ASTM A358 CL1 TP321/TP321H Welded Pipe 355.6×6.35×5970MM – Pickled Surface, 100% RT

Introduction

The ASTM A358 CL1 TP321/TP321H Welded Pipe is an austenitic stainless steel pipe designed for high-temperature service in boilers, heat exchangers, and refinery piping systems. The stabilizing element titanium in TP321 prevents carbide precipitation during welding, while TP321H (high-carbon version) offers enhanced creep and high-temperature strength.

DLSS supplied 355.6 mm OD × 6.35 mm WT × 5970 mm length welded pipes, manufactured to ASTM A358 Class 1, with pickled surface finish and 100% Radiographic Testing (RT) for quality assurance.

Key Features

• Material: Stainless Steel TP321 / TP321H

• Standard: ASTM A358 Class 1

• Type: Welded Pipe

• Size: 355.6 mm OD × 6.35 mm WT × 5970 mm Length

• Surface Finish: Pickled (oxide-free, corrosion-protected)

• Testing: 100% Radiographic Testing (RT) for weld integrity

• Temperature Resistance: Suitable for service up to 870°C

• Strength: Excellent creep and stress rupture strength

Specifications

Advantages of TP321/TP321H

• Titanium Stabilization – resists intergranular corrosion after welding.

• High-Temperature Strength – TP321H grade provides improved creep resistance.

• Oxidation Resistance – performs well in continuous service up to 870°C.

• Weldability – excellent fabrication properties for complex piping systems.

• Surface Protection – pickling improves corrosion resistance and cleanliness.

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Applications

• Power Generation – boiler piping, superheater tubes.

• Petrochemical Industry – high-temperature refinery piping systems.

• Heat Exchangers – handling hot gases and fluids.

• Chemical Plants – piping for aggressive chemicals at elevated temperatures.

• Industrial Furnaces – components exposed to high-heat cycles.

Quality Assurance

DLSS ensures every pipe meets international standards with:

• 100% Radiographic Testing (RT) – detects weld defects.

• PMI Testing – confirms chemical composition.

• Hydrostatic Testing – ensures pressure integrity.

• Dimensional & Surface Inspection – guarantees compliance.

• Third-Party Inspection – SGS, BV, TUV available on request.

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FAQ

Q1: Why choose TP321/TP321H over TP304/TP316?
A1: TP321/321H contains titanium, which improves resistance to intergranular corrosion and provides better creep strength at high temperatures.

Q2: What is ASTM A358 CL1?
A2: ASTM A358 Class 1 specifies double-welded pipes fully radiographed to ensure maximum weld integrity.

Q3: Why use 100% RT?
A3: 100% Radiographic Testing verifies that weld seams are defect-free, ensuring reliability in critical high-temperature systems.

Why Choose DLSS?

• Specialized in stainless steel welded pipes for boilers and heat exchangers.

• Over 30 years of experience supplying to global EPCs and end-users.

• Strict QC and NDT compliance with ASTM/ASME standards.

• Seaworthy packaging with capped ends, PE wrap, and wooden cases.