ASME BPVC Section VIII deals with the design and construction of pressure vessel. Tau Engineering specializes in "Design by Analysis" pressure vessel work following both ASME BPVC Section VIII Div 2 and Div 3, using advanced FEA technologies. Our ASME BPVC Engineers have successfully completed a broad range of design and analysis work on many pressure vessels and containers in both subsea and topside equipments. Tau Engineering's expetise in FEA analysis include:

• Elastic analysis for plastic collapse protection, including stress linearization, stress category classification and local stress analysis:
• Plastic stress analysis, including limit analysis and elastic-plastic analysis and local plastic analysis;
• Buckling analysis, including elastic buckling, nonlinear buckling, and impefection analysis;
• Fatigue analysis, including elastic method, elastic-plastic method, and weldment fatigue analysis;
• Ratcheting analysis, including elastic method, elastic-plastic method, thermal ratcheting analysis;
• Fracture mechanics design for life prediction based on ASME BPVC Sec VIII and API 579-1/ASME FFS-1;
• Thermal stress analysis, for high temperature and high pressure equipment;
• Hydrostatic shell test analysis, using both linear-elastic or elastic-plastic method;

Tau Engineering applies the mix of the above analysis to determine equipment rated capacity, predict equipment design life and/or failure limits, and optimizate the equipmen. We are also able to develop new analysis method specified by customer based on our advanced understanding in FEM and various codes.

FEA analysis has historically helped drilling operators and rig designers in their techanical challenges. Stress and vibrational analysis are often required for topside and subsea drilling equipment, e.g., derrick structure, drill string, riser, drill bit, BOP and wellhead. Tau Engineeering has successfully designed various drilling riser, peripheral lines (choke, kill and bosster), and BOP annular in the past years. We used advanced FEA tool to design these equipment in accordance to API 6A, 16C, 17F and other API or DNV codes. These equipment has been successfully deployed.

HPHT equipment is classified when pressure rating great than 15 ksi (103.43MPa) or a temperature rating greater than 350 ºF (177 ºC). HPHT condition might affect the design and analysis method. For example, High pressure could affect the fluids interaction with materials, as the partial pressure of H₂S goes up when the design pressure increases. Elevated temperature typically accelerate corrosion rate, failure mode, and induces creep. High temperature also changes the material's mechanical properties, including Young's modulus, strength, fracture toughness. Elevated temperature might also affect the properties of seals and bolts. Therefore, the design and analysis of HPHT equipment requires special considerations.

API Techanical report 17TR8 provides the general design guideline for HPHT equipment in oil/gas industry. API 6X, ASME BPVC Div 2 and Div 3 are the three design methods that API 17TR8 suggest for different pressure and temperature rating. For HPHT equipment, ASME BPVC Div 3 are suggested with global plastic, ratcheting, fatigue, and fracture mechanics evaluations.

FEA models have been widely used on the design of subsea process equipment, such as, valves, subsea wellheads, downhole tools, subsea manifolds, processing piping , and other process equipment. The structural integraty under operational or test conditions must be ensured and assessed by designers. ASME BPVC VIII, API 6A, and API 17D are the typical standards used in subsea process equipment design. Pressure loading, thermal-mechanical loading, seawater corrosion, cathodic protection, and vibration need to be considered during the design and analysis of the subsea process equipment. Tau Engineering can help you in the design and risk assessment of the subsea equipment.