A Game-Changer in the Field: The Introduction of Wraparound Shrink Sleeves

 

Let’s set the scene: it’s the mid-1970s, and we’re heading to Bakersfield, California—right in the heart of pipeline country. At this point in time, the industry is on the verge of a meaningful shift with the introduction of a new solution: the wraparound shrink sleeve, commonly referred to as WPC.

At first glance, it might not sound revolutionary. But for contractors working in the field, this innovation was a big deal.

Flexibility Comes to the Jobsite

Prior to wraparound sleeves, field joint coatings often required pre-installed tubular sleeves. That meant planning ahead—sometimes far ahead—and physically sliding those sleeves down long sections of pipe to reach the weld joint. As you can imagine, that wasn’t always practical.

With the introduction of wraparound shrink sleeves, contractors suddenly had flexibility. They could complete their welds first and then return later to apply the coating. This was especially valuable in real-world conditions, where field joint coatings are frequently ordered at the last minute. Instead of scrambling or working around logistical headaches, crews could simply bring the material to the weld and install it on the spot.

In short, it made life a whole lot easier.

Built to Perform

Early versions of these sleeves looked a bit different than what you’ll see today—some even featured a bold “RAYCHEM” print across the closure. But while the appearance has evolved, the core technology has remained remarkably consistent.

At the heart of the system is a high-shear adhesive designed to bond quickly and securely to polyethylene (PE) surfaces. Even under elevated temperatures, the adhesive maintains its grip—an essential characteristic for pipeline integrity.

Over time, enhancements were made to improve performance even further. One key addition was the incorporation of a fiber mesh within the closure, providing extra strength to resist the forces generated by high-shrink materials. These refinements helped ensure reliability across a wider range of conditions.

Expanding the Possibilities

The introduction of WPC didn’t just solve a logistical problem—it opened the door to an entire family of solutions. With this new format, manufacturers like Raychem were able to expand their product offerings to address a variety of applications, operating temperatures, and environmental challenges.

What started as a practical innovation in the field quickly became a foundational technology, shaping the way pipeline coatings would be applied for decades to come.

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From a modern perspective, it’s easy to take wraparound sleeves for granted. But back in the 1970s, this was a pivotal moment—one that brought much-needed flexibility, efficiency, and performance to pipeline construction and maintenance.

Raychem History: GRS

 Tiptoeing Through History: Raychem’s GRS Sleeve in Stockton, CA (1975)

This week’s opportunity to tiptoe through history takes us back to Stockton, California, in 1975—a time when Raychem was grappling with a problem that was equal parts challenging and dangerous.

The issue? A leaking bell-and-spigot natural gas line.

That alone is serious enough. But this leak wasn’t out in the middle of nowhere. It was downtown—surrounded by buildings, roads, and plenty of traffic. Shutting everything down and replacing the line wasn’t always an option, so the question became: How do you safely stop a gas leak and permanently repair it in place?

Somewhere inside Raychem’s R&D group, a solution began to take shape. Looking back today, it’s a fascinating mix of caution, ingenuity, and confidence in their technology.

Here’s how the process worked.

First, crews would excavate and expose the leaking gas line. No shortcuts here—you had to clearly see what you were dealing with.

Next came the delicate part. Using a brass hammer and lead wool (chosen specifically to avoid sparks), the crew would carefully hammer the lead wool into the leaking area in an attempt to temporarily stop the gas flow.

Once that was done, soapy water was sprayed on the area to confirm the leak had been stymied. No bubbles meant it was time to move forward.

Cleaning the pipe was next—but again, safety was paramount. Surface preparation had to be done without introducing sparks. That meant sand blasting or using air-driven tools, such as a brass needle descaler.

With the surface as clean as conditions allowed, the GRS shrink sleeve was wrapped into place and secured using Raychem’s rail and channel system.

And then came the part that still makes people raise an eyebrow today…

Open flame.
Once everything was in position, the torch came out and the sleeve was shrunk down onto the pipe, forming a tight, sealed repair.

It sounds a little crazy when you read it now—open flame on a gas line in a busy downtown area—but the reality is this: GRS was an extremely successful product. Over its lifetime, it generated multi-millions of dollars in sales and was widely accepted as a reliable solution for this exact problem.

If memory serves, the GRS product line began to fade out in the late 1980s or early 1990s, giving it a solid 15+ year run in the field. That’s no small achievement, especially considering the demanding and hazardous applications it was designed to address.

Next week, we’ll revisit GRS once again—but this time, we’ll be heading to Puerto Rico for another chapter in its story.

Shrink Sleeves for Water Pipe

 Covalence Waterwrap: A Proven Solution for Large Diameter Water Pipelines

If you work with large diameter water pipelines, chances are you’re already familiar with Covalence® Waterwrap. Originally introduced under the Raychem name, later part of Seal For Life, and now within the Henkel family of products, Waterwrap has built a long-standing reputation in the water pipeline industry.

Waterwrap is widely recognized as one of the premier solutions for protecting girth welds on large diameter water lines. Coating these welds is often one of the more challenging aspects of pipeline construction—especially as pipe diameters increase. Consistency, reliability, and long-term performance are critical, and Waterwrap has been meeting those demands for decades.

One of the key advantages of Waterwrap is its availability in thicknesses robust enough to allow welding after backfill. This capability can be a major benefit on projects where construction sequencing or site constraints make traditional approaches more difficult.

In addition, Waterwrap is compatible with all major factory-applied coatings, including PE- and PP-based systems. That versatility makes it an easy fit into a wide range of pipeline specifications without requiring compromises or special transitions.

With a proven track record, broad coating compatibility, and features designed specifically for large diameter water pipelines, Covalence Waterwrap remains a product well worth considering—especially if you haven’t evaluated it recently.

 A Trip Down Memory Lane: Raychem’s Relentless Pursuit of “Better Than Good Enough”

For this week’s trip down memory lane, we’re heading back to Des Moines, Iowa — September 1974.

Last week, I shared the results of a Raychem product evaluation involving a shrink sleeve applied to corrugated pipe. The verdict? It didn’t go particularly well.

But if there’s one thing Raychem was known for, it was thoroughness. When a company invests a significant portion of its revenue into research and development, it doesn’t walk away from a challenging application after a single setback. Quite the opposite.

So the story continues.

This time, Raychem evaluated whether a heat-shrink sleeve could successfully seal a simple corrugated pipe connection. By most accounts, the results were… okay.

And that was the problem.

“Okay” was never the goal. In fact, good enough was never good enough in Raychem’s world. If a product didn’t meet the high standards Raychem was known for in the marketplace, it simply wasn’t acceptable—regardless of whether it technically worked.

That relentless mindset—pushing past acceptable and striving for truly dependable solutions—is a big reason Raychem became the industry leader it was. And thankfully, that same philosophy still lives on today within the Henkel family of companies.

Because real innovation isn’t about settling. It’s about learning, improving, and refusing to compromise—especially in demanding, real-world applications.

Up next week: heat-shrinkable sleeves used to repair leaking gas lines. You won’t want to miss it.

Thursday Flashback: When R&D Teaches the Hardest (and Most Valuable) Lessons

 

After a brief holiday break, our Thursday Flashbacks are back — and this one takes us all the way to July of 1973.

At that time, Raychem was working to solve a challenging problem: how to effectively protect corrugated steel pipe from water ingress and corrosion. Their approach was ambitious. Engineers developed a heat-shrink sleeve with an exceptionally thick mastic layer and even packed additional mastic into the ridges of the corrugated pipe, aiming to create a truly waterproof barrier.

On paper, it seemed promising.

However, anyone familiar with shrink sleeves understands a fundamental limitation when it comes to corrugated surfaces. Shrink sleeves naturally tend to “bridge” across the peaks of corrugation. When that happens, a spiral leak path is left behind in the valleys — exactly where water is most likely to travel.

Despite extensive evaluations and testing, the solution simply didn’t perform as intended. Ultimately, the entire project was scrapped.

And that’s where the real value of this story lies.

Raychem devoted a significant portion of its revenue to internal research and development. When you invest millions of dollars into R&D, not every project will become a market success. Some efforts result in breakthrough products. Others fall into a different category: not a great product — but a great lesson.

This 1973 experiment was one of those moments. While the product never made it to market, the insights gained helped shape future technologies and reinforced an important truth in our industry: understanding why something doesn’t work can be just as valuable as finding something that does.

Sometimes progress comes not from success, but from the lessons learned along the way.

Temperature Ratings for Covalence/Raychem Heat Shrink Sleeves

 Temp Ratings for Covalence / Raychem Heat Shrink Sleeves for Corrosion Prevention

     I've found that often conversations about the product are more valuable than simply looking at a website.  I'd love to chat with you about this:  Steve 936/321-3333

    But now, looking at the various maximum temperature ratings for various Covalence / Raychem shrink sleeves:  we are basing these on maximum operating temperature of the pipeline.  In many cases, a pipeline project may list something like "maximum design temperature" and "expected operating temperature".  Very often, coatings are selected that will be able to meet the "maximum design temperature."  Occasionally, a client of ours will direct us to ignore 'max design' and instead quote based on "expected."  That is their choice of course.  

     So from here, I'm looking specifically at the flip side:  what is the maximum operating temperature of a pipeline with specific regard to our coatings (which is actually based almost wholly on the ratings of the adhesive used on that coating. 

WPCT - 140F

WPC65M - 150F

WPC100M - 176F (212F offshore or under insulation)

WPC120 - 251F

HTLP60 - 140F

HTLP80 - 176F

TPS - 140F

    To reiterate:  conversations about your project are MUCH BETTER than simply plugging in something you've read; so please call me to discuss!!

Heat Shrink Sleeves: Essential Information for Accurate Quoting

Want help? Contact: steve@jsicoatings.com

In the realm of purchasing and procurement, field joint coatings often find themselves at the tail end of the decision-making process. These coatings, while crucial, are frequently addressed in the eleventh hour, resulting in a significant portion of our orders falling under the "emergency" or "hot tail gate rush" category. At Joint Specialists, we understand this reality and strive to provide timely and reliable solutions.

As a distributor of Raychem products, we take pride in our ability to ship 95% of orders on the same day they are received, even under urgent circumstances. However, even for these expedited requests, we require some fundamental information to ensure the proper recommendation and pricing of our heat shrink sleeves. While obtaining the Field Joint Coating Specification makes our job significantly easier, it often involves sifting through extensive technical documentation. Nevertheless, the basic sleeve information we require includes the following:

1. Outside Diameter of the Pipeline: This measurement helps us determine the appropriate size of the shrink sleeve needed for the application at hand. Understanding the pipeline's diameter enables us to select the most suitable product from our range of options.

2. Operating Temperature: Covalence, the manufacturer of our shrink sleeves, produces a variety of products with different adhesive properties. The operating temperature of the pipeline plays a vital role in adhesive performance. Knowing this information allows us to recommend the most effective heat shrink sleeve for the specific temperature conditions.

3. Factory Applied Coating: It is important to consider the compatibility of adhesives with the existing factory applied line coating. Not all adhesives work harmoniously with every type of coating. For example, hot melt adhesives are generally not compatible with Polypropylene coatings. Identifying these potential issues in advance helps avoid costly discoveries during field operations, such as on a pipe lay barge where every day of operation carries significant financial implications.

4. Cutbacks: A cutback refers to the exposed steel surface between the factory applied coating and the end of the pipe. To determine the amount of bare steel present at a field joint, we multiply the cutback measurement by two. This calculation aids us in selecting an appropriately sized shrink sleeve for optimal coverage and protection (refer to resources [here] and [here] for further details).

Additionally, we require information regarding the specific application in which the heat shrink sleeve will be used. Factors such as whether it is a standard "drop in the ditch" pipeline, a road bore, a directional drill, a high-temperature line, an onshore or offshore project, or even a deep-water scenario, all influence our product recommendations. Understanding these details ensures that we provide tailored solutions for diverse operational environments, taking into account any unique challenges or requirements associated with each application.

We acknowledge that the amount of information requested may initially seem overwhelming or daunting. However, it is essential to recognize the significance of field joint coatings in every oil and gas pipeline joint. In fact, these coatings are a requirement rather than an option. Embracing this opportunity to enhance your sales numbers, increase profitability, and, perhaps most importantly, provide valuable service to your customers, who might otherwise choose an unsuitable product, is crucial. Furthermore, by partnering with Joint Specialists, you gain access to product experts who are just a phone call (936/321-3333) or an email (steve@jsicoatings.com) away. We are here to support you, leveraging our expertise to ensure your success.

Rest assured that with Joint Specialists, the seemingly complex task of selecting and quoting heat shrink sleeves becomes more manageable. We are committed to streamlining the process, offering efficient solutions, and delivering exceptional customer service. Contact us today to explore how we can assist you in making informed decisions and meeting your field joint coating needs

TPS Full Circle Sleeves

 TPS (tubular pipe sleeve) coatings are widely used in the pipeline industry for their excellent corrosion resistance and durability. TPS shrink sleeves are especially well-suited for harsh environments, such as those encountered in oil and gas pipelines. In this article, we will examine the reliability of TPS coatings based on the product thickness and properties of TPS coating.

Product Thickness:

The thickness of a pipeline coating is an essential factor in determining its effectiveness. The thickness of TPS coating can be measured in four different ways: backing as supplied, backing fully free recovered, adhesive as supplied, and wear cone (including coating) as supplied. Based on the data provided, the backing as supplied has a thickness of 1.85 mm (0.073 in.), while backing fully free recovered has a thickness of 2.3 mm (0.091 in.). The adhesive as supplied is 1.2 mm (0.047 in.), and the wear cone (including coating) as supplied is 3.05 mm (0.12 in.). This thickness provides a reliable barrier to prevent corrosion and other damages to the pipeline.

Product Properties:

The properties of a pipeline coating determine its resistance to various environmental factors. TPS coating exhibits excellent properties that make it a very reliable coating for pipelines. Let's examine each of these properties in detail.

Backing Bursting Strength: The backing bursting strength of TPS coating, as per DIN 30672, is 2350 N. This property indicates the strength of the TPS coating to withstand high-pressure situations.

Adhesive Softening Point: The adhesive softening point, as per ASTM E-28, is 94°C (201°F). This property indicates the temperature at which the adhesive will start to soften. This high softening point ensures that the TPS coating remains intact, even at high temperatures.

Lap Shear: The lap shear test as per EN 12068 @ 10mm (0.40")/min indicates the strength of the adhesive in the TPS coating. The typical value for lap shear is 0.55 N/mm² @ 50°C (122°F), indicating a strong bond between the adhesive and the pipe.

Sleeve Peel to Steel: The peel strength of TPS coating to steel, as per EN 12068 @ 10mm (0.40")/min, is 18 N/mm. This property indicates the strength of the TPS coating to remain attached to the pipe even in extreme environmental conditions.

Specific Coating Resistance: The specific coating resistance of TPS coating, as per DIN 30672, after 100 days of immersion, is 6 X 108 Ωm². This property indicates the resistance of the TPS coating to electrical current flow.

Impact Resistance: The impact resistance test as per EN 12068, Class C indicates the ability of DIRAX TPS coating to withstand impact forces. The TPS coating passes the test for a 15 J impact force.

Penetration Resistance: The penetration resistance test as per EN 12068, Class C50 indicates the ability of the TPS coating to resist penetration by sharp objects. DIRAX TPS coating has a penetration resistance of more than 0.6 mm at 50°C (122°F).

Cathodic Disbondment: The cathodic disbondment test as per EN 12068 for 30 days indicates the ability of DIRAX TPS coating to resist the disbondment of the coating from the pipe. The TPS coating maintains an 8 mm radius at 50°C (122°F), indicating its excellent bonding strength.

Based on the thickness and properties of TPS coating, we can conclude that it is a proven and excellent pipe coating for most standard pipeline applications.

Heat Shrink Sleeves: Essential Information for Accurate Quotes

 Heat Shrink Sleeves: Essential Information for Accurate Quotes

At Joint Specialists, we understand the practical realities of the buying process. Often, field joint coatings are among the last details to be addressed. In fact, a significant portion of our orders fall into the "emergency" or "hot tail gate rush" category. Nevertheless, even for these urgent orders, we require some fundamental information to provide suitable recommendations and pricing for shrink sleeve products.

While having access to the Field Joint Coating Specification makes our job easier (despite the need to sift through extensive technical data), there are basic details we need to know:

1. Outside Diameter of the Pipeline: This information determines the appropriate size of the shrink sleeve needed—whether it should be larger or smaller.

2. Operating Temperature during Service: Covalence manufactures various shrink sleeves with different types of adhesives. Knowing the operating temperature is crucial because it significantly affects adhesive performance.

3. Factory Applied Coating: Not all adhesives are compatible with every factory applied line coating. For example, hot melt adhesives are generally not compatible with Polypropylene. We aim to avoid discovering such incompatibilities in the field, especially during pipe laying operations that incur substantial daily costs.

4. Cutbacks: A cutback refers to the amount of bare steel between the factory applied coating and the pipe's end. To determine the extent of bare steel at a field joint, we double the cutback measurement. This helps us ascertain the necessary width of the shrink sleeve (refer to here and here for more details).

Lastly, we need to know the application specifics, such as whether it's a standard "drop in the ditch" pipeline, road bore, directional drill, high-temperature line, onshore, above ground, offshore, deep water, S-Lay, or J-Lay. The answers to these questions can impact the recommendations we provide.

We understand that gathering this information may appear overwhelming at first glance. However, it's not as challenging as it seems. Every joint of oil and gas pipeline requires some form of field joint coating. This presents an opportunity to increase your sales and profits modestly while offering a valuable service to customers who might otherwise choose the wrong product. Furthermore, by partnering with Joint Specialists, you have access to product experts who are just a phone call (936/321-3333) or email (steve@jsicoatings.com) away.

WPCT Shrink Sleeves

 

WPCT - The Original Wrap Around Heat Shrinkable Sleeve

WPCT heat shrinkable sleeves are a type of protective covering used in various industries, particularly for pipeline applications. WPCT stands for "Wraparound Pipe Coating with Thermal indicator," and these sleeves are designed to provide excellent protection against corrosion, moisture ingress, and mechanical damage to pipelines and other similar structures.

The heat shrinkable sleeves are made from a specialized blend of polymer materials that have the property to shrink in size when heat is applied. They are typically composed of a heat shrinkable backing material and an adhesive layer. The backing material is a cross-linked polyethylene or polyolefin, which provides strength and durability to the sleeve.

The adhesive layer is designed to bond the sleeve to the surface of the pipeline. It is formulated to offer excellent adhesion to steel substrates, ensuring a tight and secure fit. The adhesive layer also acts as a barrier, preventing moisture and corrosive substances from reaching the pipeline's surface.

The outer layer of the WPCT shrink sleeve is the heat-shrinkable component. When heat is applied, typically using a propane torch or a specialized heat gun, the sleeve shrinks in size, tightly conforming to the shape of the pipeline. This shrinkage creates a robust, seamless, and waterproof barrier that protects the pipeline from corrosion, abrasion, and environmental factors.

WPCT heat shrinkable sleeves are often used in applications where pipelines are exposed to harsh environments, such as underground installations, marine environments, or chemical processing plants. They provide long-term protection, extending the lifespan of the pipeline and reducing maintenance costs.

In summary, WPCT heat shrinkable sleeves are protective coverings that are heat-applied to pipelines. They offer corrosion resistance, waterproofing, and mechanical protection, making them an effective solution for preserving the integrity of pipelines in challenging conditions.

Raychem / Covalence Heat Shrink Sleeve Advantages

Advantages of Covalence Shrink Sleeves (formerly Raychem)

Demanding Applications

In order to protect metal pipe structures in contact with an electrolyte (soil, water) coatings need to have a high electrical resistance and low permeability to hydrogen and oxygen. 
The coating must also be physically strong and chemically stable.
Additionally, the requirements of particular applications, like high operating temperatures necessitate specific tailoring of all pipeline coatings, including heat shrinkable sleeves.

Optimal Solutions

To provide the optimal solution for each application, Raychem offers a range of products based on an irradiated crosslinked polyethylene carrier, combined with a hot melt or mastic coating applied in the factory to that heat shrink backing.
The main purpose of the crosslinked carrier (the actual heat shrink sleeve), called the backing, is to provide a strong barrier against electrical current, permeation and mechanical forces.
The adhesive assures long term bonding of the backing to the pipe and provides added electrical resistance (which is a good thing in spite of the propaganda you are regularly exposed to) and mechanical strength.
Thickness of the backing and adhesive depend on the application requirements. 

To sum that up:  Strengths of the heat shrink sleeve include (but are not limited to):
- Chemical Resistance of heat shrink backing and the selected adhesive
- Flow and fill of the hot melt adhesive or mastic sealant
- Mechanical Strength of the heat shrinkable backing (which can potentially be multiple layers and include fiber reinforcement)
- Electrical Resistance of both the backing and the adhesive.  A coating with no electrical resistance means your pipeline is going to rely on your CP system almost solely for corrosion prevention.  Why not just leave the field joints as bare steel if that is your goal?

Three Layer Coatings

For the increasingly common (in Europe, South America and Asia) three layer factory applied pipeline coatings, Raychem / Covalence has developed a three layer field applied field joint coating.  To provide a homogeneously coated pipe surface in the girth weld area, a layer of two component epoxy is first applied to the surface of the pipe.  A specially designed shrink sleeve is then applied over the wet epoxy. 
The three layer heat shrinkable coating system performs extremely well in resisting cathodic disbondment.  It also offers high shear resistance against soil load and consequently ensures long service life. 

High Reliability, High Performance

Raychem (now called Covalence) has more than 40 years of experience in the development and manufacturer of heat shrinkable products.  Continuous improvement ensures state of the art performance.  Approval by testing agencies around the world guarantees suitability for individual applications and field conditions. 
- Two layer and three layer constructions complement wide range of pipe coatings
- Top quality hotmelt, copolymer coated sleeves resist elevated pipe operating temperatures and soil stresses on all pipe diameters.
- Mastic coated shrink sleeves balance performance, economy and easy of installation.
- Three layer sleeves with epoxy primer and hotmelt copolymer have excellent resistance to both cathodic disbondment and hot water immersion, even at maximum rated operating temperatures.
- Fiberglass reinforced heat shrink sleeves withstand the high stresses of directional drilling
- Self-healing adhesive slow automatically repairs minor mechanical damage

Low Installation Costs

- No primer required for two layer heat shrink sleeve systemes - install directly on cleaned and preheated pipe surface
- No waiting for primers to cure.  The shrink sleeve is installed directly over the wet epoxy
- Simple tools such as a hand brush, power brush or blast cleaning and propane torches are used for installation of the heat shrink sleeve
- All products available as Uni sleeve construction.  Uni sleeve means the closure strips are attached to the shrink sleeve here in our shop allowing for quicker installation in the field and dramatically fewer field issues.
- Easy to understand installation instructions are shipped with every product; in every box of shrink sleeves.  Clear product labelling on the outside of the boxes allows rapid on site installation.

Premium Service with Joint Specialists

To place an order or inquire about products, contact us at 936 /321-333 or email to steve@jsicoatings.com  We pride ourselves on offering the best customer service in the industry with very quick turnarounds on information, pricing and delivery.

Cost Analysis Shrink Sleeves vs Epoxies

Epoxies versus Heat Shrink Sleeves Cost Analysis

     This is a fairly common question that comes up from contractors:  which is cheaper epoxies or shrink sleeves?  As with just about every question that comes up, the question really deserves a close, in depth analysis.  The truth is, I distribute two part epoxies (Powercrete and Denso) and I distribute heat shrinkable sleeves (Covalence formerly called Raychem).  I am very familiar with both products including their installation procedures and their material costs.  For the sake of this comparison I'm looking at our standard wrap around shrink sleeve designed for ambient temperature pipelines.  I'm also looking at a one of the most commonly used, hand applied two part epoxies on the marketplace. 

    Quick disclaimer: each product technology has its own unique set of technical advantages and strengths -- and each has its own unique set of challenges.  This article is dealing purely with the cost aspect.  

     In both cases I'm going to look at something simple like a 12" pipe.  I'm also going to assume an FBE coated line where the standard cutbacks are around 2-3 inches per side. 

     So the basics first, Material Cost:

List price of 2 part epoxy in a 25-30 mil thickness:  ~$11.80 per field joint

List price of a standard WPCT shrink sleeve in a 100 mil thickness:  ~$11.60 per field joint

     In addition, that epoxy cost is based on getting several field joints out of a single two part epoxy kit.  If there were factors that led to the inability of the installer to be efficient with the epoxy, that cost per field joint could double or even triple.  What are the factor that could cause an inefficient use of the epoxy (and thus a dramatic increase in material cost)?

• a right of way that doesn't allow for multiple field joints to be coated within a window of a few minutes
• hot temperatures that cause reduced pot life of the mixed epoxy
• crews not working quickly enough to use epoxy prior to cure
• ambient conditions requiring multiple coats of epoxy to meet specification

      Considering only material costs for an ambient temperature, standard drop in a ditch application pipeline- the shrink sleeves offer some monetary savings.  What does the picture look like when we begin to consider labor costs?  I'm afraid for these comparisons, I'm flying blind a bit.  I do not know what labor costs or equipment rental costs are; so rather than make things up, I will simply outline things so that you can use your own expertise to determine for yourself what effect these factors will have on overall coating cost. 

Surface Preparation:
WPCT can be installed on a wire brushed pipe surface in order to create a surface that is free of oils, greases and foreign material.

Epoxies must be installed on a grit blasted surface with the proper anchor pattern in the steel. 

Wire brush vs grit blasting - I have to believe the cost advantage here goes to shrink sleeves

Installation Time: 
This one can get a bit tricky as there are so many factors.  Looking at preheating the steel and wrapping and shrinking the sleeve properly, I'd estimate an installation on 12" pipe at ~4 minutes.

Installation time for the epoxy?  I honestly can't say as it will be heavily dependent on installer skill, ambient temperature, cure times, thickness applied per coat and how well that specific epoxy is hanging on the pipe. 

Install time - Again, I have to believe the cost advantage goes to shrink sleeves here.

Inspector Issues:
With shrink sleeves there are certainly things that can be (and should be) on an inspectors radar.  The inspector needs to be certain the pipe is being properly preheated prior to wrapping the sleeve.  The inspector needs to give a visual inspection to make certain there are no cold spots and that the sleeve shows adhesive flow on all edges.  If there are cold spots or if there is a lack of adhesive flow, the crew will need to reheat that shrink sleeve and correct those issues which can take 2-3 minutes.

With epoxies, the inspector needs to make sure that the coating thickness is correct and meeting the specification.  The inspector needs to be certain that any icicles are within the end users tolerance levels.  The inspector needs to be certain there is no cracking.  In cases where corrective action is required, the crews will need to remix more material, reapply it properly and if necessary add more than one coat to bring that field joint up to spec. 

Inspector issues:  Red flags on a shrink sleeve require a few minutes of time.  Red flags on epoxy are generally going to require more material (cost) and time.  The cost advantage here must go to shrink sleeves.

Repairs: 
Shrink sleeves by their very nature are very, very tough.  Beyond that, installers require no special equipment or training in order to properly apply them.  Every box includes a detailed installation instruction and all of the most important aspects of the coating (thickness, seal ability, etc) are outside of the installers control.  Shrink sleeves are very difficult to accidentally damage, and as a result, repairs are incredibly rare.

Epoxies can require repairs more often.  Jeeping the field joint can cause previously unseen holidays to appear.  Bugs can fly into the epoxy prior to cure.  Brushing up against the field joint prior to cure can cause damage.  Grass or pine needles or dirt or dust can be blown into the coating by the wind.  Any of those can require repairs.  Every repair requires more material be mixed which results in a higher material cost and a higher labor cost. 

Repairs:  Advantage has to go to shrink sleeves on this one. 

     So there you have it.  By my estimation, looking at a standard 12" pipeline, shrink sleeves are going to be less expensive in every single aspect; including material cost, labor cost, repair cost and surface prep cost.  I'm trying to figure out:  why does it seem like a 'commonly accepted' fact that two part epoxies are a more cost effective option than shrink sleeves?  I do not know (though I would say that when spray applying epoxies; this picture might look a bit different, but that is outside of my own personal expertise so I can't honestly comment on it). 

     Keep in mind, I understand completely that there are some specifications out there that allow ONLY heat shrinkable sleeves.  I also know there are specifications out there that allow ONLY two part epoxies.  My focus here is simply to say: if you are working on a project that contains an allowance for either technology; it is absolutely, positively worth your time to consider how each product technology (shrink sleeves and epoxies) will impact your profits on the line.  Looking at all of these considerations, one option could make for a job that is dramatically more profitable than the other. 

Berry Plastics - Covalence Shrink Sleeves

Berry Plastics Covalence Heat Shrinkable Sleeves

     Above, you see the logos for both Berry Plastics and Covalence heat shrinkable technology.  Berry Plastics is the owner of many, many, many companies....one of which is Seal for Life.  Seal for Life owns and operates several pipeline coating technologies, one of which is Covalence heat shrinkable sleeves which were formerly known as Raychem heat shrinkable sleeves or Tyco Adhesives or Tyco Electronics or Tyco CPG (Tyco Corrosion Prevention Group).  Things sure do get awfully confusing at times in 2015 corporate America, don't they??

     Though the name has changed many times over the last decade (and I'm afraid there is the distinct possibility that the name changes again several times in the coming decade), there are a few facts that are important to remember.  In this last decade, the products haven't changed a bit.  The manufacturing plant has not changed a bit.  The stringent quality requirements haven't changed a bit.  The excessively strong product performance hasn't changed a bit.  The only change has been the labels on the boxes and the printing on the sleeves themselves. 

     So whether you are looking for the premiere product for coating road bores and directional drilling applications:  DIRAX.  Or whether you are looking for our standard WPCT shrink sleeves (or our WPC100M or our WPC120 or our HTLP sleeves), you've come to the right place. 

     In addition, if you are looking for shrink sleeves that meet the AWWA C216 standard, we have those as well:

     So, don't let the "Berry Plastics" name scare you.  Sure, they are the industry leader is mass produced plastic materials selling everything from plastic bags to plastic containers....but they are also the industry leader in pipeline coating prevention products; with multiple product technologies in their bag including two part epoxies (Powercrete), viscoelastic (Stopaq), shrink sleeves (Covalence), tapes (Polyken) and linear anodes (Anodeflex). 

Shrink Sleeve Adhesive Thickness Over Weld Bead

Shrink Sleeve Mastic Thickness and the Girth Weld

      Though not a question that comes up too often these days, during the time when heat shrink sleeves were exploding in the pipeline coatings market (and other markets as well) there was often a contentious debate about mastic adhesive thickness....and what the minimums should be in order to assure proper mastic flow and filling around the weld bead...and at the step down areas from the factory applied coating to the bare steel.  Below is one such analysis completed in 1979. 

     Scope:  This report presents data and observation on the ability of various corrosion preventive products used in joint protection to fill and seal over and around a weld bead.  The results of this analysis will also cross over (based on factory applied pipeline coating thickness) to shed light on the required thickness of adhesive on different pipeline coatings to properly fill at the step down area from factory applied coating to bare steel.

     Test Procedure:  Samples were applied to a 4.5" diameter steel pipe with a circumferential weld bead.  Test samples were applied in accordance with the manufacturer's installation instructions.  After 24 hours, pipeline coating test specimens were examined for voids or leak paths around the are of the weld bead.  During this test, weld bead dimensions were .100" high and .350" wide. 

     Test Samples:
#1: Heat Shrink Tubular Sleeve with total adhesive thickness of 25 mils
#2: Heat Shrinkable Tube Sleeve with total adhesive thickness of 30 mils (<- Covalence)
#3: Heat Shrink Tube Sleeve with total adhesive thickness of 10 mils
#4: Heat Shrinkable Wrap Around sleeve with total adhesive thickness of 70 mils (<- Covalence)
#5 Heat Shrink Wrap Sleeve with total adhesive thickness of 25 mils
#6 Cold Applied Tape with total adhesive thickness of 30 mils
#7 Cold Applied Tape with total adhesive thickness of 40 mils

     Observations After Testing
#1: With a 25 mil supplied adhesive thickness -this shrink sleeve lacked enough flow and volume to fill areas along weld beads leaving a continuous leak path under the shrink sleeve.

#2: (30 mil) The sealant thickness and flow properties were sufficient to obtain complete filling of the weld bead area.

#3: (10 mil) The mastic showed good flow properties but lacked enough sealant thickness to adequately fill around the weld bead area. 

#4: (70 mil) There was sufficient amount of sealant present which flowed well upon heating to give a void-free seal in the weld bead area. 

#5: (25 mil) Insufficient sealant thickness plus low flow properties contributed to a void line along the weld bead. 

#6 & #7: (30 mil and 40 mil) Both of these samples exhibited continuous void lines along the sides of the weld bead.  It has been found that during the application of cold applied tapes, there is a bridging effect which traps air to cause voids along the weld bead.  Most sealants have limited flow when applied at room temperature and do not fill well around the weld bead.

     Conclusions:  The table above lists the various samples tested and gives a comparison of the sealant thicknesses.  Sample 1, 2 and 3 are tubular heat shrinkable sleeves (supplied in the shape of a tube) which, due to their recovery ratio, will have variable sealant thicknesses depending on the degree of recovery.
     Results indicated that an adhesive thickness of 30 to 35 mils is needed to adequately fill around the weld bead on the test fixture. 
     As indicated in several of the observations, a second factor which is equally important is the ability of the sealant to flow during installation.  Samples 1 and 5 both showed low flow characteristics when heated; this contributed to the lack of filling.  Samples 6 and 7 also showed very low flow because of being cold applied.  As noted in the observations, this is a common and known shortcoming of cold applied tapes.
     In general, a product must have a balance of adequate coating thickness (approximately 30 mils or above) and good flow characteristics during installation to deliver a void free corrosion protection coating to the weld bead. 

 

Weld Joint Coating on Pipelines Coated with FBE

Technical Comparison between FBE Powder and Heat Shrink Sleeves

1 - Introduction

     Both joint coatings are used in the field and both have their advantages and disadvantages with regard to materials and application methods.

 

1.1 - Weld joint coating with epoxy powder

     The application process is the following:

     a) clean the exposed steel by sand or grit blasting to a degree of cleanliness of SA3 (or better)

     b) provide, by the same operation and the selection of the abrasive, a surface roughness of 80 to 160 microns (as required by the epoxy powder supplier) in order to create an adequate anchor pattern for the epoxy layer to adhere to the steel surface. 

     c) eliminate all sharp edges with a file or mechanic tool (all thin film coatings need this special care as part of the surface preparation).

     d) clean both edges of the adjacent line coating with a  solvent, to remove all traces of dirt, debris, oil, grease or other contamination.

     e) preheat the joint, with due consideration to the ambient temperature and the thermal inertia of the steel mass, up to 220C, to obtain a perfect fusion of the epoxy powder particles amongst themselves and with the steel surface. 

     f) apply the epoxy powder with an electrostatic spray gun (or flocker)

     g) allow to cure

     h) check the result

     i) paint holidays in the joint coating with liquid epoxy or FBE repair sticks

 

1.2 - Heat shrinkable sleeves

     The application is the following:

     a) clean the exposed steel by wire brushing to a cleanliness of ST3 or alternatively SA2 or SA 2 1/2 (some products require more surface preparation than others).
     b) clean superficially the two edges of the line coating.
     c) preheate the joint area to 80-160C (depending on the manufacturer's recommendation)
     d) if applicable, precoat the bare metal and adjacent FBE with epoxy primer
     e) wrap sleeve and secure closure
     f) shrink the sleeve on the pipe
     g) inspect

2 - Comparison
     Both processes give excellent results, provided they are applied in accordance with all applicable instructions.  However, all site operations made to date with the epoxy powder spraying method have shown a major drawback:  the process is complicated and not really appropriate for some field conditions. 

2.1 - Methods
     Fusion bonded epoxy powder needs to be applied under specific conditions and using specialized equipment that can only be properly controlled in a plant and at a very complex technical level.  It is not at all easy to ensure this same performance level under field conditions.

2.2 - Equipment

2.2.1 - The equipment required for the fusion bonded epoxy powder joint coating is comprised of the following:
     - a refrigerated storage container (the shelf and storage life of the epoxy powder decreases rapidly at temperatures exceeding 20C)
     - a mobile grit / sand blasting unit, that can achieve the required anchor pattern.
     - a solvent storage outfit with fire extinguishers
     - a screening, recycling and conditioning installation (fluidized bed) plus a primary electric power source.
     - an induction pipe preheating system, including a special generator set (single phase, 800 or more cycles, special cables and an induction coil per pipe size.
     - powder spray equipment with electrostatic spray gun
     - control equipment for constant monitoring of temperature and gelling
Most of the above equipment utilizes electronic components that suffer from voltage variations, temperature excursions and vibration (coming from the generator sets on the same frame). 

2.2.2 - The equipment required for heat shrink sleeve installation is:
     - electric or pneumatic wire brushes, or a simple sandblasting outfit
     - propane torches with propane bottles, or a simple induction heating system

2.3 - Skill of operators
     The complex application procedure of fusion bonded epoxy powder requires highly qualified technicians for both, powder application and equipment maintenance.  The application of heat shrink sleeves is a matter of a few hours of training. 

2.4 - Necessary manpower
     All the various activities involved with the storage / feeding / reconditioning and application of the epoxy powder obviously require much more manpower than the simple shrinking of sleeves.  Even when labor is inexpensive, this may become an important issue.  Very often, sites are in remote locations and only limited space is available in the living quarters. 

2.5 - Ease of creating supplementary crews
     If, during the construction period, more application crews become necessary, it is very easy to put together another crew of skilled heat shrink installers, as there is virtually no supplementary equipment needed.  On the other hand, every supplementary crew for epoxy powder needs new highly skilled specialists and a complete set of the equipment described in 2.2

2.6 - Life time of raw materials
     Epoxy powder has a limited life time, depending very much on storage and handling conditions.  A heat shrink sleeve can be kept in store for an unlimited period of time and at temperatures up to 55C

2.7 - Preheating temperatures
     The preheating temperatures for epoxy powder are in the range of 220C.  To obtain a uniform thickness, a uniform preheating temperature is an absolute must.
     Preheating temperatures for heat shrink sleeves are in the range of 80-160C, depending on the adhesives used.  In case of a liquid epoxy first layer, the preheating needs only to be at 60C for all adhesives.  Preheat temperatures up to 100C can be easily achieved with propane torches under all field conditions.

2.8 - Tie-ins
     For the epoxy powder, every tie-in crew also needs a complete set of equipment.  The equipment for tie-ins needs to be even more mobile than the standard joint-protection set. 

2.9 - Back-up equipment
     For the epoxy powder process at least one complete spare set of equipment needs to be kept on hand to avoid risking the complete shut down of the job.