Case Study

Double Hump Girth Weld Sleeve: Reinforcing Natural Gas Line Corrosion with Custom Ingenuity


Two-For-One Ingenuity: Custom “Double Hump” Girth Weld Sleeve Reinforces Corrosion on Natural Gas Line

When it comes to pipeline repair, innovative measures are often required. In fact, sometimes an operator will reach out to Allan Edwards for assistance or to consult on a repair even if they are not certain whether Allan Edwards, or anyone, can provide the skills and materials necessary to remedy the issue. One such instance occurred in March of 2023 when a pipeline operator contacted Allan Edwards enquiring about a solution for a corrosion feature that had begun to form near two girth welds on a 26-inch natural gas pipeline in Kentucky. The ideal solution would be one that minimized or eliminated downtime so that the pipeline could continue service without interruption.

Setting The Stage

Because of its prevalence, corrosion is often cited as a top cause for failure in natural gas pipelines. In this case, the defect’s proximity to two separate but closely positioned girth welds made the operator unsure whether reinforcement with a steel sleeve was even possible. The geometry of the pipe meant that a standard half sole sleeve could not be used, and the proximity of the two girth welds prohibited installation of a typical girth weld sleeve. Fearing that a custom fix could take weeks to design, produce, and implement, the operator lobbed a hail Mary to Allan Edwards. Luckily, developing unique solutions is something that Allan Edwards has dealt with many times throughout 76 years of providing pipeline repair solutions to the industry.

A Custom-Manufactured Solution

After a brief back-and-forth between Allan Edwards account executives, engineers, and the operator to confirm measurements and other key details, Allan Edwards determined that outfitting the repair zone with a double hump, 40-½” long girth weld sleeve was the best path forward to ensure sufficient reinforcement while also curtailing down time. And so, with the purchase order signed and received, and the measurements sorted, the Allan Edwards team went to work.

Despite a fix on paper and a green light from the customer, several obstacles remained. Because of the unique positioning of the anomaly near two girth welds, the sleeve had to be custom manufactured, which came with its own set of hurdles. First, an engineering drawing was generated to ensure all dimensions of the sleeve would match the geometry of the pipe joint and corresponding girth welds. Once the specifications were known, the sleeve could be manufactured. Outfitting the girth weld sleeve with the second hump required a creative series of steps during layout to ensure that both girth hump features matched the provided dimensions and fit in close contact with the pipe surface for optimal reinforcement. In addition to some out-of-the-box thinking on the design, the production process also required a modified rolling process and specialized tools to help ensure the installation procedure was streamlined in the field. Once the production challenges were overcome, Allan Edwards shipped the sleeve to the jobsite without issue, allowing the operator to complete the repair with no product loss or downtime.

The Value of Experience

Every so often, a customer brings an issue to Allan Edwards that requires an unconventional approach to solve. Allan Edwards’ greatest strength is the ability to leverage more than 75 years of industry experience to provide customers with everything necessary to keep product flowing safely. In this instance, Allan Edwards was able to design, produce, and ship a custom-manufactured sleeve to reinforce corrosion near two girth welds. Significantly, only six days elapsed between the purchase order’s issue and the arrival of the sleeve at the jobsite. Thanks to this creative approach, the operator was able to keep flow uninterrupted and eliminate costly downtime.