HIGH-TEMPERATURE CREEP ASSESSMENTS
Extend the Life of Your Critical Assets
High-temperature creep occurs when metals are exposed to prolonged stress and high temperatures, resulting in gradual and irreversible deformation. This issue is commonly found in oil and gas, petrochemical, power generation, and other related industries, where critical equipment is exposed to extreme operational conditions and high temperatures. Left unchecked, creep can lead to material degradation, causing cracks, voids, and potential equipment failure.
At Equity Engineering, we combine our industry knowledge with an extensive database of creep rupture, rate, and ductility data to correctly evaluate high-temperature equipment for creep damage. These specialized creep assessments will provide practical recommendations to support informed decisions and improve equipment reliability.
Benefits
Prevent costly failures
Optimize maintenance plans
Extend asset lifecycle
Comply with industry standards
What is Omega Creep Testing?
Omega creep testing and analysis measures strain rates and predicts critical operating limits. Unlike traditional methods, the Omega approach accommodates multiple test conditions and accelerates analysis for faster results.
Our metallurgical experts use the MPC Omega Method to analyze material creep rates, the creep ductility Omega parameter, and rupture time to accurately predict remaining life. These tests help prevent costly equipment failures and the unnecessary replacement of fired heater tubes.
Equity Engineering’s Advanced Creep Assessment Services
We apply our expert knowledge to correctly perform specialized creep assessments including adjusting material creep properties to account for aging, carburization, and softening (spheroidization, graphitization). We integrate API 579 guidelines and state-of-the-art analysis to deliver practical recommendations that will extend the life of your fired heater tubes and other critical equipment.
Our services include standard and advanced creep analysis:
- Validate material properties when extrapolating temperature and stress and detailed results for samples that deviate from the expected behavior
- Generate Omega and Larson-Miller creep properties for many alloys (e.g., 20-32Nb, HP microalloy/25-35MA, 35-45MA, and many others)
- Identify fired heater and other high-temperature equipment reliability problems
- Statistical distribution of metal temperature and other temperature data (skin TI and infrared) to reduce conservatism
- Create practical inspection programs and repair strategies
Best Practices for Omega Tests
When looking at conducting an Omega creep test, it is important to remember that smaller and lower-cost labs may not provide a comprehensive analysis. In many cases, you may need to select specific conditions or specify types of analyses to obtain meaningful results. If you have a sample to test, Equity Engineering is a one-stop shop for advanced analysis and material testing.
By default, all Equity Engineering Omega creep assessments include:
- Larson-Miller analysis in addition to Omega
- Metallurgical assessments (composition, optical, and/or SEM micrographs, micro-hardness, and occasionally tensile, Charpy, and bend testing)
- Tests in both the Longitudinal and circumferential direction of the tube
- Target test times that run a minimum of 1000 hours under multiple operating conditions to minimize conservativism
- Testing and retesting of spare specimens if ruptures occur too quickly
- Interval reports throughout the Omega testing process to support timely decisions on tube replacements
Case Study: Remaining Life Assessment Mitigates Potential for Creep Failure
Issue: During an outage, a bulging (diameter increase) was observed near the bottom section of radiant SMR tubes while performing strapping measurements. The next opportunity for a planned replacement was multiple years away, and the client was concerned about premature creep failure.
Solution: We reviewed the infrared scan, pyrometer data, and diameter measurements and helped select a tube for extraction. We provided weld repair guidance for re-welding onto the service-aged and embrittled HP-microalloy material. An Omega method creep test was performed on the removed tube sample, and we developed Omega and Larson-Miller creep properties for the HP-microalloy material. The remaining life assessment used that data to perform calculations on the past operating data and process-side operating data as a basis for the temperature distribution.
Result: The remaining life of the radiant coil was shown to be sufficient to allow a planned retube at a convenient future outage, without a near-term operational disruption. After the project, the client received material properties and ongoing support to continue updating the remaining life calculations with the new operating data
Why Equity Engineering?
The engineers who will conduct your creep test are the expert authors of several industry documents (multiple WRC bulletins, including WRC 541), the main technical contributor for material property data to API 530, and significant contributors to API 579 Part 10.
