Multi-Pipe Pull Throughs

 

Managing Multiple Pipelines in a Single Bore: Why Spacing Matters

Pulling multiple pipelines through the same bore hole introduces a unique set of challenges for any construction crew. Once those lines are in motion, the question becomes: how do you keep one pipeline from abrading another? How do you prevent collisions as the pipes shift, flex, and—at times—behave more like spaghetti noodles than rigid steel?

These concerns become even more critical at the girth welds. The weld profile naturally creates a high point on the pipe, making it especially vulnerable to damage if adjacent lines come into contact during installation or over the life of the pipeline.

That’s where our BBS (Bundled Bumper System) comes into play.

The BBS system creates a one-inch bumper around the pipeline, effectively spacing lines apart as they are pulled through the bore. While larger spacers can be manufactured, more than a decade of field experience has shown that a one-inch separation is more than sufficient for the vast majority of applications.

By maintaining consistent separation, BBS prevents pipelines from abrading, bumping, or damaging one another—both during installation and after the lines are in place. Just as importantly, once the pipelines reach their final resting position, the spacing created by BBS allows soil to settle naturally between the lines. This ensures your cathodic protection (CP) system has unobstructed access to 360 degrees of each pipeline, helping maintain long-term corrosion protection.

When multiple lines share a single bore, proper spacing isn’t just a nice-to-have—it’s essential. And with the right system in place, it’s one less thing your crew has to worry about.

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.