimensions and properties of the pipe.

Heat Treatment: Perform heat treatment on the rolled pipes to improve their mechanical properties and microstructure, enhancing overall performance.

Straightening and Refining: Straighten the pipes to ensure their linearity, then carry out refining processes such as cutting and deburring to improve product quality.

Testing and Marking: Conduct hydrostatic testing or non-destructive testing on the finished pipes to ensure quality standards are met, and proceed with marking and categorization for subsequent storage and transportation.

Application Scope of Steel Pipe

Water
Because steel is both rust and corrosion proof, it is an excellent choice for the delivery of domestic water. Its strength and durability help it to last many years underground despite pressure, shock and vibration.

Construction
Many contractors and companies now use steel tubing in building foundations and framing systems. It is also used to create handrails, poles, fences, scaffolding, chimney pipes, exhaust pipes and temporary structures.

Utilities
Steel pipes are used to encase utility lines underground and for Electric power, gas lines, water mains The durability and strength of steel pipes and tubes make them an excellent choice for protecting sensitive lines.

Extreme Utilities
Steel pipes are also a great choice for extreme utilities, such as hot water lines and gas transportation. Black steel pipes are the best option in this type of situation, as they feature an iron oxide coating on the outside in addition to the strength and durability of the steel tubing on the inside.

Sewage
Because of its anti-corrosive properties, steel tubing is ideaL for underground sewage. Your best bet is to choose galvanized corrugated steel tubing for this purpose. The ripples found within the galvanized corrugated steel tubing increases its ability to handle extreme levels of pressure, which are found regularly in underground sewage systems.

Customization Services

We offer custom steel pipe manufacturing solutions to meet your project needs. The main customizable options are:

Material & Grade	Customizable
Outer Diameter	Customizable
Wall Thickness	Customizable
Length Tolerances	Customizable
Surface Treatment	Customizable
Our customization capabilities extend beyond the options listed above. Should you have additional requirements, we are able to make flexible adjustments in accordance with your specific needs and circumstances.

Packaging and Shipping

Packaging	Rust-proof paper, plastic caps, hexagonal bundling or wooden crates
Transportation methods	Road transport, rail transport, sea transport

FAQ

Q: Which standards do your seamless line pipes comply with?

A: Mainly API SPEC 5L, ASTM A106, GB/T 9711. Custom production to EN, JIS, or ASME standards is also available.

Q: What materials can you supply? Can you customize special alloys?

A: Standard grades include A106 Gr.B, L245NB, X52-X80. We support custom alloys like 12Cr1MoVG and 15CrMo upon technical agreement.

Q: Do you have classification society certifications? Can your pipes be used in offshore platforms?

A: Yes, we hold factory approval from ABS, DNV, BV, CCS, RINA, NK,etc., making our pipes suitable for offshore platforms, FPSOs, and subsea pipelines.

As one of the most professional steel pipe manufacturers and suppliers in China, we offer a wide range of products with superior quality. Please rest assured to wholesale high-grade steel pipe at competitive price from our factory. Contact us for more details.

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