A Trip Back to 1975: Raychem LTPS in Corpus Christi, Texas

This week, we’re heading back in time—December 1975, to be exact—to beautiful Corpus Christi, Texas. The project? A pipeline installation featuring one of Raychem’s now-retired products: LTPS.

Based on old Raychem nomenclature (which, let’s be honest, was usually more practical than poetic), LTPS likely stood for “Large Tubular Pipe Sleeve.” I’ve said it before and I’ll say it again—Raychem was incredibly creative when it came to products, backings, and sealants. When it came to naming them? Not so much!

This particular job involved 18-inch and 20-inch pipe, which meant these LTPS sleeves had to be installed before the pipe joints were welded. The process would have looked something like this:

1. Sleeve Placement (Pre-Weld)
   The shrink sleeve was slipped onto the pipe before welding took place.

2. Weld Completion
   Once the joint was welded, the crew prepared the weld area.

3. Surface Prep & Preheat
   The weld zone was cleaned thoroughly and preheated to at least 140°F—critical for proper adhesion and shrink performance.

4. Positioning the Sleeve
   The LTPS sleeve was then slid into place over the weld area.

5. Release Liner Removal
   The liner was removed to expose the adhesive.

6. Shrink It!
   Using a propane torch, the installer shrank the sleeve tightly over the joint, creating a protective, sealed coating.

LTPS has been a dead product for as long as I’ve been around. However, its smaller sibling—TPS—is still very much alive and well. Today, TPS sleeves are regularly sold for 2", 2.5", 3.5", 4.5", 6" and 8".

While product lines evolve, it’s always fascinating to see the roots of today’s solutions in these legacy installations.

What really makes this project memorable are the photos. In one shot, the installer is casually smoking a cigarette through the entire application process—while operating a propane torch.

Different times, indeed.

It’s wild to think that 1975 was 51 years ago. The industry has changed. Safety standards have changed. Product technology has changed. But there’s something timeless about looking back at these projects and appreciating the craftsmanship and ingenuity that laid the groundwork for where we are today.

Here’s to the legacy of LTPS—and to the crews who made it work in Corpus Christi, December 1975.

 

Tubular Shrink Sleeves Aren’t Going Away: A Look at Covalence TPS

This may surprise some folks in the pipeline world, but simple tubular shrink sleeves are still very much in use—especially on smaller diameter pipe. In fact, for many applications, they remain a practical, reliable, and cost-effective solution.

One standout example is Covalence TPS (Tubular Pipe Sleeve), formerly a Raychem product, which continues to see strong demand in the field.

A Proven Solution for Small Diameter Pipe

TPS is available for pipe sizes ranging from 2” through 8”, making it a go-to option for smaller diameter pipelines where simplicity and speed matter. Despite the evolution of field joint coatings over the years, TPS has held its ground—and for good reason.

Straightforward Installation, Strong Performance

Installation is refreshingly simple:

• The TPS sleeve is slipped onto the pipe prior to welding

• Once the weld is complete, the sleeve is slid back into position

• The release liner is removed

• The sleeve is then shrunk in place using a propane torch

No blasting required—wire-brushed pipe surfaces are sufficient, thanks to the highly aggressive mastic sealant that delivers a reliable seal and long-term protection.

If you’ve ever wondered whether TPS is still actively used, consider this:
the pallets stacked behind this sleeve are all TPS. We keep large volumes in stock, with each sleeve providing 18 inches of pipe coverage prior to shrinking. That kind of inventory doesn’t exist unless the product is still solving real-world problems.

TPS may not be the right answer for every project—but when conditions, pipe size, and installation requirements line up, it can be an excellent fit.

If you think Covalence TPS tubular shrink sleeves might work for your application, we’d love to talk it through with you. Sometimes, the simplest solutions are still the best ones.

 

 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.

1973 Job Report

 

A Blast From the Past: Raychem Shrink Sleeves in 1973 — and How Covalence Continues to Lead Today

Every once in a while, a photo pops up that reminds us just how far the pipeline industry has come. This morning delivered one of those gems:

July 1973 — Tampa, Florida — Raychem Shrink Sleeves being installed on 45s, 90s, and straight-line field joints.

Back then, Raychem was the name everyone knew for heat-shrinkable pipeline coatings. Over the decades, the brand evolved into Covalence, now part of Seal for Life Industries, owned by Henkel. But that original innovation DNA? Still very much alive.

And the picture from that Florida project?
A completely different world.

No shirts.
No gloves.
No FR clothing.
No PPE.
Just a crew, a torch, and a box of Raychem sleeves — and somehow, no problem!

Despite the “old-school” approach, those early shrink sleeves performed incredibly well. The technology was solid, the materials were ahead of their time, and Raychem quickly became the global standard for field joint coatings.

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From Raychem to Covalence: The Same Heritage, But a Much Bigger Toolbox

Fast-forward 52 years, and Covalence remains one of the industry’s most trusted names — not because the products stayed the same, but because they kept evolving.

Today, Covalence offers field-proven solutions for:

• Straight pipe

• Hot bends

• Cold bends

• Fittings

• Tie-ins

• Directional drilling

• Road bores

• Specialty applications

If there’s a pipeline, chances are Covalence has a coating for it.

And while those 1973 TPS slip-on sleeves got the job done, our approach to bends today is even better.

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Why Today We Recommend Covalence Flexclad for Bends

If you were coating 45s and 90s today, you wouldn’t be reaching for a slip-on sleeve — you’d be reaching for Covalence Flexclad, the industry’s premier heat-shrinkable wrap-around tape for bends.

Why Flexclad?

• Form-fits perfectly around any curvature

• No wrinkling or bridging

• Handles movement and strain exceptionally well

• Eliminates the difficulty of sliding a sleeve over a bend

• Delivers long-term corrosion and mechanical protection

• Proven Covalence adhesive technology underneath

Flexclad is simply the modern, reliable answer for bend coating — engineered from decades of experience that began with those early Raychem installations.

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Pipeline Coatings Have Evolved — And So Have We

As fun as it is to look back at a 1973 jobsite where safety culture meant “try not to burn yourself”, it’s even more exciting to see how far the industry has come.

Better materials.
Better chemistry.
Better installation techniques.
Better safety.
Better results.

But the through-line remains the same:

Covalence continues to deliver coating systems for nearly every pipeline application — from the simplest field joint to the most challenging bend.

The tools have changed.
The safety standards have changed.
The industry has changed.

But the legacy of innovation — from Raychem to Covalence — is still shaping the pipeline world today.

Covalence Shrink Sleeves

 Covalence Heat Shrink Sleeves for Field Joints

In the oil and gas industry, protecting pipelines from corrosion is critical to long-term performance and safety. One of the most vulnerable points on a pipeline is the field joint—the exposed area created when two factory-coated pipe segments are welded together during construction. This uncoated zone must be properly protected in the field using a coating that restores corrosion resistance, bonds reliably to the adjacent factory-applied coatings, and withstands environmental and mechanical stresses. One of the most trusted solutions for this purpose is Covalence™ heat shrink sleeves, formerly known as Raychem.

Covalence heat shrink sleeves have been used worldwide for decades to protect field joints on pipelines coated with Fusion Bonded Epoxy (FBE), 3-Layer Polyethylene (3LPE), 3-Layer Polypropylene (3LPP), and other common coating systems. These sleeves consist of a cross-linked polyolefin backing combined with a high-performance adhesive layer. When heated, the sleeve shrinks tightly around the joint, and the adhesive melts, forming a durable, moisture-resistant seal that prevents corrosion.

The benefits of Covalence sleeves are numerous. They offer excellent adhesion to bare steel as well as to factory coatings, ensuring a continuous protective barrier across the field joint. Installation is efficient and consistent; technicians wrap the sleeve around the pipe, apply heat using a torch or induction equipment, and the sleeve conforms tightly to the surface. This quick and repeatable process minimizes downtime on the job site and supports project efficiency.

Covalence sleeves are also designed to withstand the tough conditions pipelines often face. Once installed, they resist impact, abrasion, and soil stress, making them suitable for use in demanding scenarios such as directional drilling, rocky terrain, or road crossings. The company offers a range of sleeve products to meet various pipeline conditions and requirements. For example, DIRAX sleeves are specifically designed for horizontal directional drilling, WPCT sleeves are used for moderate-temperature buried pipelines, WPC100M is suited for standard field joint applications, and TPS sleeves are sold as tubular or slip on shrink sleeves.

Another important advantage of Covalence products is their compatibility with global industry standards. These sleeves are designed to meet or exceed specifications from organizations such as ISO, CSA, and AWWA, and are approved by many of the world’s leading oil and gas pipeline operators. Their performance has been validated in countless projects across a wide range of environmental conditions—from arctic climates in Alaska and Russia to high-temperature installations in the Middle East.

The application process for Covalence heat shrink sleeves involves several key steps. First, the weld area must be cleaned to the specified standard, usually near-white metal blast. Then, the surface is preheated to activate the adhesive and ensure proper bonding. The sleeve is positioned around the joint with overlap onto the adjacent coating, and heat is applied to shrink the sleeve and flow the adhesive. After installation, the sleeve conforms tightly to the pipe surface and forms a reliable seal. A visual inspection and optional holiday testing confirm the success of the installation.

In summary, Covalence heat shrink sleeves offer a field-proven, reliable, and efficient solution for protecting field joints on oil and gas pipelines. Their strong adhesion, mechanical resilience, ease of installation, and global track record make them a preferred choice among pipeline engineers and contractors. As oil and gas infrastructure continues to expand and age, using proven technologies like Covalence ensures pipelines remain protected and operational for decades to come.

 Covalence Shrink Sleeves (formerly Raychem)

Seal For Life’s Covalence brand offers a comprehensive range of heat shrinkable products designed for corrosion prevention, mechanical protection, and sealing of pipelines, including field joints and pre-insulated pipe systems. Below is an overview of their main product offerings and applications:

• Covalence provides both 2-layer and 3-layer heat-shrinkable sleeves.

• These sleeves feature irradiation cross-linked polyethylene or polypropylene backings, combined with adhesive layers (either visco-elastic mastic or co-polymer hot melt) tailored for different pipeline operating temperatures and environments.

• The 3-layer systems often include an epoxy primer for enhanced adhesion and are compatible with modern multi-layer mainline coatings, creating a monolithic protection system.

• : A two-layer field-joint coating system designed for corrosion protection of pipelines operating at ambient temperatures. It is among the most widely used solutions for girth weld protection.

• : High-performance, three-layer sleeves with epoxy primer, designed for pipelines with higher operating temperatures and demanding environments. These sleeves offer excellent resistance to cathodic disbondment, hot water immersion, and soil/thermal movement stresses - HTLP60 & HTLP80

• : Specifically engineered for directional drilling and applications requiring extra mechanical strength - DIRAX & CCS Material used to make Caseals and Flangeseals.

• : Designed to provide durable sealing solutions for pre-insulated pipe joints, protecting against moisture ingress and maintaining thermal integrity.

• : Includes joint casings, foaming hole closures, primary joint foam seals, end caps, and sealants to support a wide range of pipeline configurations and field conditions.

• High electrical resistance and low permeability for optimal corrosion prevention.

• Designed for easy installation with minimal tools and surface preparation.

• Approved by major testing agencies worldwide, ensuring suitability for diverse field conditions and compliance with global standards such as ISO, EN, AWWA, NACE, and GOST.

• Proven performance record in major pipeline projects globally, including oil, gas, and water transmission lines.

Product Type	Layers	Key Application	Notable Features
WPCT	2	Field joint corrosion protection	Ambient temperature pipelines
HTLP Series	3	High-temp, high-stress environments	Epoxy primer, soil/thermal resistance
Fiberglass-Reinforced Sleeves	2–3	Directional drilling, mechanical stress	Extra strength, abrasion resistance
Pre-Insulated Pipe Sleeves	2–3	Pre-insulated pipe joints	Moisture and thermal protection

Covalence’s heat shrinkable products are trusted globally for their reliability, versatility, and ease of installation, making them a leading choice for pipeline protection and sealing needs.