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Stainless Steel Welded Pipe ASTM A312 (Grades 304, 316L) | Factory Price

SKU: TDC-PIPE-WELDED
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Industrial Welded Stainless Steel Pipe (ASTM A312 / ASME SA312)

  • Available Alloys: Grades 304/304L (General Fluid Lines) and 316L (High-Corrosive Chemical Systems)
  • Wall Thickness (Schedule): Sch 5S (Lightweight), Sch 10S (Standard), and Sch 40S (Heavy-Duty)
  • Dimensions: NPS 1/4" up to 24" in stock (Standard 6-meter length)
  • Services & Logistics: Dual Certified, MTC included, custom bandsaw cutting, and nationwide shipping

Uniform wall thickness and highly cost-effective compared to seamless alternatives. Ideal for liquid, air, and chemical piping systems.

ISO Certification
High Performance
Industrial Material

Why Welded Stainless Steel Pipes (ASTM A312) Are the Smartest Choice for Process Piping?

For water, air, or moderate-pressure chemical process piping systems in industrial plants, the main challenge for engineers and procurement managers is controlling material budgets without sacrificing safety or longevity. ASTM A312 Welded Stainless Steel Pipes are the ultimate solution to this engineering challenge.

Unlike seamless pipes, welded pipes are roll-formed from premium flat sheet metal and welded along a longitudinal seam using advanced welding technologies (such as ERW or EFW). This manufacturing process guarantees an **extremely tight, uniform wall thickness (concentricity)** throughout the entire length of the pipe—a distinct advantage over seamless alternatives. Crucially, they are significantly more cost-effective, allowing you to lower project procurement costs substantially.


Weight and Dimensions Chart: Stainless Steel Welded Pipes

Spec : ASTM A312 / A358 / A778 , ASME B36.19M (Our inventory is Dual Certified to satisfy both structural and pressure-specific mechanical codes effortlessly)

NPS (Inch) OD (mm) Nominal Wall Thickness
Schedule 5S (Light Wall) Schedule 10S (Standard Wall) Schedule 40S (Heavy Wall)
Thk (mm) kg/m Thk (mm) kg/m Thk (mm) kg/m
1/413.72--1.650.502.240.64
3/817.15--1.650.652.310.85
1/221.341.650.812.111.012.771.28
3/426.671.651.032.111.292.871.70
133.401.651.302.772.113.382.53
1 1/442.161.651.672.772.723.563.42
1 1/248.261.651.922.773.143.684.09
260.331.652.412.773.973.915.50
2 1/273.032.113.733.055.325.168.72
388.902.114.563.056.525.4911.40
3 1/2101.602.115.233.057.495.7413.70
4114.302.115.903.058.456.0216.20
5141.302.779.563.4011.706.5522.00
6168.282.7711.403.4014.007.1128.50
8219.082.7714.903.7620.208.1843.00
10273.053.4022.804.1928.109.2760.90
12323.853.9631.604.5736.309.5374.60
14355.603.9634.704.7841.809.5382.20
16406.404.1942.004.7847.809.5394.20
18457.204.1947.304.7853.909.53106.30
20508.004.7859.905.5469.309.53118.30
22558.804.7866.005.5476.40--
24609.605.5483.406.3595.409.53142.50
30762.006.35119.507.92148.80--
32 - 80 Extra thick-wall sizes (6.35 to 30.00 mm) available. Please consult our sales team for custom fabrications.

Tolerance Table

We maintain highly strict dimensional tolerance criteria for our welded pipes to ensure smooth on-site alignment and precise valve integration.

Standard Outside Diameter (OD) Wall Thickness Length
CNS 6331 < 30mm: ± 0.3mm / ≥ 30mm: ± 1% < 2mm: ± 0.2mm / ≥ 2mm: ± 10% As requested
JIS G3459 ± 1% (Min ± 0.3mm) ± 10% (Min ± 0.2mm) As requested
ASTM A312 ≤ 48.26: +0.4 / -0.8 mm
> 48.26 - 114.3: ± 0.8 mm
Nominal Thickness ± 12.5% + 6.0 mm / - 0 mm
ASTM A358 ± 0.5% - 0.30 mm L ≤ 7.3m: + 6 mm

Frequently Asked Questions (FAQ)

We stock an extensive range starting from small NPS 1/4" (OD 13.72 mm) up to large NPS 24" (OD 609.6 mm), with custom sizes up to 80" available on request. Standard stocks are available in Schedule 5S (light wall), Schedule 10S (standard wall), and Schedule 40S (heavy wall) across Grades 304, 304L, and 316L.
- Schedule 5S is the thinnest, lightest, and most economical, ideal for low-pressure drainage and exhaust ducts.
- Schedule 10S is the standard industrial wall thickness used widely across chemical and fluid transport lines.
- Schedule 40S is the thickest option, engineered for high-pressure durability; highly recommended for steam lines, high-pressure pumps, and aggressive chemical piping.
Dual Certification means the pipes comply simultaneously with ASTM A312 (general mechanical standards) and ASME SA312 (boiler and pressure vessel safety codes). This provides mechanical contractors with immense convenience, allowing one single material spec to satisfy strict compliance audits under both regulatory codes.
Welded pipes are cold-formed from flat metal sheets and welded longitudinally, resulting in highly uniform wall thickness and lower costs, ideal for general industrial processing. Seamless pipes are pierced from solid billets, meaning they have no weld seams at all. While seamless pipes can tolerate extreme high-pressures, they often exhibit slight wall-thickness variations and are far more expensive.
Yes, we do. While standard pipes are delivered in 6-meter lengths, we operate in-house bandsaw cutting services. You can provide us with your exact length specifications to eliminate on-site cutting labor and reduce expensive material scrap at your facility.
Yes, 100%. Every delivery of our stainless steel welded pipes is accompanied by a Mill Test Certificate (MTC) and a Material Test Report (MTR) confirming chemical and tensile specifications in compliance with ASTM A312. Supported by our professional logistics fleet, we offer fast and secure nationwide delivery across Thailand.
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