Bimetal Composite Pipes

1 Product Definition

Bimetal Composite Pipes (also known as bimetallic clad pipes) consist of:

Outer Pipe (Base Material): Carbon steel or low-alloy steel for pressure bearing and structural strength

Inner Liner (Cladding Layer): Corrosion-resistant alloy bonded metallurgically or mechanically to the base pipe

This structure significantly extends service life while reducing material cost compared with solid alloy pipes.

2 Material Combinations (Typical)

Outer Pipe (Base Material)

Carbon Steel: ASTM A106 Gr.B, ASTM A53, API 5L Gr.B / X42–X65

Alloy Steel: ASTM A335 P11 / P22 / P91

Inner Liner (Cladding Material)

Stainless Steel: 304 / 304L / 316L / 317L / 321 / 347

Duplex Stainless Steel: 2205 / 2507

Nickel Alloys:

Alloy 625 (UNS N06625)

Alloy 825 (UNS N08825)

Hastelloy C276 (UNS N10276)

Monel 400 (UNS N04400)

3 Applicable Standards

ASTM A265–Specification for Steel-Clad Stainless Steel Plate

ASTM A263 / A264–Stainless Steel Clad Plate

API 5LD–Lined Pipe

ASTM A106 / A53 / A335–Base Pipe Standards

ASTM A240 / A312 / A790–Cladding Materials

ASME Section IX–Welding Requirements

Bimetal Composite Pipes

Outer Diameter (OD): 21.3 mm–1422 mm (1/2” –56”)

Wall Thickness (Total): 3 mm–60 mm

Cladding Thickness: 1.0 mm–5.0 mm (customized)

Length:Random Length, Fixed Length, Customized Cut Length

Bimetal (bi-metal) clad pipes are widely used in industries where severe corrosion, high pressure, high temperature, or wear conditions exist. By combining a corrosion-resistant inner liner with a high-strength carbon or alloy steel outer pipe, bimetal clad pipes offer an economical and high-performance alternative to solid alloy pipes.

Crude oil and natural gas often contain corrosive components such as H₂S, CO₂, and chloride ions, especially in subsea and unprocessed oil & gas fields, where internal corrosion is extremely severe. Using solid stainless steel or nickel alloy pipes for long pipelines is not cost-effective.

Bimetal clad pipes provide an ideal solution:

Inner liner (0.5–3.0 mm): Corrosion-resistant alloy in contact with the medium

Outer pipe: Carbon steel or low-alloy steel for pressure resistance

Typical material selection:

CO₂environment: 316L austenitic stainless steel

CO₂+ low chloride: 2205 / 2507 duplex stainless steel

H₂S + CO₂+ chloride:

Alloy 625, Alloy 825, Alloy 028, Alloy G3 (nickel-based or Fe-Ni alloys)

Extreme corrosion: Titanium alloy liners

Outer pipe materials:

API 5L X42 / X50 / X60 / X70

ASTM A106 Gr.B

ASTM A335 P22

The API 5LD standard governs bimetal clad pipes for oil & gas pipelines, covering materials such as Cr-Mo steel, Super 13Cr, Alloy G3, Alloy 028, Alloy 825, and other nickel-based cladding alloys.

Superheater tubes in supercritical and ultra-supercritical boilers must operate under:

Temperatures up to 650°C

Steam pressure up to 35 MPa

Strong resistance to steam oxidation and high-temperature corrosion

Typical bimetal structure:

Outer pipe: SUS310S, 35Cr-55Ni, 40Cr-55Ni

Inner liner: Alloy 800, 17-14CuMo

Womic Stainless Steel supplies bimetal superheater cladding tubes that meet these demanding conditions.

International suppliers such as Sandvik (Sweden) have also successfully applied similar composite pipes without changing boiler structural designs.

Waste incineration environments are characterized by:

High temperatures

Chlorine-rich flue gases

Severe corrosion and oxidation

Bimetal clad pipes for incinerators typically use:

Outer pipe: Sanicro 65 or high-alloy materials

Inner pipe: Carbon steel or Cr-Mo steel with resistance to stress corrosion cracking

Since their first application in 1971, more than 2 million meters of cladding pipes have been installed in incinerator superheaters and water wall tubes across Europe and North America.

Heat exchanger tubes require:

Good thermal conductivity

Adequate mechanical strength

Excellent corrosion resistance

Typical bimetal configurations:

Inner pipe: Alloy 800 (Ni-Cr alloy)

Outer pipe: ASTM A213 T2 low-alloy steel

Examples include:

Sandvik: Alloy 800 inner + A213 T2 outer

NKK (Japan): NIC42 inner + API 5L-16MnV outer

Bimetal clad pipes are also used where abrasion and erosion are critical concerns.

Example:

Outer pipe: SUS316L stainless steel

Inner liner: Stellite No.12 alloy

Such pipes have shown excellent performance in pneumatic conveying systems for fine powders, with service life exceeding 4 years without significant wear.

Marine applications demand resistance to:

Seawater corrosion

Biofouling

Chloride stress corrosion cracking

Typical structure:

Inner liner: Nickel alloy, titanium alloy, stainless steel, or copper alloy

Outer pipe: Carbon steel or low-alloy corrosion-resistant steel

Bimetal clad pipes are widely used for:

Marine heat exchangers

Seawater desalination systems

Seawater intake pipelines

Japanese manufacturers such as Kawasaki have applied these pipes extensively.

Bimetal composite pipes are increasingly used in high-end civil and municipal systems, including:

Cold & hot water pipelines

Direct drinking water pipes

District heating systems

Solar energy & ground-source heat pump pipelines

Commercial and residential building water supply

HVAC circulation systems

Bimetal clad pipes are widely used across multiple industries:

Oil & gas pipelines and casing pipes

Chemical heat exchanger tube bundles

Power plant desalination & desulfurization pipelines

Metallurgy & mining

Pharmaceutical & chemical processing

Wastewater treatment

1. Superior Wear Resistance and Hardness

The super-hard wear-resistant alloy used for the inner lining achieves a hardness greater than 56 HRC, providing excellent abrasion resistance, erosion resistance, and thermal stability, even under severe service conditions involving solid particle impact and high flow velocity.

2. Excellent Impact Resistance and Metallurgical Bonding

The KMTBCr28 bimetal composite wear-resistant elbow features a fully metallurgical bond between the inner wear-resistant alloy layer and the outer steel pipe.

This ensures:

High structural integrity

Safe and reliable performance

No delamination under impact or vibration

The thermal expansion coefficients of the two materials are closely matched, effectively preventing cracking, peeling, or separation during thermal cycling. The outer layer is a steel pipe for strength, while the inner lining is a super-hard wear-resistant alloy.

3. Outstanding Heat and Corrosion Resistance

The matrix of the super-hard alloy material exhibits strong resistance to high temperatures and corrosive media.

In wet environments with corrosive media and particle scouring, corrosion-resistant super-hard alloys are preferred.

In dry abrasive environments, where wear is the dominant failure mechanism, specially heat-treated ultra-hard wear-resistant alloys are selected to maximize service life.

4. Advanced EPC Casting Process with Stable Quality

The bimetal wear-resistant pipes are manufactured using an internationally advanced EPC (Expendable Pattern Casting) process, offering:

High casting yield

Excellent compactness

Uniform lining thickness

Stable and consistent product quality

This process ensures a low composite cost while maintaining high performance and reliability.

5. Easy Installation, Connection, and Maintenance

Bimetal wear-resistant pipes and elbows support multiple connection methods, including:

Flange connection

Quick coupling

Direct welding

Thanks to their high impact strength and mechanical toughness, the pipes can be hammered or knocked during maintenance to clear partial blockages without damaging the structure.

They can also be cut, removed, welded, and reinstalled on-site, providing excellent flexibility for installation and system modification.

Professional Bimetal Composite Pipe Manufacturer

Wide range of base materials & cladding alloys

Strict metallurgical bonding quality control

Compliance with ASTM / ASME / API / EN standards

Cost-effective alternative to solid alloy pipes

Strong export experience to Middle East, Europe, Southeast Asia

Custom engineering solutions & fast technical support

Base Pipe & Cladding Material Preparation

Surface Cleaning & Machining

Composite Forming (Hot Roll Bonding / Explosion Bonding / Mechanical Lining)

Heat Treatment & Stress Relieving

Straightening & Sizing

Non-Destructive Testing (UT / ECT)

Final Inspection & Marking

Export Packing

Plastic caps on both pipe ends

Inner liner protection

Wooden cases / steel frames

Bundled with steel strips

Seaworthy export packing

Customized marking & barcoding available

Shipping Methods:

Sea Freight (FCL / LCL)

Air Freight (urgent orders)

Delivery Terms:

FOB / CFR / CIF / DDP

Main Ports:

Shanghai, Ningbo, Tianjin

Email:  info@womicstainless.com

Website: www.womicstainless.com

Contact Womic Stainless today for bimetal composite pipe pricing, technical datasheets, project support, and customized solutions. Our experienced team will respond within 24 hours.