Large-Diameter, Thick-Walled TP304L Welded Pipe
Outer Diameter (OD)：14" to 100" (355.6 mm – 2540 mm)
Wall Thickness (WT)：6.0 mm – 80 mm (Up to SCH 160 or custom)
Welding Method：EFW (Electric Fusion Welding), LSAW (Longitudinal Submerged Arc Welding)
Standard Length：6m, 12m, or Double Random Lengths (DRL)
Standards：ASTM A358 (Class 1, 2, 3, 4, 5), ASTM A312, ASTM A813, ASTM A814
End Finish：Plain End, Beveled End, or Threaded
Transport Package：Standard Sea-Worthy Packing
Large-Diameter, Thick-Walled TP304L Welded Pipe Manufacturers and Suppliers
GNEE is a reliable supplier for large-scale projects such as pressure vessels, seawater cooling systems, flue gas desulfurization (FGD) units, and food-grade storage tanks. With stable performance, we help customers reduce installation difficulty and long-term maintenance costs for large engineering projects.
We provide large-diameter, thick-walled TP304L welded pipes manufactured to ASTM A312/A358 standards, specifically designed for main process pipelines, structural supports, and low-pressure conveying systems in large chemical, power, and marine engineering projects.
Our TP304L stainless steel welded pipes are produced using automatic gas tungsten arc welding (GTAW) or multi-wire submerged arc welding (SAW) processes. After welding, the pipes undergo an online solution heat treatment at temperatures ranging from 1065-1120°C, ensuring that the welds and base material exhibit the same corrosion resistance and mechanical properties, completely eliminating residual welding stresses.
To address the deformation challenges of large-diameter TP304L pipes, we apply specialized straightening and sizing processes, controlling the ovality to ≤0.5% OD and straightness to ≤1.5mm/m, ensuring smooth on-site installation.
We focus on large sizes, with an outer diameter range from 114 mm to 1220 mm and wall thickness from 3.0 mm to 40 mm. We can also customize pipe lengths to meet client requirements, with lengths up to 12 meters. Size tolerances are controlled within ±0.1 mm for outer diameter and ±0.08 mm for wall thickness. Our advanced longitudinal welding process, combined with full-pipe ultrasonic testing, radiographic testing (RT), and water pressure testing up to 60 MPa, ensures defect-free welds and excellent sealing performance under high pressure.
Every pipe undergoes 100% real-time X-ray imaging (RT) and ultrasonic testing (UT), with ferrite content measurement (typically ≤5 FN) of the welds and heat-affected zones, ensuring stable microstructure and eliminating the risk of failure under high temperatures or corrosive conditions.
All pipes come with material certificates that comply with EN 10204 3.2, and we can provide complete reports covering PMI, intergranular corrosion testing (ASTM A262 Practice E), and water pressure testing.
Click to obtain the Material Test Certificate
Specification
| Product Name | 304L Welded Stainless Steel Pipes /Tubes | |
| Standard | ASTM A312/A358 | |
| Welding Line Type | EFW / ERW / PAW /GTAW | |
| Specification | Outer diameter | 168mm-1828mm DN150-1800 6nch -72 inch |
| Wall thickness | 3mm-60mm SCH5s, SCH10S ,SCH10 ,SCH20, SCH30, SCH40s, SCH STD, SCH40, SCH60, SCH80s, SCH XS, SCH100, SCH120, SCH140, SCH160, SCHXXS |
|
| Length | 6M,12M or as customer's actual request | |
| Surface | Annealing&Pickling, Polishing (180#-600#), Bright Annealing, Sand Blasting,Shot Blasting | |
| Hydraulic pressure testing | OD≤1.5m | |
| RT(X-Ray) Inspection | 100% filming Class 1 / 2 / 3/ 4/ 5 | |
| Delivery Time | 1.for ready stock :7 days after receiving the deposit of T/T 2.For MTO: 35 days after receiving the deposit of T/T |
|
| Trade Terms | EXW,FOB, CFR, CIF etc. | |
Click to Customize 304/304L Stainless Steel Tubes
TP304L UNS S30403 pipe Chemical Composition
The "L" grade ensures that the carbon content remains low to prevent carbide precipitation during the welding of thick sections.
| Element | Carbon (C) | Manganese (Mn) | Silicon (Si) | Chromium (Cr) | Nickel (Ni) | P / S (Max) | Nitrogen (N) |
| Value (%) | ≤ 0.030 | ≤ 2.00 | ≤ 0.75 | 18.0 - 20.0 | 8.0 - 12.0 | 0.045 / 0.030 | ≤ 0.10 |
Mechanical Properties
Thick-walled welded pipes must maintain high structural integrity at the weld seam.
| Property | Value (Minimum) |
| Tensile Strength (Rm) | ≥ 485 MPa (70 ksi) |
| Yield Strength (Rp0.2) | ≥ 170 MPa (25 ksi) |
| Elongation (A5) | ≥ 35% |
| Hardness (Brinell) | ≤ 192 HBW |
ASTM A358 Class Classifications (For Large Diameter)
For thick-walled welded pipes, the class determines the level of inspection and welding quality.
Class 1: Double welded, 100% Radiographic Testing (RT) for all welds.
Class 2: Double welded, no radiography.
Class 3: Single welded, 100% RT.
Class 4: Single welded, but the weld pass exposed to the inside pipe surface may be made without addition of filler metal.
Class 5: Double welded, spot radiography.
What is the difference between ASTM A312 and ASTM A358 for welded pipes?
A312 is typically used for standard sizes and general corrosive service. A358 is the preferred standard for large-diameter (NPS 8" to 100") and thick-walled pipes intended for high-temperature and heavy industrial service.
inspection
We provide Manufacturer TC (Test Certificate) in accordance to EN 10204/3.1B, Raw Materials Certificate, 100% Radiography Test Report, Third Party Inspection Report. We also provide Standard certificates like EN 10204 3.1 and additional requirement like. NACE MR 01075.
• EN 10204/3.1B
• Raw Materials Certificate
• 100% Radiography Test Report
• Third Party Inspection Report
TP304L Welded Pipe Manufacturers
1. With over 18 years of manufacturing experience, we are dedicated to serving you.
2. Fastest delivery speeds.
3. Lowest prices.
4. We offer the most comprehensive range of standards and materials for you to choose from.
5. 100% of our products are for export.
6. Our products are exported to regions including Africa, Oceania, the Middle East, East Asia, and Western Europe.
high quality packaging
All of our stainless steel seamless pipe & tubes are packaged as per international standard to prevent any possible damage or loss. By default, we will use thick woven plastic bag to bundle the finished pipes together in batches.
Hot Tags: large-diameter, thick-walled tp304l welded pipe, China large-diameter, thick-walled tp304l welded pipe manufacturers, suppliers, factory, ASTM A554 Stainless Steel Tubing, Square Shape Weldable 904L 409L Steel Tube, stainless steel welded pipe assembly, stainless steel welded pipe specifications, stainless steel welded tubing assembly, welded stainless steel tubing dimensions
You Might Also Like
Send Inquiry