SSAW Steel Pipe Sizes

Spiral Submerged Arc Welded (SSAW) Pipes are available in a variety of sizes, typically measured by outside diameter (OD) and wall thickness. The most common size range is 16 inches to 100 inches (406mm - 2540mm) OD and 6mm to 25.4mm wall thickness. Custom sizes are also available to meet specific project requirements.

1. Small to Medium (16-36 inches)

● 16-20 inches: These sizes are commonly used in municipal water supply and drainage systems, as well as low-pressure oil and gas pipelines. Their relatively small size makes them easy to handle and install, ideal for small to medium-sized projects.

● 24-36 inches: This size range is commonly used for medium-pressure oil and gas pipelines, as well as structural applications such as building framing and bridges. They strike a good balance between strength and cost, suitable for a variety of projects.

2. Large Size (40-100 inches)

● 40-60 inches: These larger sizes are typically used for high-pressure oil and gas trunk lines and large-scale water supply and drainage projects. Larger inner diameters allow for higher flow velocities, making them ideal for transporting large volumes of fluid over long distances.

● 72-100 inches: This is the largest size achievable with SSAW steel pipes, commonly found in large-scale water diversion projects, urban ring roads, or offshore platform jacket structures. These extra-large diameter pipes are typically custom-made to meet the specific requirements of each project.

3. SSAW Steel Pipe & Tube Sizes Chart

The following is a table showing the common combinations of outer diameter and wall thickness for SSAW pipes (in mm).

Outer Diameter  (mm)	inch	Recommended Wall Thickness Range  (mm)	Common Steel Grades
219.1	8	6.0 - 10.0	Q235B, Q345B, L290(X42)
273.1	10	6.0 - 12.0	Q235B, Q345B, L290(X42)
323.9	12	6.0 - 14.0	Q235B, Q345B, L290(X42), L320(X46)
355.6	14	6.0 - 15.0	Q235B, Q345B, L290(X42), L320(X46)
406.4	16	6.0 - 16.0	Q235B, Q345B, L290-L360(X42-X52)
457.0	18	6.0 - 16.0	Q235B, Q345B, L290-L360(X42-X52)
508.0	20	6.0 - 20.0	Q235B, Q345B, L290-L415(X42-X60)
559.0	22	6.0 - 22.0	Q235B, Q345B, L290-L415(X42-X60)
610.0	24	6.0 - 25.4	Q235B, Q345B, L290-L415(X42-X60)
660.0	26	7.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
711.0	28	7.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
762.0	30	7.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
813.0	32	8.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
864.0	34	8.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
914.0	36	8.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
965.0	38	8.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
1016.0	40	9.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
1067.0	42	9.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
1118.0	44	9.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
1168.0	46	9.0 - 25.4	Q235B, Q345B, L290-L450(X42-X65)
1219.0	48	9.5 - 30.0	Q235B, Q345B, L290-L450(X42-X65)
1422.0	56	10.0 - 30.0	Q235B, Q345B, L290-L415(X42-X60)
1620.0	64	12.0 - 30.0	Q235B, Q345B (L360 and above can be customized)
1820.0	72	12.0 - 30.0	Q235B, Q345B (L360 and above can be customized)
2020.0	80	14.0 - 30.0	Q235B, Q345B (L360 and above can be customized)
2220.0	87	14.0 - 35.0	Q235B, Q345B (L360 and above can be customized)
2500.0	98	14.0 - 35.0	Q235B, Q345B (L360 and above can be customized)
2540.0	100	16.0 - 35.0	Q235B, Q345B (L360 and above can be customized)
3048.0	120	16.0 - 40.0	Q235B (L360 and above require special customization)

Steel Grade and Size Production Capacity Description:

a. Q235B/Q345B: All spiral pipe manufacturers can produce this; it is a standard material suitable for water supply, structural applications, and general fluid transportation.
b. X42–X52: Mainstream manufacturers can produce this according to API 5L standards; it is a common steel grade for export markets and oil and gas projects.
c. X56–X65: Capable manufacturers can produce this; it usually requires GB/T 9711 or API 5L PSL2 certification.
d. X70: Only a few leading companies can produce this; it requires API 5L PSL2 qualification and is used in national trunk pipeline networks.
e. X80 and above: Very few large companies can produce this; SSAW faces technical bottlenecks in the high-grade steel field, and large-diameter high-pressure pipelines increasingly use straight seam submerged arc welded pipes (LSAW).

It also needs to meet specific technical requirements: 

It typically needs to meet API 5L PSL2 standards; 

It may require special coatings such as 3PE anti-corrosion coating; 

It needs to confirm production capacity and delivery time with the manufacturer in advance.

Factors influencing SSAW Pipe Size Selection:

1. Flow Rate
The required flow rate will determine the minimum diameter of the SSAW steel pipe. Larger diameter pipes can achieve higher flow rates, but may also be more expensive and require more installation space.

2. Pressure
The operating pressure of the SSAW steel pipe determines the required wall thickness. Higher pressures require thicker walls to ensure the pipe can withstand the pressure without bursting.

3. Application
The specific application of the SSAW steel pipe will also affect the size selection. For example, pipes used for structural applications may require different sizes and wall thicknesses than those used for fluid transport. The selection logic for structural pipes differs from that for fluid transport pipes; the former prioritizes stiffness and section modulus, while the latter prioritizes pressure resistance.

4. Cost
The cost of SSAW steel pipes is a significant consideration, especially in large-scale projects. From an engineering economics perspective, while increasing the pipe diameter raises material costs, it significantly reduces energy consumption for the transported medium, requiring a comprehensive comparison.

Applications of SSAW Steel Pipes:

SSAW steel pipes are widely used in numerous industries and fields, including:

1. Oil and Gas

Due to its high strength, good low-temperature toughness, and weldability, combined with excellent corrosion resistance after applying external anti-corrosion coatings such as 3PE, SSAW steel pipes are one of the main choices for long-distance oil and gas pipelines. It can withstand the high pressure and harsh environmental conditions common in the oil and gas industry.

2. Water Supply and Drainage Systems

Widely used in urban water supply trunk lines and large-scale water diversion projects. The smooth inner surface ensures low hydraulic friction, while the spiral structure provides good rigidity and resistance to external pressure.

SSAW steel pipes are widely used in above-ground and underground water supply and drainage systems. Its smooth inner surface effectively reduces water flow friction resistance, while the robust pipe structure resists external loads, soil corrosion, and mechanical damage, ensuring long-term operational safety.

3. Structural Support
SSAW steel pipes are also widely used in building frames, bridge pile foundations, and offshore platform jackets. Their high strength-to-weight ratio makes them an ideal load-bearing structural material.

4. Other Industries
SSAW steel pipes are also used in mining (slurry transportation), power generation (circulating water pipelines), and manufacturing. Their versatility and durability make them an ideal choice for many industrial applications.

Application Size Selection Recommendation Table:

Application Scenarios	Recommended Outer Diameter (mm)	Recommended Wall Thickness (mm)	Recommended Steel Grade	Remarks
Urban Water Supply Branch Line	219 - 406	6 - 8	Q235B / L245	Low Pressure, Small Flow
Urban Water Supply Main Pipeline	508 - 1020	8 - 14	L290	Medium Pressure, Medium Flow
Large-scale Water Diversion Project	1220 - 2500	10 - 20	Q355B / L360	Large Flow, Long Distance
Oil and Gas Gathering Pipeline	219 - 610	6 - 12	X42 - X60	Medium and Low Pressure
Long-distance Oil and Gas Main Pipeline	610 - 1219	10 - 25	X65 - X80	High Pressure, Large Flow
Building Structure Pile Foundation	406 - 914	8 - 16	Q355B / ASTM A252	High Load-bearing Requirements
Bridge Engineering	610 - 1220	10 - 20	Q355B / X65	High stiffness requirement
Offshore Wind Power Foundation	1220 - 3048	16 - 40	X70 / X80	Extreme environment
Tunnel casing	1422 - 3500	14 - 30	Q235B / L245	Non-pressure application

Comparison with Other Types of Steel Pipes:

While SSAW steel pipes have significant advantages in large-diameter applications, electric resistance welded pipes (ERW) are a common alternative in small-diameter applications.

● ERW Steel Pipes: These are formed by extruding steel strips after heating the edges with an electric current. Their advantages include extremely high dimensional accuracy and low manufacturing costs, making them ideal for oil and gas gathering and transportation, and mechanical structural components with an outer diameter less than 24 inches.

● SSAW Steel Pipes: Their advantage lies in the dimensional flexibility provided by their continuous spiral weld seam, enabling the production of large-diameter steel pipes far exceeding the width of the strip, suitable for fluid transportation requiring large diameters and medium wall thicknesses.

Selection Recommendations: Generally, a 24-inch (610mm) outer diameter is the dividing line. For sizes smaller than this, ERW steel pipes, which offer better cost-effectiveness and precision, are preferred. For sizes larger than this, or when extremely thick walls are required, spiral welded pipes are the mainstream choice.

Limitations:

Although SSAW steel pipes are widely used, careful selection or consideration of alternative pipe types is necessary in the following scenarios:

● High-pressure natural gas trunk lines (X80 and above steel grades): Straight seam submerged arc welded pipes (LSAW) are generally more advantageous due to their shorter weld seams and higher dimensional accuracy.
● Small-diameter pipelines (outer diameter less than 16 inches): Resistance welded steel pipes (ERW) or seamless steel pipes offer lower cost and higher precision.
● Highly corrosive media: Internal anti-corrosion coatings (such as FBE, cement mortar lining) or stainless steel/duplex steel pipes are required.

Read more: SSAW Steel Pipe Manufacturing Process or ERW Pipe Wall Thickness Size Chart