ASTM A358 Class 2 TP304 Stainless Steel Pipe

With over 18 years of professional expertise in stainless steel pipe manufacturing, GNEE has successfully delivered more than 200 projects across the energy and petrochemical sectors. Our TP304 EFW pipes are manufactured in strict accordance with ASTM A358 / ASME SA358 standards, specifically engineered for general corrosive and medium-temperature service environments.

 

GNEE Stainless Steel supplies ASTM A358 Class 2 TP304 stainless steel pipes utilizing a double-welded process with the addition of filler metal in all passes. Each pipe undergoes a full solution annealing treatment at temperatures above 1050°C, followed by 100% full-length radiographic testing (RT) to ensure a weld defect detection rate approaching 100%. These pipes are designed to maintain stable performance across a wide temperature range from -196°C to 425°C, offering over a 40% increase in high-temperature service life compared to standard welded pipes. They are the ideal solution for large-diameter, medium-to-low pressure corrosive transport applications.

 

 

Our ASTM A358 Class 2 TP304 piping range covers outside diameters from 1/2" to 110" (21.3–2794 mm), with wall thicknesses spanning SCH 5S to SCH 160. We adhere to precise manufacturing tolerances of ±1% for OD and ±10% for wall thickness. While standard random lengths are 5.8–6.1 meters, we also provide custom lengths up to 12.5 meters. All pipes are Solution Annealed & Pickled (A&P) and supplied with EN 10204 3.1 Material Test Certificates (MTC). GNEE further offers value-added services such as beveling, precision cutting, and surface finishing, with extensive stock available for rapid delivery and dedicated technical support for project-specific requirements.

 

ASTM A358 Class 2 TP304 EFW Pipe

Parameter Category	Technical Details & Specifications
Standard Specification	ASTM A358 / ASME SA358 (Electric-Fusion-Welded Austenitic Pipe)
Material Grade	TP304 (UNS S30400)
Weld Class (Class 2)	Double Welded: Filler metal added in all passes; involves inner and outer weld beads.
Size Range (OD)	1/2" to 110" (21.3 mm – 2794 mm)
Wall Thickness (WT)	SCH 5S to SCH 160 (Custom wall thicknesses available upon request)
Pipe Length	Single Random (5.8m–6.1m), Double Random, or Custom lengths up to 12.5m
Heat Treatment	Full Solution Annealing: Temperature ≥1050°C (1920°F) followed by rapid water quenching.
Surface Condition	Annealed & Pickled (A&P); Passivated; or Sand Blasted.
Mandatory Testing	Hydrostatic Test, Transverse Guided-Weld Bend Test, Tension Test.
Quality Control (RT)	100% Full-length Radiographic Testing (RT) (Standard for GNEE Quality Assurance).
Certification	EN 10204 3.1 Mill Test Certificate (MTC), NACE MR0175 (Optional).
End Connections	Plain End (PE), Beveled End (BE) for welding, or Threaded (NPT).

 

Chemical Composition of ASTM A358 TP304

Grade	UNS Designation	C (Carbon)	Mn (Manganese)	Si (Silicon)	P (Phosphorus)	S (Sulfur)	Cr (Chromium)	Ni (Nickel)	N (Nitrogen)
TP304	S30400	≤ 0.08	≤ 2.00	≤ 1.00	≤ 0.045	≤ 0.030	18.0 – 20.0	8.0 – 11.0	≤ 0.10

 

Mechanical Properties of ASTM A358 TP304

Grade	Tensile Strength (min)	Yield Strength (min)	Elongation in 2 in. (min)	Hardness (Max)
TP304	515 MPa (75 ksi)	205 MPa (30 ksi)	35%	192 HBW / 90 HRB

 

ASTM A358 Stainless Steel Welded Tubes Tolerances

Standard	Outside Diameter Tolerance(mm)		Thickness Tolerance		Length Tolerance (mm)
ASTM A358	Based on circumferential measurement ±0.5%; Difference between major and minor outside diameters 1%		-0.3mm		L≤7.3M +6/-0 mm

 

What is the difference between ASTM A358 Class 1 and Class 2?

Both classes require double-sided welding using filler metal. The primary difference lies in the radiographic testing (RT) requirements:
Class 1: 100% radiographic testing of the entire length of all welds is mandatory.
Class 2: Radiographic testing is not mandatory under the standard, but it may be performed as a supplementary requirement to increase the joint efficiency factor (E).

 

ASTM A358 Class 2 TP304 Pipe Applications

Chemical and petrochemical processing;
Water and wastewater treatment systems;
Mechanical and general structural applications;
High-temperature piping and cryogenic service conditions.

 

if you have project requirements for ASTM A358 TP304 stainless steel pipes, you are welcome to place an order. GNEE maintains a large inventory of popular products for you to choose from.

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 Delivery & Lead Time

Order Type	Standard Lead Time	Notes
In-Stock Items	7 – 10 Days	Available for standard sizes (NPS 8" to 24") in common schedules.
Custom Production	25 – 45 Days	Includes plate sourcing, EFW welding, heat treatment, and 100% RT.
Large-Scale Projects	Scheduled Shipments	Staggered delivery according to project phases (Batch shipments).

Shipping Port: Tianjin, Qingdao, or Shanghai, China.

Trade Terms: FOB, CFR, CIF, DDP

 

Quality Inspection

Although the Class 2 standard does not mandate full-length radiographic testing (RT), every pipe undergoes 100% hydrostatic testing and visual weld inspection in strict accordance with standard requirements; additionally, supplementary inspection services-such as RT, ultrasonic testing (UT), or eddy current testing (ET)-can be provided upon the buyer's request.

Sea-Worthy Packaging & Handling

End Protection: Plastic or metal pipe caps are fitted to protect the Beveled Ends (BE) or Plain Ends (PE) from deformation.
Surface Protection: Each pipe is wrapped in polyethylene (PE) sleeves or waterproof plastic sheets to prevent atmospheric corrosion.
Bundling & Support:
Large-bore pipes are supported by internal cross-bracing or wooden/steel cradles to maintain circularity (ovality control).
Secure Crating: High-value or thin-walled pipes are packed in fumigation-free wooden cases or reinforced steel frames.
Professional Stenciling: Each pipe is clearly marked with:
Manufacturer (GNEE), Specification (ASTM A358), Grade (TP304), Class (2), Size (OD x WT x Length), and Heat Number.