Resources
Conventional HRSG Tube-to-Tube Tie-In (Butt Weld)
Welding Method:
- Conventional tube-to-tube tie-ins are performed using butt welds. This method requires careful alignment and preparation since butt joints demand complete penetration to ensure structural integrity.
NDT Requirements:
- Butt welds typically require more complex non-destructive testing methods such as:
- RT (Radiographic Testing): This involves using X-rays or gamma rays to inspect the weld for internal defects. It requires specialized equipment and trained personnel.
- UT (Ultrasonic Testing): This method uses high-frequency sound waves to detect flaws within the material. It also requires skilled operators and can sometimes lead to difficulties in interpreting results.
- Both RT and UT testing can take a significant amount of time and require setup and restricted areas, which can interrupt ongoing work in the field or fabrication shop.
Complications of Testing:
- Radiographic and ultrasonic testing results can be more complicated to interpret due to the nature of the data they provide. Operators must have sufficient training to distinguish/discern between acceptable variances and defects, which can sometimes lead to delays in results.
Time Efficiency:
- The time-consuming setup and detailed interpretation of RT and UT mean that the overall process can take longer, potentially causing downtime in the fabrication process or field operations.
TTT Product Line (Lap Joint Connection)
Welding Method:
- TTT utilizes a lap joint connection, which simplifies the welding process. The lap joint requires only fillet welds, making alignment and execution faster compared to butt welds.
NDT Requirements:
- For TTT lap joints, non-destructive testing is conducted using:
- PT (Liquid Penetrant Testing): This method involves a two part application: applying a dye and then a developer to the surface to expose any cracks or defects. It's relatively quick and straightforward.
- MT (Magnetic Particle Testing): This test detects surface and near-surface flaws in ferromagnetic materials by using magnetic fields. It's efficient in identifying defects and typically easier to read.
- VT (Visual Testing): A simple inspection method that requires minimum training and quickly checks for visible defects.
- This combination of testing methods allows for faster inspections, with results being more straightforward to interpret.
Time Savings:
- TTT lap joint connection combined with PT, MT, and VT testing is generally quicker to execute and analyze than the conventional methods. This leads to significantly less downtime during the fabrication or repair process, allowing for more efficient workflow.
- The simplicity of the tests means that they require less specialized equipment and training, which can be advantageous in the field or during fabrication.
Impact on Operations:
- Due to the quicker inspection process and less complicated interpretation, TTT’s approach minimizes disruptions to ongoing work. This is particularly beneficial in environments where multiple operations occur simultaneously or schedules are tight, as it won’t interrupt other critical tasks.
Conclusion
In summary, TTT lap joint connection stands out as a quicker and safer alternative to conventional butt welds in HRSG tube-to-tube tie-ins. The use of simplified NDT methods like PT, MT, and VT not only streamlines the inspection process but also reduces downtime in the field and fabrication shop. This results in a more efficient workflow, less complicated testing and interpretation, and an overall enhancement of productivity and safety within the operations.
Patent Numbers
US PATENT NO. US 12,135,177- NOVEMBER 5, 2024
US PATENT NO. US 12,130,101- OCTOBER 29, 2024
VIETNAM-