Pipe Coating, Lining & Cladding: Types Guide

Quick Reference

External coating: protects against soil/environment corrosion (FBE, 3LPE, 3LPP). Internal lining: protects against corrosive fluids (PTFE, epoxy, cement mortar). Cladding (CRA): bimetallic pipes with corrosion-resistant inner layer (Inconel, SS, Monel) bonded to carbon steel outer shell for cost optimization.

What is the difference between external pipe coating and internal pipe lining and cladding? External pipe coatings are used to protect the metal from corrosive environments (3LPE-coated pipes are the most common choice). Internal lining (for example PTFE) protects the pipe from corrosive fluids. Clad pipes (CRA or “Bimetallic Pipes”) have the inner surface covered by higher-grade materials to achieve stronger resistance while decreasing the overall pipe cost.

Externally Coated Pipes

Coated pipes, also known as pipe coatings, refer to steel pipes that have been treated with protective coatings to enhance their corrosion resistance, durability, and performance in various environmental and operating conditions.

These coatings are applied to the external and/or internal surfaces of pipes to provide protection against corrosion, abrasion, chemical attack, and other forms of degradation.

Externally coated pipesCoated pipes are commonly used in industries such as oil and gas, water distribution, construction, and infrastructure development. Here are some common types of coatings used for pipes:

Typical Coating Materials

Fusion-Bonded Epoxy (FBE)

FBE coatings are thermosetting epoxy powders applied to the external surface of pipes using electrostatic spray or fluidized bed deposition methods. Once applied, the coating is cured to form a tough, protective layer that resists corrosion and mechanical damage.

Three-layer polyethylene (3LPE)

3LPE coatings consist of a fusion-bonded epoxy primer, an adhesive layer, and a polyethylene topcoat. These coatings provide excellent resistance to corrosion, moisture, and mechanical stress, making them suitable for underground and underwater applications.

3LPE-coated pipes feature a three-layer polyethylene coating consisting of:

• a high-performance fusion bonded epoxy (FBE),
• a copolymer adhesive
• an outer layer of polyethylene which provides tough, durable protection against corrosion and erosion.

3LPE pipe suit medium to high operating temperatures.

Pro Tip

For buried pipelines above 80°C, specify 3LPP instead of 3LPE - polyethylene softens at elevated temperatures and can disbond from the pipe. For subsea applications with even higher temperatures, consider multi-layer polypropylene (MLPP) or FBE with thermal insulation.

(Source: Wasco Energy Youtube Channel)

Three-layer polypropylene (3LPP)

Similar to 3LPE coatings, 3LPP coatings consist of an epoxy primer, an adhesive layer, and a polypropylene topcoat. These coatings offer superior chemical resistance and higher operating temperatures compared to polyethylene coatings.

Coal Tar Enamel (CTE)

CTE coatings are solvent-based bituminous coatings applied to steel pipes by hot-dipping or wrapping methods. While less common than epoxy or polyethylene coatings, CTE coatings provide effective corrosion protection and can withstand high temperatures and abrasive conditions.

Polyurethane (PU)

PU coatings are solvent-based or powder coatings applied to pipes to provide abrasion resistance, chemical resistance, and UV stability. These coatings are often used in offshore and marine environments where high-performance coatings are required.

Other non-metallic pipe coatings

Paints, varnishes, lacquers, bituminous coatings, resins, plasticizers, Greases, waxes, oils, other plastics (Rilsan, PTFE, PVC), Elastomers (various types), Vitreous enamel, Cement mortar

Organometallic pipe coating

Paints pigmented with metals in powder form (aluminum, zinc, lead, stainless steel), Paints containing zinc ethyl-silicate

Chemical modification

Phosphating, Chromatin, phosphating, Black finishing, and browning

Cementation

Application of an external layer of cement to achieve physiochemical modification

Advantages/Disadvantages of Pipe Coating Materials

The main types of non-metallic pipe coating materials, and their advantages/disadvantages, are summarized in the table below:

Pipe Coating Type	Advantages	Disadvantages
Three-layer Polyethylene (3LPE) and 3 layers of Polypropylene (3LPP)	Low material and application cost	Application of flame risks workplace fires/explosions. Requires flame for adhesion. Limited heat resistance (max 225-250°F). Limited dimensional stability. Borderline hardness. Poor resistance to sulfur, amines, oxygen, and other oxidants.
Polypropylene (PUR)	Recommended for deep sea applications with relatively high temperatures and pressures	Polypropylene is liable to chain degradation from exposure to heat and UV radiation such as that present in sunlight.
Fusion Bonded Epoxy (FBE)	Excellent chemical resistance and great dimensional stability with minimized hysteresis	Rather expensive application cost per meter. FBE materials are expensive. The pipe and the coating materials must be heated to approx 250°F. Long lead times.
Asphalt enameled and polyurethane (PUR)	Cheap and superior to coal enamel. Reduces hysteresis. Fast treatment.	Modest resistance to chemical aggression. Strict temperature ranges. Limited dimensional stability.

External Pipe Coating: Benefits

Coated pipes offer several benefits, including:

Benefit	Description
Corrosion Protection	Coatings provide a barrier against corrosive substances, preventing the steel substrate from coming into contact with moisture, chemicals, and other corrosive agents.
Extended Service Life	Coated pipes are more durable and have a longer service life compared to uncoated pipes, reducing maintenance costs and downtime.
Improved Flow Efficiency	Internal coatings reduce friction and resistance, improving flow efficiency and reducing energy consumption in fluid transport systems.
Environmental Protection	Coatings help to prevent leaks, spills, and environmental contamination by maintaining the integrity of pipelines and preventing corrosion-related failures.

Overall, coated pipes are essential components in various industries where corrosion protection, durability, and performance are critical requirements for infrastructure and asset integrity.

Internally Lined Pipes

Lined pipes, also known as pipe liners, refer to steel pipes that have been internally lined with a protective layer or lining material to enhance their corrosion resistance, chemical resistance, and abrasion resistance. These linings are applied to the internal surface of pipes to protect the steel substrate from the effects of corrosive fluids, abrasive materials, and other harsh operating conditions. Lined pipes find applications in industries such as oil and gas, chemical processing, water treatment, and power generation.

Internally lined pipeLined pipes are fitted with an internal protective material which is mechanically inserted into the tubular section. The lining material is fitted into the pipe at the end of the manufacturing process. It is clear that internal lining materials, which have their own thickness, reduce the bore size of the pipe.

Common Mistake

Not accounting for lining thickness when sizing lined pipes for flow capacity. A 6” pipe with a 6mm PTFE lining has an effective ID closer to a 5” pipe. Always verify flow calculations use the lined ID, not nominal pipe size, especially in high-velocity services where pressure drop is critical.

Pipe Internal Lining Materials

Here are some common types of linings used for pipes:

1. Rubber Lining

• Rubber linings, typically made of natural or synthetic rubber compounds, are applied to the internal surface of pipes using vulcanization or bonding techniques.
• Rubber linings offer excellent resistance to corrosion, abrasion, and chemical attack, making them suitable for handling corrosive fluids, slurries, and abrasive materials.
• Rubber-lined pipes are commonly used in industries such as mining, mineral processing, and chemical processing, where aggressive environments are present.

2. Polymer Lining

• Polymer linings, such as polyethylene (PE) or polypropylene (PP), are applied to the internal surface of pipes using fusion-bonded or adhesive bonding methods.
• Polymer linings provide superior resistance to corrosion, chemical attack, and high temperatures, making them suitable for a wide range of applications in corrosive environments.
• Polymer-lined pipes are used in industries such as water and wastewater treatment, chemical processing, and semiconductor manufacturing, where chemical resistance and purity are essential.

3. Ceramic Lining

• Ceramic linings, composed of alumina, zirconia, silicon carbide, or other ceramic materials, are applied to the internal surface of pipes using adhesive bonding or thermal spray methods.
• Ceramic linings offer exceptional resistance to abrasion, erosion, and high temperatures, making them suitable for handling abrasive slurries and high-velocity flows.
• Ceramic-lined pipes are commonly used in industries such as mining, power generation, and pulp and paper processing, where severe abrasion and wear are encountered.

4. Glass Lining

• Glass linings, also known as vitreous enamel linings, are applied to the internal surface of pipes using a fritting process or glass-fused-to-steel technology.
• Glass linings provide excellent resistance to corrosion, abrasion, and chemical attack, as well as high temperatures and thermal shock.
• Glass-lined pipes are used in industries such as pharmaceuticals, food and beverage processing, and specialty chemicals, where cleanliness, purity, and corrosion resistance are critical requirements.

5. Other lining materials

• Teflon (PTFE)
• Cement mortar
• Liquid epoxy
• Fusion bonded epoxy (FBE)
• Bituminous asphalt
• Zinc

Internal Pipe Lining: Benefits

Lined pipes offer several benefits, including:

Benefit	Description
Corrosion Protection	Linings provide a protective barrier against corrosive fluids, preventing the steel substrate from coming into contact with corrosive agents.
Abrasion Resistance	Linings offer resistance to abrasive materials and erosive flows, extending the service life of pipes in high-wear applications.
Chemical Resistance	Linings resist chemical attacks from acids, alkalis, and other corrosive substances, ensuring the integrity of pipelines in aggressive environments.
Smooth Flow Characteristics	Some linings improve flow efficiency by reducing friction and resistance, minimizing pressure drop and energy consumption in fluid transport systems.

Overall, lined pipes are essential components in industries where corrosion protection, abrasion resistance, and chemical resistance are critical requirements for maintaining infrastructure integrity and operational reliability.

CLAD PIPES (CRA or Bimetallic Pipes)

Clad pipes, also known as bimetallic pipes or clad-lined pipes, are composite pipes that consist of a steel core or base material clad with a corrosion-resistant alloy layer on the external or internal surface. Clad pipes are also called CRA (which stands for “corrosion-resistant alloy”).

The cladding process consists of the application, in the inner part of the pipe, of a layer of higher-grade material onto a lower-grade base material of the pipe. Clad pipes are used for fluids that would quickly corrode carbon-manganese steels.

The bonding between the two materials is metallurgical and can be achieved by welding the two together or with explosion techniques (whereas lined pipes feature a mechanical bonding of different materials). These pipes combine the mechanical strength of steel with the corrosion resistance of alloy materials, offering enhanced performance and durability in corrosive environments.

Clad pipes are commonly used in industries such as oil and gas, chemical processing, and water treatment, where corrosion resistance and reliability are critical requirements.

Key Features of Clad Pipes

Here are some key features and types of clad pipes:

Structure and Construction

• Clad pipes typically consist of a steel core or base material, such as carbon steel or low-alloy steel, with a corrosion-resistant alloy layer bonded to one or both surfaces.
• The alloy layer is applied to the base material through various bonding methods, such as explosion bonding, roll bonding, diffusion bonding, or weld overlay techniques.
• The alloy layer may cover the entire surface area of the pipe (full clad) or only specific regions exposed to corrosive environments (partial clad).

Types of Cladding Materials

Material Category	Examples	Purpose
Corrosion-Resistant Alloys	Stainless steels (316L, 317L), nickel alloys (Alloy 625, Alloy 825), duplex stainless steels (UNS S31803, UNS S32205)	Resistance to corrosion, pitting, and stress corrosion cracking
Wear-Resistant Alloys	Hard-facing materials (e.g., tungsten carbide)	Resistance to abrasion and erosion in high-wear applications
High-Temperature Alloys	Alloy 800H, Alloy 625	Applications involving elevated temperatures and thermal cycling

Benefits of Clad Pipes

Benefit	Description
Corrosion Resistance	Superior resistance to corrosion, pitting, crevice corrosion, and stress corrosion cracking compared to conventional steel pipes, extending service life in aggressive environments.
Cost-Effectiveness	Provides corrosion resistance without the need for expensive solid alloy materials.
Flexibility and Versatility	Can be tailored to specific application requirements by selecting appropriate cladding materials and thicknesses, offering flexibility in design and performance optimization.
Enhanced Performance	Combines the mechanical properties of steel with the corrosion resistance of alloy materials, providing reliability in demanding operating conditions.
Reduced Maintenance	Requires less maintenance and downtime compared to solid alloy pipes, resulting in cost savings and improved operational efficiency over the lifecycle of the pipeline.

Applications

Clad pipes are widely used in various industries and applications, including offshore oil and gas production, chemical processing plants, refineries, desalination plants, and power generation facilities.

They are employed in applications such as subsea pipelines, process piping, heat exchanger tubing, reactor vessels, and sour service environments where corrosion resistance and reliability are critical requirements.

A clad pipe combines the strength and toughness of a carbon steel pipe with the corrosion resistance of a stainless or duplex pipe (or even higher grades, such as nickel high-alloyed materials like Inconel, Incoloy, etc).

Pipe cladding is used to enhance the durability and the resistance to corrosion of a pipe while keeping its final costs at acceptable levels. Of course, clad pipes are more expensive than lined pipes, as the overlay materials used are, generally, noble metals.

In summary, clad pipes offer a reliable and cost-effective solution for achieving corrosion resistance in corrosive environments, combining the mechanical strength of steel with the corrosion resistance of alloy materials to meet the demanding requirements of various industries and applications.

Field Note

Welding CRA-clad pipes requires special procedures - the root pass uses filler metal matching the cladding (e.g., Inconel 625 for Inconel clad), while the fill and cap may use different consumables. Always develop a qualified WPS for clad pipe joints and verify cladding continuity with PT after welding.

Suppliers Of Pipe Coating/lining/cladding Services

Pipe Coating Suppliers

Several companies specialize in providing pipe coating services for various industries, including oil and gas, water distribution, infrastructure, and construction. These companies offer a wide range of coating solutions to protect steel pipes from corrosion, abrasion, and other forms of degradation.

Supplier	Coating Services
Shawcor Ltd.	Global leader in pipeline coating and corrosion protection. Offers FBE, 3LPE, 3LPP, and concrete weight coating (CWC) for onshore and offshore pipelines.
Bredero Shaw	Division of Shawcor Ltd., specializing in oil and gas pipeline coating. Offers FBE, 3LPE, 3LPP, internal flow efficiency coatings, and custom solutions.
Consolidated Pipe & Supply Company	FBE, 3LPE, and internal coatings for water transmission, wastewater treatment, and industrial pipelines.
Bayou Companies	Subsidiary of Primoris Services Corporation. Offers FBE, 3LPE, 3LPP, and internal coatings for pipelines, risers, and subsea infrastructure.
Tnemec Company, Inc.	High-performance coatings including epoxy, polyurethane, and fluoropolymer coatings for harsh environmental conditions and chemical exposure.
Blastech Rail Services Inc.	FBE, 3LPE, and 3LPP coatings for transportation, infrastructure, and industrial sectors, including pipelines and structural steel.
Axalta Coating Systems	Epoxy, polyurethane, and thermoplastic coatings designed for corrosive environments and long-lasting protection.
Denso North America Inc.	Corrosion prevention and sealing systems including petrolatum tapes, wax tapes, and heat-shrink sleeves for pipelines and infrastructure.
Vestas Industrial Coating Solutions	FBE, 3LPE, and internal coatings for oil and gas, water, and wastewater industries, including pipelines, tanks, and vessels.
International Paint	Subsidiary of AkzoNobel. Epoxy, polyurethane, and zinc-rich coatings, plus specialty coatings for offshore and marine applications.

These are just a few examples of companies that offer pipe coating services. It’s essential to choose a reputable and experienced supplier that can provide high-quality coatings tailored to your project requirements and environmental conditions.

Pipe Lining Suppliers

Several companies specialize in providing pipe lining services to protect steel pipes and enhance their performance in various industries. These companies offer a range of lining solutions to prevent corrosion, abrasion, and other forms of degradation.

Supplier	Lining Services
U.S. Pipe	Cement mortar lining (CML) and polyurethane lining for water and wastewater applications.
T. D. Williamson	Pipeline maintenance and rehabilitation. CML, epoxy lining, and polyurethane lining to protect against corrosion and extend pipeline service life.
Sauereisen	Corrosion-resistant epoxy and vinyl ester lining systems for steel and concrete substrates in harsh environments.
Pipeline Linings Pty Ltd	CML, epoxy lining, and polyurethane lining for water, wastewater, and industrial pipeline rehabilitation.
Reline Group	Trenchless pipe rehabilitation including CIPP lining, spray lining, and epoxy lining for sewer, stormwater, and pressure pipelines.
AP/M Permaform	Trenchless rehabilitation with spiral-wound pipe lining systems (PVC, HDPE, fiberglass liners) for municipal and industrial applications.
National Linings Systems	Epoxy, polyurethane, and hybrid lining systems for tanks, pipes, and secondary containment areas.
Inliner Technologies	CIPP lining solutions using resin-impregnated liners for sewer and stormwater pipeline rehabilitation.
PICA Corporation	Pipeline inspection, assessment, and rehabilitation including robotic CML and epoxy lining for water, wastewater, and oil and gas pipelines.
Interplastic Corporation	Vinyl ester, epoxy, and polyester lining systems for industrial corrosion protection of steel and concrete substrates.

These are just a few examples of companies that offer pipe lining services. It’s essential to choose a reputable and experienced supplier that can provide high-quality lining solutions tailored to your project requirements and environmental conditions.

Pipe Cladding Suppliers

Pipe cladding services involve applying a layer of corrosion-resistant alloy onto the external or internal surface of steel pipes to enhance their durability and performance in corrosive environments. Several companies specialize in providing pipe cladding services for various industries, including oil and gas, chemical processing, and power generation.

Supplier	Cladding Services
Bodycote Surface Technology	Thermal spray coatings (metal alloy and ceramic coatings) to protect steel pipes from corrosion, wear, and erosion.
Hertel GmbH	Overlay welding services using corrosion-resistant alloys to protect steel pipes in aggressive environments.
Stork Technical Services	Weld overlay cladding using nickel alloys, stainless steel, and other corrosion-resistant alloys for pipelines and process equipment.
Vallourec	Metallurgical bonding techniques (explosion bonding, roll bonding) to apply corrosion-resistant alloy layers for offshore and onshore applications.
SANDVIK Group	Weld overlay cladding using advanced welding technologies and corrosion-resistant alloys for pipelines and components.
GAS Arabian Services	Overlay welding techniques to apply corrosion-resistant alloys onto steel pipes for upstream and downstream oil and gas applications.
Cor-Pro Systems, Inc.	Thermal spray coatings, weld overlay cladding, and corrosion inhibitors for protection against corrosion, erosion, and chemical attack.
Diamond Offshore Services	Weld overlay cladding using high-performance alloys for subsea pipelines and risers.
MetalTek International	Overlay welding and thermal spray coatings using corrosion-resistant alloys for harsh environments.
Ferroglobe PLC	Metallurgical bonding techniques for corrosion-resistant alloy layers on steel pipes for chemical processing and petrochemical applications.

These are just a few examples of companies that offer pipe-cladding services. It’s essential to choose a reputable and experienced supplier that can provide high-quality cladding solutions tailored to your project requirements and environmental conditions.

Related Articles

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• ASTM Materials for Stainless/Duplex Pipes - Corrosion-resistant pipe materials
• Nickel Alloy Pipes - Cladding materials: Inconel, Hastelloy
• Types of Pipes: Seamless and Welded - Manufacturing processes for coated pipes
• Corrosion Types and Prevention - Why coating and cladding are essential