321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes

High-Carbon Titanium-Stabilized Grade • Superior Creep Strength • Extreme Heat Performance

Manufacturers and suppliers of 321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes, engineered for sustained high-temperature, high-pressure, and corrosive service environments in petrochemical plants, refineries, aerospace systems, and power generation facilities.

ISO 9001:2015 • ISO 14001:2015 • ISO 45001:2018 • PED 2014/68/EU • EN 10204 3.1/3.2 Certified

321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes

Our 321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes are specially engineered for high-temperature and high-pressure applications where enhanced mechanical strength and superior oxidation resistance are critical. Manufactured from 321H stainless steel, a high-carbon, titanium-stabilized grade, these tubes offer excellent resistance to intergranular corrosion, even after prolonged exposure to elevated temperatures and welding conditions.

Designed to perform reliably at temperatures of up to 900°C (1,650°F), these seamless tubes are widely used in chemical processing plants, power generation facilities, petrochemical systems, and thermal processing industries. The precision seamless construction ensures smooth internal surfaces, reducing turbulence, minimizing pressure loss, and promoting efficient fluid flow in critical hydraulic and instrumentation systems.

With outstanding resistance to pitting, crevice corrosion, and aggressive chemical environments, 321H stainless steel tubes provide long-term durability, reduced maintenance requirements, and consistent performance in demanding service conditions. Available in a wide range of sizes and specifications, they deliver a reliable, high-performance solution for critical industrial applications requiring strength, heat resistance, and corrosion protection.

321H Stainless Steel Seamless Hydraulic and Instrumentation Tubes

Comprehensive Global Reach

Our 321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes are trusted across major industrial cities in India, including Mumbai, Chennai, Pune, and Ahmedabad, supporting petrochemical plants, refineries, power generation facilities, and high-temperature industrial projects that demand reliable, oxidation-resistant, and corrosion-resistant tubing solutions.

Throughout the Middle East, we supply the UAE (Dubai, Abu Dhabi, Sharjah, Ajman, Ras Al Khaimah, and Al Ain), Saudi Arabia, Qatar, Kuwait, Oman, Bahrain, Iraq, Jordan, Yemen, Lebanon, Syria, Azerbaijan, and Georgia. Our 321H stainless steel seamless tubes are widely used in oil & gas processing, water treatment facilities, power generation, and EPC projects operating under extreme heat, pressure, and aggressive service conditions.

Europe, Africa, Americas & Asia-Pacific

In Europe, our tubes serve Italy, Spain, Germany, France, the United Kingdom, Greece, Austria, Turkey, Russia, Ukraine, and Eastern European and Central Asian markets. Across Africa, the Americas, and the Asia-Pacific region—including the United States, Canada, Brazil, Mexico, Argentina, South Africa, Nigeria, Egypt, Morocco, Kenya, Singapore, Malaysia, Thailand, Vietnam, Sri Lanka, and Australia— our 321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes support chemical processing plants, offshore platforms, power stations, heavy manufacturing, and thermal processing industries.

Commitment to Quality

Wherever you operate—Doha, Dubai, London, Moscow, New York, Singapore, or Sydney— Seminox Pipes & Tubes delivers premium-quality 321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes, manufactured and certified to international standards to ensure precision, full traceability, and long-term performance in critical fluid control and high-temperature instrumentation applications worldwide.

Key Features of 321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes

Precision Seamless Manufacturing

Manufactured using advanced cold drawing and seamless forming processes to achieve uniform wall thickness, tight dimensional tolerances, and smooth internal surfaces for consistent fluid flow and precise instrumentation performance.

High-Carbon Titanium-Stabilized Grade

The high-carbon, titanium-stabilized composition of 321H improves high-temperature strength and creep resistance while preventing carbide precipitation, ensuring excellent resistance to intergranular corrosion after welding and prolonged heat exposure.

Exceptional Oxidation & Heat Resistance

Provides reliable performance in continuous service at elevated temperatures, resisting oxidation, scaling, and thermal fatigue in heat-intensive industrial and process environments.

Smooth Bore for Accurate Flow Control

Precision-finished internal surfaces reduce friction, minimize pressure loss, and enhance flow stability for sensitive hydraulic and instrumentation systems.

High Strength & Thermal Stability

Maintains mechanical integrity and dimensional stability under high pressure, severe thermal cycling, and continuous elevated-temperature operating conditions.

Long Service Life & Reduced Maintenance

Engineered for extended durability, reduced downtime, and lower lifecycle costs in petrochemical plants, refineries, power generation facilities, aerospace systems, and high-temperature process industries.

Product Specification – 321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes

Outside Diameter
6.00 mm to 114.30 mm (1/4” to 4.5”)
Wall Thickness
0.71 mm to 12.70 mm (0.028” to 0.500”)
Grade / Material
Austenitic Stainless Steel (Titanium Stabilized, High Carbon)
AISI 321H
UNS S32109
EN 1.4878
Manufacturing Process
Seamless (Cold Drawn / Cold Rolled) • Solution Annealed • Pickled / Bright Annealed
Standards & Specifications
ASTM A213 / A213M – Seamless Stainless Steel Tubes (Instrumentation & Heat Transfer)
ASTM A269 – General Service Stainless Steel Tubing
ASTM A511 – Mechanical Tubing
ASME SA213 / SA269
EN 10216-5 (Seamless Precision Tubes)
Customer Drawings & EPC / Project Specifications
Length
Standard: 6 meters • Random Lengths • Up to 18 meters
Custom cut lengths as per Project / Instrumentation Requirements
Surface Finish
Annealed & Pickled (AP), Bright Annealed (BA),
Polished (180 / 240 / 320 / 400 / 600 Grit), Electropolished
Mechanical Properties (Typical)
Yield Strength: ≥ 205 MPa
Tensile Strength: 515–690 MPa
Elongation: ≥ 40%
Enhanced Creep Strength at Elevated Temperatures
Applications
High-Temperature Hydraulic & Instrumentation Lines,
Petrochemical & Refinery Systems,
Power Generation & Thermal Processing Plants,
Aerospace & Heat-Resistant Equipment,
Chemical Processing Units,
High-Pressure & High-Heat Fluid Transfer Systems,
Oxidizing & Elevated-Temperature Service Environments

Manufacturing, Testing & Quality Assurance – 321H Stainless Steel Tubes

Advanced Manufacturing

321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes are manufactured using precision cold drawing and cold rolling processes, followed by controlled solution annealing and pickling or bright annealing. The titanium-stabilized, high-carbon composition ensures a fully austenitic, homogeneous microstructure with enhanced high-temperature strength, excellent oxidation resistance, and superior resistance to intergranular corrosion—delivering tight dimensional tolerances and consistent performance in high-pressure and elevated-temperature hydraulic and instrumentation service environments.

Inspection & Testing

Each tube undergoes comprehensive quality control including Eddy Current Testing (ECT), Hydrostatic or Pneumatic Pressure Testing, Positive Material Identification (PMI), chemical composition verification, mechanical and elevated-temperature performance testing, dimensional inspection, and 100% visual examination. These procedures ensure full compliance with ASTM A213 / A269 and ASME SA213 / SA269 standards for safe, reliable operation in critical, corrosive, and high-temperature service conditions.

Certifications & Compliance

Manufactured in accordance with ASTM A213, ASTM A269, ASME SA213, ASME SA269, EN 10216-5, ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, and PED 2014/68/EU directives. Tubes are supplied with EN 10204 3.1 / 3.2 Mill Test Certificates (MTC), ensuring full traceability, regulatory compliance, and acceptance for EPC, petrochemical, power generation, refinery, chemical processing, aerospace, and offshore projects worldwide.

Typical Applications of 321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes

High-Temperature Hydraulic & Pneumatic Control Systems
Precision Instrumentation & Process Control Lines
Petrochemical & Refinery Piping Systems
Chemical Processing & Corrosive Fluid Handling Units
Power Generation & High-Heat Energy Systems
Industrial Heating & Furnace Equipment
High-Pressure & High-Temperature Fluid Transfer Lines
Heat Exchangers & Thermal Management Systems
Aggressive Chemical, Chloride-Rich & Critical Service Environments

Need 321H Stainless Steel Seamless Hydraulic & Instrumentation Tubes for Your Project?

Partner with Seminox Pipes & Tubes for certified, project-ready 317H Stainless Steel Seamless Hydraulic & Instrumentation Tubes manufactured to international standards and supplied with EN 10204 3.1 / 3.2 Mill Test Certificates (MTC). Trusted globally for petrochemical, chemical processing, power generation, and high-temperature industrial applications requiring superior corrosion resistance, enhanced creep strength, and long-term reliability in critical and heat-intensive service environments.

Get in Touch

Phone Number

022 6659 5296
+91 9987403801
+918433943801

Email

domestic@seminoxpipes.com
export@seminoxpipes.com

Address

1219 / 1220, 12th Floor, Prasad Chambers, Girgaon, Mumbai- 400004

Business Hours

Monday — Friday 9am – 5pm
Saturday — 10am – 3pm
Sunday — Closed

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