DLSS Heat Exchanger Tubes Duplex Heat Exchanger Tubes

Duplex Heat Exchanger Tubes

High-strength duplex stainless steel tubes for heat exchangers, condensers and process equipment operating in chloride-containing and demanding industrial environments.

Available in UNS S31803 and S32205, with straight, U-bend and customized long-length configurations according to project requirements.

Duplex Material Range

S31803 · S32205

Wall Requirements

Average WT · Minimum WT

U-Bend Available

Custom straight-leg length & bend radius

Inspection Support

PMI · ET · UT · Hydro · 3.1 / 3.2

Duplex Tubes for Demanding Heat Exchanger Service

Duplex stainless steel heat exchanger tubes combine high mechanical strength with strong resistance to demanding corrosion environments, making them suitable for heat exchangers handling chloride-containing process fluids and other aggressive service conditions.

S31803 and S32205 are commonly specified within the duplex 2205 family for applications where conventional austenitic stainless steels may not provide the required combination of strength and corrosion performance.

Material selection should consider:

Process fluid
Chloride concentration
Operating temperature
Design pressure
Corrosion mechanism
Required mechanical strength
Applicable tube standard
Heat-treatment requirements
Inspection requirements

DLSS supports duplex tube projects from specification review and material confirmation through tube supply, U-bending, heat treatment, inspection, documentation and delivery.

ASTM A789 covers seamless and welded ferritic/austenitic stainless steel tubing, which is why it belongs at the center of this product page rather than ASTM A790 pipe.

High Strength

Suitable for demanding pressure and structural requirements.

Chloride Resistance

Duplex material options for chloride-containing service.

Custom Tube Forms

Straight, U-bend and long-length configurations.

Inspection Control

PMI, NDE and project documentation support.

Duplex Grades We Supply

Select the grade according to process conditions, corrosion requirements and project specification.

UNS S31803

S31803 Duplex Stainless Steel

Duplex stainless steel grade for heat exchanger applications requiring increased strength and improved corrosion performance compared with conventional austenitic stainless steels.

Typical Applications

Chemical Processing · Process Heat Exchangers · Oil & Gas · Industrial Cooling

UNS S32205

S32205 Duplex Stainless Steel

Widely specified duplex stainless steel for demanding heat exchanger service requiring a combination of mechanical strength and corrosion resistance.

Typical Applications

Chemical Processing · Chloride-Containing Service · Oil & Gas · Heat Exchangers

Available Duplex Tube Forms

Different heat exchanger designs require different tube configurations.

Straight Duplex Heat Exchanger Tubes

Straight seamless or welded tubes, where permitted by the applicable specification, for shell & tube heat exchangers and condensers.

Duplex U-Bend Tubes

Precision U-bend tubes for exchangers requiring customized straight-leg length, bend radius and project-specific inspection.

Parameters We Can Review

Tube OD · Wall Thickness · Straight-Leg Length · Bend Radius · Wall Thinning · Ovality · Heat Treatment · PMI / NDE · Customer Drawing

Long Length Duplex Tubes

Customized long-length duplex tubes for large heat exchanger bundles requiring specific project lengths and fewer joints.

Available length depends on grade, OD, wall thickness, manufacturing route and transportation requirements.

Duplex Finned Tubes

Enhanced-surface duplex tube solutions for project-specific heat-transfer requirements.

Available configurations can be reviewed according to base tube material, fin geometry and inspection specification.

Duplex Heat Exchanger Tube Specifications

Specification	Available Options
Material Grades	S31803 / S32205
Construction	Seamless / Welded
Outside Diameter	Standard & Customized
Wall Thickness	Average WT / Minimum WT
Length	Fixed / Random / Customized Long Length
Tube Form	Straight / U-Bend / Finned
Surface Condition	Annealed / Pickled / Project Requirement
Heat Treatment	According to applicable material specification
Inspection	PMI / ET / UT / Hydro / Dimensional / TPI
Documentation	MTC / EN 10204 3.1 / 3.2 / Inspection Reports

Common Duplex Tube Standards

ASTM A789 / ASME SA789

Seamless and welded ferritic/austenitic stainless steel tubing for general corrosion-resistant service.

EN 10216-5

Seamless stainless steel tubes for pressure purposes.

ASTM A790 / ASME SA790

Related specification for duplex stainless steel pipe, not the primary heat-exchanger tubing standard. ASTM identifies A790 as a seamless and welded ferritic/austenitic stainless steel pipe specification.

Duplex Heat Exchanger Tube Applications

Heat Exchanger Manufacturers

Duplex tube supply for heat exchanger fabrication, replacement bundles and demanding process equipment.

Refineries

Duplex tube materials for refinery heat-transfer equipment requiring increased strength and corrosion resistance.

Oil, Gas & Petrochemical

Tube solutions for process heat exchangers handling corrosive operating conditions.

Chemical Processing

Duplex heat exchanger tubes for aggressive process media and chemical equipment.

Desalination & Seawater

Duplex material options for selected heat exchanger applications involving chloride-rich service conditions.

Testing, Inspection & Documentation

ET

Eddy Current Testing

UT

Ultrasonic Testing

PMI

Positive Material Identification

Hydro

Hydrostatic Testing

Dimensional Inspection

OD / WT / Length

Documentation

Reports & Certificates EN 10204 3.1 / 3.2

Project Documentation Support

Complete documentation for seamless approvals and traceability.

Why DLSS for Duplex Heat Exchanger Tubes?

Duplex Material Expertise

Project support for S31803 and S32205 duplex tube requirements.

Minimum-Wall & Custom Sizes

Average-wall, minimum-wall, non-standard OD, WT and length requirements can be reviewed.

U-Bending Capability

Custom straight-leg length, bend radius and inspection requirements.

Inspection & Traceability

PMI, NDE, heat-treatment documentation and material traceability according to project requirements.

Urgent Project Support

Material availability, production route and inspection requirements can be reviewed for shutdown and replacement projects.

FAQ

What duplex grades does DLSS supply for heat exchanger tubes?

DLSS can review S31803 and S32205 duplex heat exchanger tube requirements according to the applicable product and project specifications.

What standard is commonly used for duplex stainless steel tubing?

ASTM A789 / ASME SA789 is a key specification covering seamless and welded ferritic/austenitic stainless steel tubing.

Is ASTM A790 a heat exchanger tube standard?

ASTM A790 is a ferritic/austenitic stainless steel pipe specification, so it is treated as a related piping standard rather than the main tubing standard on this page.

Can duplex tubes be supplied with minimum-wall requirements?

Minimum-wall requirements can be reviewed according to the applicable standard and purchase specification.

Can duplex tubes be supplied as U-bend tubes?

Yes. U-bend requirements can be reviewed according to grade, standard, OD, WT, straight-leg length, bend radius, heat treatment and inspection requirements.

What inspections can be arranged?

Depending on specification, inspection may include PMI, dimensional inspection, ET, UT, hydrostatic testing and third-party inspection.

Duplex Heat Exchanger Tube Technical Resources

S32205 Material Guide

Composition, properties, corrosion characteristics and heat exchanger applications.

ASTM A789 Tube Standard

Scope, tube manufacturing, wall requirements, heat treatment and inspection.

Stainless Steel vs Duplex

Compare conventional austenitic stainless steel and duplex materials for heat exchanger applications.

S32205 vs S32750

Understand when Duplex 2205 or Super Duplex 2507 may be considered.

PREN Explained

Understand how alloy chemistry relates to pitting resistance.