Waterwrap: A 50-Year Journey That Started with an Opportunity

 

It was October of 1975 when a team of Raychem pipeliners headed south to Grand Gulf, Mississippi with a simple goal: solve a real problem in the field.

At the time, the large-diameter pipe market was struggling with a familiar challenge—how to reliably coat field joints in a way that was consistent, repeatable, and practical for crews working under tough conditions. And in those days, when Raychem identified a need, the company didn’t hesitate. They saw opportunity.

In the mid-1970s, Raychem was best known for manufacturing tubular heat-shrink sleeves for oil and gas pipelines. One of the flagship products was the TSS (Tubular Shrink Sleeve). It worked well—but only when pipe sizes and logistics allowed for a sleeve that could slide over the pipe.

Large-diameter pipe created a new challenge. You couldn’t easily slip a tubular sleeve over it in the field. So Raychem’s engineers did what they did best: they invented something new.

The result was a wrap-around heat-shrink sleeve prototype designed specifically for large pipe. And what did they call it?

LTSS — Large Tubular Shrink Sleeve
(…even though it wasn’t actually supplied as a tube).

Raychem was exceptional at innovation and rapid R&D. Naming products? Maybe not their strongest suit—but the technology was what mattered.

Armed with LTSS sleeves and a team of field technicians, Raychem went to work evaluating the new design under real-world conditions. What’s fascinating—at least to those of us who live and breathe pipeline coatings—is that this LTSS prototype was the first generation of what we now know as Waterwrap.

Over the decades, that original concept evolved dramatically:

• Improved formulations

• New backing materials

• Multiple thickness options

• Enhanced performance for demanding environments

Each improvement built on the last, refining the product into something truly special.

Waterwrap Today

Fast-forward nearly 50 years, and Waterwrap stands as the premier field joint coating for water pipelines. It’s trusted around the world for its reliability, ease of installation, and long-term performance.

Even more impressive? Waterwrap has proven itself capable in weld-after-backfill applications—one of the most demanding scenarios a field joint coating can face.

Every proven product has a beginning. For Waterwrap, that beginning was a forward-thinking team in 1975, a job site in Mississippi, and a willingness to rethink how field joints could be protected.

So here’s to 1975 Raychem—seeing a problem, seizing an opportunity, and laying the groundwork for a product that’s still protecting pipelines half a century later.

Well done.

Waterwrap: Weld after backfill sleeve

 Coating CHALLENGE: Covalence Waterwrap (Weld After Backfill)

Today we’re taking a look at Covalence Waterwrap – Weld After Backfill (WAB), a product designed for one of the most demanding coating applications you’ll ever encounter.

Let’s start with the baseline challenge.

You’re dealing with massive, heavy pipe. It’s already in the ground. Preheating a pipe with that much thermal mass is no small task. Installation crews have to be absolutely disciplined—every square inch of the sleeve must be properly heated to ensure a reliable bond. None of this is easy on a good day.

Now add this twist:
the pipe is going to be welded after the sleeve has been installed.

Yeah… kind of nuts.

Don’t let the photo above fool you (I borrowed it from tomorrow’s history post, which goes all the way back to 1975). What’s interesting about that image isn’t just what you see—it’s what it represents.

The product shown, LTSS, was literally Raychem’s first serious attempt at developing a solution for large-diameter water lines. It was an important starting point, but very much a first pass.

Fast forward to today.

Waterwrap WAB is the result of dozens of generations of product evolution, refined over decades. Each iteration has been driven by real-world field experience—improving long-term performance on the pipe while simultaneously making life easier for installation crews. Better materials. Better installation tolerance. Better outcomes where failure simply isn’t an option.

That kind of evolution matters when you’re coating buried pipe, welding after backfill, and asking a system to perform flawlessly for decades underground.

If you’re in the water pipeline construction world and dealing with these kinds of challenges, we’d love to talk. There’s a lot of hard-earned history—and a lot of practical knowledge—behind today’s Waterwrap systems, and we’re always happy to share it.

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.

Weld After Backfill Shrink Sleeve Installation Guideline

Covalence Waterwrap -Weld After Backfill Shrink Sleeves

Wrap around pipe sleeve with thermal indicator (ideal for large diameter water pipe where internal welding will take place).  Waterwrap-WAB is known as Waterwrap 1.0-2.0.  

Materials Needed:

1.  Appropriate size Waterwrap WAB shrink sleeve and WPCPIV Closure Patch.

2.  Polyken 939 Filler is needed when pipe wall thickness is 1/4" or greater and is optional when wall thickness is less than that. 

3.  Torch with a regulator that can maintain a broad, bushy, yellow flame.

4.  Propane gas tank, hose and gauge

5.  Standard safety equipment including but not limited to:  gloves, goggles, hard hat, safety shoes

1.  Surface preparation:  Clean pipe surface and adjacent coating of all mud, oil, grease, rust and other foreign contaminants in accordance with SSPC-SP3 Power Wire Brush Cleaning.  Remove all grease contamination by solvent cleaning the pipe and adjacent coating in accordance with SSPC-SP-1.  Clean the full circumference of the pipe a minimum of 4 inches onto the existing coating and lightly abrade this area using Wire Brush or 60 grit approved sand paper. 

2.  Preheat joint area and most primary coatings to approximately 68F minimum.  Under no circumstances shall the Waterwrap sleeve be installed on pipe surface with visible moisture.  For PU coatings, preheat must be in the range of 100F to 140F to ensure ultimate performance of the Waterwrap on the PU.  

Remove the protective release plastic from the coated sleeve.  Center sleeve over the weld area so it is evenly overlapping adjacent pipe coating.  Wrap snugly around the pipe so that the Covalence logo runs around the pipe.  Overlapping ends of the sleeve should align evenly.  Position overlap to permit easy access for installing closure.  Select sleeve width that overlaps onto the mill applied coating by a minimum of 50mm (2") after application.  

For application during cold climate conditions, follow these recommended steps: 

Pipe must be preheated to 122F to 140F.  Preheat with a high output torch.  Shoot for a torch output of 250,000 when shrinking the Waterwrap weld after backfill.  For pipe sizes larger than 40", use four people to heat and apply the shrink sleeve.  For pipe sizes less than 40", two installers can be used for the Waterwrap weld after back fill.  

Both the Weld After Back Fill Waterwrap and the Polyken 939 mastic filler should be maintained at a minimum of 68F until time to install.  This could mean keeping them in a heated vehicle or storage shed.  Flame the edge of the mainline coating before installation of the WAB waterwrap shrink sleeve to remove moisture and preheat the factory applied coating. .

WPCPIV Closure application:

1.  Using a torch, adjust the flame length to approximately 20" to produce a blue tipped yellow flame.  Using the yellow portion of the flame, heat the closure evenly until the pattern of the fabric reinforcement is visible.  With a gloved hand and roller, smooth any wrinkles by working outward from the center.  

Using the torch, begin to shrink the Waterwrap Weld After Backfill sleeve at its center, circumferentially around the pipe using a constant paintbrush motion, until the embossed pattern on the sheet surface has changed to a smooth surface.  

Continue heating toward one end of the sleeve, followed by the other.  During shrink down of the Weld after backfill shrink sleeve, occasionally check adhesive flow with a finger.  Wrinkles should disappear automatically.  Remember to wear gloves.  While sleeve is hot, press or roll overlap and closure area to remove any air voids.  

Sleeve is fully recovered when all of the following have occurred:

Waterwrap has a smooth surface

There are no cold spots on the sleeve surface

Weld bead profile can be seen through the sleeve

After sleeve is cool, mastic flow is evident on both edges

The sleeve has fully conformed to the pipe adjacent coating

The pattern on the backing has disappeared and the backing is a smooth surface

WaterWrap Weld After Backfill Heat Shrink Sleeves

Heat Shrink Sleeves for Weld After Backfill (WAB) 

     Water Wrap with PCI (permanent change indicator) is a two layer field joint coating system designed for corrosion protection of buried large diameter water pipelines operating at ambient temperatures.  The 2 layer construction consists of a visco elastic low preheat adhesive sealant and a thick walled radiation cross linked high density polyethylene with PCI (permanent change indicator). 

     Waterwrap is a wrap around heat shrinkble, ready to fit assembly for the corrosion protection of field girth weld joints in water distribution and transmission systems.  Waterwrap/B is compatible with standard pipe coatings.  Waterwrap can also be used for coating bare, replacement pipe sections and large radius bends.  Waterwrap System-B is designed to be applied with a minimum preheating and is ideal for large diameter pipe.  The installation is carried out directly on the cleaned and dried (preheated) pipe surface.  The use of 939 filler is required when the step down on the weld bead is greater than or equal to 1/4".  The filler 939 is a thick mastic like butyl rubber designed to fill and smooth transition areas.  The semi-tacky composition remains flexible and easily molded in place to conform around irregular shapes.  During installation, the heat shrinkable sleeve is wrapped around the pipe and heat is applied.  The heat activated backing contracts to form a tight fit around the joint eliminating entrapped air and filling the smallest of crevices with high quality, corrosion inhibiting visco elastic adhesive sealant.  The permanently cross linked polyolefin outer layer forms a tough barrier against mechanical damage and moisture. 
     This product does not give off toxic gas vapors, it is safe to use.  This product has a high modulus backing which offers greater soil stress resistance and a great overall performance.  Product is tough but flexible and displays high impact and penetration resistance.  Waterwraps high shrink force optimizes flow and fill of visco elastic adhesive sealant. which brings with it greater long term protection.  Low application preheat makes installation fast and easy.