1. Main Problem Identified: The drum was originally designed for −6 psig vacuum pressure, but certain operating scenarios could impose up to −13 psig external pressure. A formal assessment was needed to determine whether the external design pressure could be increased to −13 psig at the same temperature.

2. Approach: The vessel was modeled in COMPRESS and evaluated using ASME Section VIII, Division 2 rules via Mandatory Appendix 46 for a Division 1 vessel. Component MAWP-External checks showed the cylindrical shell governed, and acceptability was confirmed at the target external pressure.

3. End Results: From the assessment results, rerate forms per API 510 and a new nameplate were created to document the increased vacuum condition. The nameplate was affixed next to the existing ASME nameplate to complete the rerate process.

1. Main Problem Identified: Degraded shell section near large inlet nozzle required structural repair while maintaining vessel integrity and code compliance.

2. Approach: Designed and specified a flush insert plate per API PCC-2 and NBIC Part 3 for ASME VIII-1 equipment; coordinated NDE, material certification, and weld procedure qualification per ASME IX.

3. End Results: Developed a complete field-executable repair plan with dimensional tolerances, WPS/PQR specs, 100% VT/PT/PAUT inspections, and NBIC R-1 form compliance; no hydrotest required due to validated PAUT results.

1. Main Problem Identified: Corrosion damage at lower shell courses of a tall tower required window cutouts to replace damaged shell sections and subsequent postweld heat treatment.

2. Approach: FEA-based assessment of column stability and shell deflection under wind and dead load during cutout and PWHT; evaluated per ASME VIII-2 and time dependent properties for creep buckling.

3. End Results: The window cutout segments met buckling and fit-up criteria with the material removed. Recommended full encirclement heating for thermal stress control. Confirmed structural stability without crane support during 360° PWHT at temperature.

1. Main Problem Identified: The client experienced recurring cracking at the fermentation tank roof-to-stiffener fillet welds, concentrated near rafter-gusset “rat-hole” openings and persisting despite prior repairs that re-cracked in roughly two months..

2. Approach: Executed a four-phase root-cause investigation that included site visits to two of the client facilities, detailed field observations, and data review. The team verified API-650 and structural calculations, performed finite-element analysis using the ASME VIII-2 Structural Stress method, evaluated mixer-load effects and metallurgy/welding, and iteratively developed repair/redesign concepts.

3. End Results: The investigation concluded fatigue failure from pressure cycling as the root cause and showed the as-built configuration had an available fatigue life on the order of 50–60 days. Refined Engineerings’s recommended modifications increased predicted fatigue life to >50 years.

1. Main Problem Identified: Evaluate the design and installation of a new 18-inch nozzle with an insert plate at the top of an acid storage vessel. Mixed materials in the reinforcement zone and uncertainty that final piping loads could exceed preliminary values created risk of local overstress.

2. Approach: Performed alteration calculations per ASME and NBIC rules. Evaluated the nozzle and local insert plate’s capacity for piping loads using WRC Bulletin 537 and hand calculations.

3. End Results: Design met all ASME, NBIC, and client spacing/stress criteria, with high capacity for external piping loads. The configuration was fabricated, installed in the existing vessel, and successfully placed in service.

1. Main Problem Identified: Two large cracks were found on the incinerator stack; a full encasement box was proposed for repair.

2. Approach: Nonlinear elastic-plastic collapse and buckling evaluation using ASME VIII-2, Part 5, with ABAQUS FEA. Included wind and dead load modeling, heat transfer to determine metal temperature, and buckling analysis.

3. End Results: Leak box design confirmed structurally adequate with margin for collapse and buckling for all load cases with wind and dead load combined. Design approved for installation.

1. Main Problem Identified: The site needed to determine if two high pressure heat exchangers could be rerated to higher pressures without full replacement. Key constraints included existing Class 1500 flanges that do not meet the required pressure–temperature rating.

2. Approach: The exchangers were re-evaluated to the original code of construction using design-by-rule calculations in COMPRESS per ASME Section VIII-1 and TEMA for tubesheets, complemented by design-by-analysis (FEA) per Section VIII-2 for the channel body..

3. End Results: The rerate was feasible provided the Class 1500 flanges are replaced with new flanges meeting current ASME B16.5 ratings; tubesheet and channel cover thicknesses were adequate. A new hydrotest was required after the replacement of the flange. However, given the age/vintage of the existing steel and process conditions, additional evaluation to check for hydrogen damage was required for the hydrotest condition.

1. Main Problem Identified: Aggressive shell erosion and through-wall failures near the old air grid of a FCC Regenerator. Erosion and through wall failures continued despite prior lap patch repairs.

2. Approach: Develop basic leak box design per ASME PCC-2 to enclose the existing lap patch repairs. Performed elastic-plastic FEA using ABAQUS to evaluate structural load capacity of the box in the event that the existing shell metal underneath the enclosure box was completely erroded away.

3. End Results: Verified performance of a refractory-lined leak box design to resist erosion while under pressure, temperature, and dead loads. The leak box successfully eliminate further leaks until the planned turnaround was reached months later.

1. Main Problem Identified: Cracking discovered at the weld between the inlet nozzle and shell of a stainless steel deaerator. Similar defects had been discovered at similar locations on other deaerators for the client.

2. Approach: Working with a metallurgical lab, destructive testing was performed to confirm the damage mechanism of the crack. Reviewed existing operating procedures and the physical characteristics of the inlet nozzle as well.

3. End Results: The damage mechanism was determined to be Caustic SCC from a combination of a poorly designed pH control system and non-standard hopper design. Redesigned the nozzle-hopper configuration to lower over-constraint and upgraded the local metallurgy since the pH control system was not readily modified.

1. Main Problem Identified: High-pressure low-temperature separator built to ASME Section VIII, Division 2 required a repair plan and certification by a licensed professional engineer to ensure compliance with NBIC and ASME Section VIII-2.

2. Approach: Reviewed User’s Design Specification (UDS), Manufacturer’s Data Report (MDR), PWHT procedures, weld overlays, and insulation installation methods in accordance with NBIC NB-23 Part 3 rules. Developed the details of the repair plan in conjunction with client specifications and requirements.

3. End Results: The PE certified repair plan was provided to the client as complete and code-compliant; approved for implementation under National Board Inspection Code guidelines. Repairs were completed and the vessel was put back into service successfully.

1. Main Problem Identified: Piping system operating at pressures exceeding original design; reevaluation needed to avoid costly flange replacements.

2. Approach: Performed ASME B31.3 and Section VIII Appendix 2 evaluation using COMPRESS software. MAWP determination for each flange under updated operating conditions. Corrosion allowance and pipe schedule reviews for compliance.

3. End Results: Most flanges acceptable for the increased operating pressure. One flange size limited to reduced corrosion allowance for compliance. Avoided widespread replacement while maintaining code compliance.

1. Main Problem Identified: Rerating of storage tank required for elevated vacuum pressure without internal liquid, which could otherwise result in tank bottom uplift or overstressing.

2. Approach: Nonlinear elastic-plastic FEA using axisymmetric modeling in Abaqus, per API 650/653 and API-579-1/ASME FFS-1. Evaluated whether stress/strain or practical deflection limits were exceeded.

3. End Results: Tank bottom predicted to deflect upward by a few inches, but all stresses/strains remained within allowable limits. Operation at increased vacuum condition is acceptable without liquid present.