This article describes a case study of a high-end refinery using mechanical tube plugs to isolate leaking tubes in a heat exchanger and get the unit back online the same day.
Torq N’ Seal® mechanical tube plugs were originally designed for use in Nuclear and Offshore Oil applications where success is critical. This engineered solution for how to plug heat exchanger tubes offers significant benefits over welded or hydraulic plugs due to their simple, safe, and effective installation.
A refinery with a highly delicate process was experiencing tube leaks in an exchanger for which any fluid mixing was unacceptable to the process. Thus, as soon as the chemistry was detected to be off expected norms, the exchanger would be brought down until the leaking tube could be identified and plugged. Immediate turnaround was the key and Torq N’ Seal® heat exchanger plugs turned out to be the solution.
Benefits of Torq N’ Seal® Mechanical Tube Plugs
- Fast, installed by hand in less than 60 seconds.
- Simple, no hydraulics or welding required.
- Effective, sealing up to 7,000 PSI (480 BAR).
- Compliant, with ASME PCC-2, ASME B31.3, ABSA CRN and more.
- Reliable, proven track record.
- Safe, no damage to tube ends or tube to tubesheet joints.
- Removable, to re-tube or return tubes to service.
Historically, this refinery would use welded tapered plugs, but this approach carried significant downsides. The first and foremost of these was safety. Any welding project involves high heat and volatile chemicals, thus there are significant process steps required to ensure safe operation in welding applications, as there should be. This would add significant time for approvals and coordination. Additionally, welding creates a heat affected zone that can deform the tubesheet and cause additional leaks to adjacent tubes or tube to tubesheet seals. In summary, welding tapered plugs comes with both safety and process risks.
The upside to welding though is high confidence level. The process in question required a confident seal, that is where Torq N’ Seal® mechanical plugs were able to help. With sealing capacity up to 7,000 PSI, the Torq N’ Seal® plugs came with the same high confidence level as welding. Additionally, installation was fast, simple, and effective when compared to welding tapered plugs. Installed by hand with only a torque wrench, Torq N’ Seal® is completely safe to operate. The steady, controlled expansion sealed the leaking tube rapidly while keeping adjacent tubes and tubesheet ligaments secure.
The refinery first tested the plugs on a simple condenser in a different part of the process, experiencing exactly the expected results, successful seal of the tube. The plugs were tested with Nitrogen and put into 6-month service, after which the exchanger was opened and the seal was verified again. Next, when the delicate process exchanger went down, they were able to immediately install Torq N’ Seal® heat exchanger plugs and get the exchanger back on-line the same day. Following this successful project, the refinery plans to use Torq N’ Seal® on all tube plugging projects moving forward.
For more information, visit www.torq-n-seal.com/bic, call (201) 641-2130 or email sales@torq-n-seal.com
