How Does Polyken Pipeline Tape Protect Steel From Corrosion?

Buried steel pipelines are exposed to soil conditions that can cause corrosion if the steel is not adequately protected.

Moisture, dissolved salts, oxygen, and other environmental factors can contribute to electrochemical corrosion reactions at exposed steel surfaces.

For decades, pipeline operators have used external protective coatings to separate steel from its surrounding environment.

One established technology is Polyken pipeline tape, a family of coating systems that uses polymer backings and specially formulated adhesives to provide external corrosion protection.

Unlike ordinary adhesive tape, Polyken pipeline coating systems are engineered for industrial pipeline applications, including new construction, rehabilitation, and certain field joint coating projects.

Understanding how these systems work requires examining the individual components.

What Is a Polyken Pipeline Tape Coating System?

Polyken manufactures several pipeline coating systems designed for different operating conditions and applications.

Many use a combination of polyethylene backing materials and butyl rubber-based adhesives.

One example is the Polyken 980/955 coating system, which consists of three primary components:

1. Polyken 1019 or 1027 liquid adhesive primer

2. Polyken 980 corrosion protection innerwrap

3. Polyken 955 mechanical protection outerwrap

Each component serves a different purpose.

The primer prepares the steel surface for bonding, the innerwrap provides the principal corrosion protection barrier, and the outerwrap provides additional mechanical protection.

These components are designed to function together as a complete coating system.

Step 1: The Primer Establishes Contact With the Steel

Before applying Polyken tape, the pipe must be prepared according to the manufacturer's requirements.

Surface preparation removes contaminants that could interfere with coating adhesion.

For the 980/955 system, Polyken identifies two compatible liquid adhesives:

Polyken 1019: Designed for machine application.

Polyken 1027: Designed for brush application.

These primers promote adhesion between the prepared pipe surface and the corrosion protection tape.

They also provide a smooth contact surface and contribute to the corrosion protection system.

This is important because the performance of a tape coating depends on more than the tape itself.

Poor surface preparation or improper primer application can compromise the finished coating.

Step 2: Polyken 980 Provides the Primary Corrosion Barrier

Polyken 980 is the anti-corrosion innerwrap in the 980/955 system.

It combines a polyethylene backing with a thick butyl rubber-based adhesive layer.

The adhesive is designed to bond to the properly primed steel surface.

The polyethylene backing contributes to the coating's barrier properties.

Together, these materials help prevent water and other environmental substances from reaching the steel.

The innerwrap is spirally applied around the pipe, with each turn overlapping the previous turn.

Correct overlap is essential to achieving continuous coating coverage.

The required overlap must follow the applicable installation specification.

Step 3: Polyken 955 Provides Mechanical Protection

Once the corrosion protection innerwrap is installed, Polyken 955 is applied over it.

Polyken 955 is the mechanical protection outerwrap.

Its construction includes a polyethylene backing and an adhesive layer designed to bond to the innerwrap.

The outerwrap helps protect the corrosion barrier against damage during:

• Pipe handling

• Transportation

• Installation

• Lowering into trenches

• Backfilling

In the standard 980/955 system, the Polyken 980 innerwrap is black, while the Polyken 955 outerwrap is white.

This color difference helps installers distinguish the two layers.

The distinction between their functions is important.

Polyken 980 provides the primary corrosion protection, while Polyken 955 supplies the principal mechanical protection layer.

Why Is Butyl Rubber Used in Pipeline Tape?

Butyl rubber-based adhesives are useful in pipeline coating systems because they provide adhesion and flexibility.

These characteristics allow the coating to conform to the pipe surface while maintaining a protective barrier.

The adhesive must remain effective under the operating conditions for which the coating system is designed.

However, not all Polyken adhesives are identical.

Different Polyken tape systems use different adhesive formulations and backing constructions to meet particular application requirements.

Contractors should not assume that one Polyken tape can automatically replace another.

How Does Polyken Tape Prevent Moisture From Reaching Steel?

The principal corrosion protection mechanism is barrier protection.

When properly applied, the tape coating system limits the movement of moisture and other corrosive substances toward the steel.

Several characteristics contribute to this protection:

Adhesion

The adhesive helps maintain contact between the coating and the substrate.

Low Permeability

The polymer backing and adhesive system limit the transmission of water and other substances.

Continuous Coverage

Proper spiral overlap creates a continuous protective coating around the pipe.

Mechanical Protection

The outerwrap helps prevent installation damage that could compromise the corrosion protection layer.

These characteristics work together.

A strong adhesive cannot compensate for missing coating coverage, and a mechanically durable outerwrap cannot fully protect steel if the underlying corrosion barrier is improperly installed.

Why Does Tape Overlap Matter?

Pipeline tape is generally applied in a spiral pattern.

Each revolution overlaps the preceding wrap.

The overlap determines how much of the pipe is covered by multiple layers of tape.

It also affects the amount of material required.

For example, a 50% spiral overlap creates approximately two layers of coverage across the main wrapped area.

However, 50% overlap is not a universal requirement for every Polyken product.

Some systems specify different overlap dimensions for the innerwrap and outerwrap.

For the Polyken 980/955 system, the manufacturer's application instructions call for at least a 1-inch overlap for both tape layers.

Contractors should always follow the requirements for the specific system being installed.

What Happens If Pipeline Tape Is Applied Incorrectly?

Even a well-designed coating system can experience problems if installation requirements are not followed.

Potential issues include:

Poor surface preparation: Contamination can interfere with adhesion.

Incorrect primer application: Applying too much or too little primer, or failing to follow the manufacturer's application instructions, can prevent the Polyken tape from bonding properly to the steel surface.

Insufficient overlap: Inadequate overlap can compromise coating continuity.

Wrinkles or trapped air: Improper wrapping can create areas of poor contact.

Incorrect tape tension: Uneven application tension can affect coating geometry and adhesion.

Mechanical damage: Improper handling or backfilling can damage the coating after installation.

These are reasons why application procedures and inspection requirements are essential parts of pipeline corrosion protection.

Where Is Polyken 980/955 Used?

According to the manufacturer's product literature, Polyken 980/955 is intended for several applications.

New Pipeline Construction

The system can be used to protect steel pipelines during new construction projects.

Pipeline Rehabilitation

Polyken 980/955 can be applied to existing pipelines during coating rehabilitation work.

Plant Piping

The system is also identified for industrial plant piping applications.

Large-Diameter Bends and Fittings

The tape's conformability allows it to be considered for certain bends and fittings where coating geometry can be challenging.

The selected application method and coating specification must be appropriate for the project.

Are All Polyken Pipeline Tapes the Same?

No.

Polyken offers different tape products and systems for different requirements.

Examples include:

• Polyken 930 series innerwrap products

• Polyken 954 mechanical protection outerwrap

• Polyken 955 mechanical protection outerwrap

• Polyken 980 anti-corrosion innerwrap

• Polyken 1019 and 1027 liquid adhesive primers

These materials should be selected according to the specified coating system.

A product used for one type of pipeline coating application may not be suitable for another.

Operating temperature, installation conditions, mechanical protection requirements, and the applicable specifications all affect product selection.

Can Polyken Tape Be Applied by Hand or Machine?

Depending on the selected Polyken system and project requirements, pipeline tapes can be applied manually or using specialized wrapping equipment.

Machine application can be useful for longer pipe sections or projects requiring consistent wrapping conditions.

Hand application may be appropriate for certain field joints, fittings, repairs, or limited-access areas.

The important consideration is achieving the specified overlap, tension, adhesion, and coating coverage.

The manufacturer's installation requirements should determine the appropriate method.

Polyken Tape and Cathodic Protection

Buried steel pipelines frequently use both external coatings and cathodic protection.

The coating limits exposure of the steel to the surrounding environment.

Cathodic protection provides an additional corrosion control measure at exposed steel locations.

Coating systems must be evaluated for their compatibility with cathodic protection, including properties such as adhesion and resistance to cathodic disbondment.

The performance of one Polyken tape system should not automatically be assumed to apply to every other Polyken product.

Selecting Polyken Tape for Your Pipeline Project

Before ordering Polyken tape, contractors should identify the actual project requirements.

Useful information includes:

• Pipe outside diameter

• Total length requiring coating

• New construction or rehabilitation

• Existing coating type

• Operating temperature

• Surface preparation requirements

• Specified primer, innerwrap, and outerwrap

• Application method

• Required tape overlap

These details help determine which Polyken materials are appropriate and how much material will be required.

Polyken Pipeline Tape From Joint Specialists Inc.

Joint Specialists Inc. works with pipeline contractors and industrial customers on corrosion protection material requirements.

Whether your project involves Polyken innerwrap, outerwrap, primer, or a complete pipeline tape coating system, JSI can assist with product inquiries and quotations.

Steve Simpson
Joint Specialists Inc.
Phone: 936-321-3333
Email: steve@jsicoatings.com

For a Polyken quotation, provide your pipe diameter, coating length, specified Polyken products, and estimated project quantities.

We welcome the opportunity to assist with your next pipeline coating project.