Replace piping and equipment and get back online safely and quickly with 3D scanning technology

Accurate fit up of replacement piping, equipment, and other components helps minimize downtime. Learn about new improvements in 3D technologies that take accuracy to a new level.

On the surface, the pipeline station refit project seemed pretty standard. An antiquated strainer on a 16-inch line needed to be replaced, and then the line could be returned to service. But this seemingly ordinary project could have gone seriously sideways if not for the help of some new technologies.

Previously, our engineers used a tape measure, level, square, and string to measure the existing installation, and then designed an updated replacement. But with such an approach, we missed discovering an essential fact – that the existing piping wasn’t quite square, but rather two degrees off. It might not sound like much, but if we had proceeded without discovering the discrepancy, the replacement fabrication would not have fitted up in the field. This would have led to additional downtime and costs for rework—all words that no pipeline operator wants to hear.

In such situations, it can be tempting to force the installation to fit. But, as you can imagine, this leads to a whole host of problems:

• It can put dangerous stresses on the pipeline and fittings.
• Putting stress on piping means loading a very powerful spring, which is a safety hazard whenever that spring is released.
• Installation stress on piping can also mean that normal thermal expansion and contraction combine with the misalignment to cause fatigue failures.
• Underground, stressed pipe is vulnerable to stress corrosion cracking (SCC).
• And, if the replacement fabrication can’t be modified on site to fit the pipe, redesigning and reworking the replacement to fit and retesting it can mean a longer shutdown of the line.

Fortunately, HT Engineering was able to sidestep all of these problems, thanks to a little help from our new 3D scanner. By accurately identifying the off angle, we were able to design the replacement piping accordingly. We lengthened and shortened pipe pups and added a slight deflection angle to a butt weld to line up the tie-in flanges. While the team was prepared for field welds, they were not necessary. The piping fit up well, as expected.

3D scanning helps produce better results, faster

As our story illustrates, to replace pipeline station components such as piping, strainers, compressors, and pumps efficiently, a high degree of accuracy is needed in determining the configuration of the existing system before designing and fabricating the replacement. Without that accuracy, pipeline downtime for installation can be unpredictable, and the work not as safe.

3D scanning offers a fast-developing solution to minimizing downtime and maximizing safety. The method uses a device – in our case a shoebox-sized scanner – that mounts on a tripod and measures the location of objects by emitting an array of laser beams. The scanner outputs a “point cloud” Computer-Aided Design model of the system, such as the meter station strainer piping in our example. Back at the office, a designer uses software to align multiple scans from various angles and creates an accurate as-built image of the subject.

With that accurate picture of the existing system, we can design and fabricate a replacement to fit in the real world. Before installation, we can also scan the replacement and verify that it matches the design.

Recent improvements in 3D scanning

While 3D scanning technology has been available for some time, recent improvements are making it much more mainstream and advantageous, allowing more engineers to help their clients achieve better outcomes. These recent improvements include:

• Affordable, practical, field-rugged devices that provide accurate, fast scans
• Computer systems that can store and work with the huge data files the scanners produce
• Powerful software tools that accelerate the use of scanner data with CAD systems and allow engineers to produce results quickly
• The ability to generate a virtual space that engineers and clients can “enter” to tour and take measurements that correspond accurately with the real environment

3D scanning can provide an accurate image of the site, that can then be simplified to allow designers to focus on the essentials. This helps to catch potential problems before they have a chance to impact the project, and supports accurate fit of replacement components, to reduce downtime and costs.

Getting good results with 3D scanning

Clearly, 3D scanning can give you an edge, particularly in the case of updates and upgrades to existing piping systems. And while access to the technology and all its new bells and whistles is increasing, it’s important to remember that having the technology, and having the capabilities to leverage it properly, are two different things. Here are some pointers on getting good results.

• Plan the scan: Good planning to determine scanner positions helps achieve a better outcome. This means it’s typically worthwhile for someone on the pipeline operator’s team to take some pictures of the subject ahead of time, and send those images, along with a site plan drawing, to the survey team. This helps the survey team plan their work efficiently, for minimal disruption of your operations.
• Minimize obstructions: Generally, a higher number of scans, from various angles, including above and below the object, produces a more accurate 3D model. Accordingly, anything such as spare equipment that might obscure the scanner’s line of sight should be moved out of the way before the scanner crew arrives.
• Scan the replacement: Experience has found that it’s a good investment to scan the fabricated replacement part before installation and compare it to the existing configuration to confirm that it will fit.
• Leave time for field modifications: Despite the much higher likelihood of a good fit up with 3D-scanning-based design, you should still be prepared for field modifications when installing replacement piping.
• Look for two competencies: To get the most benefit, you need access to people with two key skill sets. First, they need to be capable of getting the best results from the 3D technology itself and applying it to designing replacement systems. Second, they need to understand the realities of pipeline operation – such as the importance of minimizing downtime and the challenges of piping construction.

There’s even more to gain than a good fit

Getting things right on the first try is obviously a huge advantage for 3D scanning and can save you a lot of time, costs, and headaches on your retrofit project. This new standard for accuracy also opens the door to several other benefits:

• Less field welding: Making it possible for replacement units to be fitted smoothly into the existing pipe can help reduce the need for welding in the field. This can improve the integrity of the line, as work done in the controlled environment of a shop is easier to manage than work done in variable light and weather conditions in the field. Fewer field welds also means less on-site weld and pressure testing.
• Better relations with regulators: Regulatory authorities appreciate the level of certainty that 3D scanning provides. Scans of the original installation and its replacement can reassure them that installation stresses have been minimized. Remember to ask your engineering firm for copies of the scans, and show them to the regulators when the subject comes up.

Seeing is believing

In the pipeline sector, 3D modeling is key to more accurate replacements and upgrades of equipment, resulting in less need to force pipe to fit, less need for field welds, and a faster return to service. And that’s good news for pipeline operators, engineers, and regulators alike.

To learn more about how 3D scanning helps you achieve accurate fit-up of replacement piping, equipment, and other components, as well as recent improvements in 3D scanning technology and how it is being used, please contact us today.