Tanks and Pressure Vessels.
Sometimes, the rule book is wrong. Analysis conduct at BEAR has actually resulted in new ASME Piping Codes. Since our company was founded by a refinery engineer, BEAR has very deep roots in the oil, gas and pipeline industries.
In addition to our extensive Coke Drum services, BEAR engineers can provide analysis for any mechanical component at a refinery or power plant. BEAR has crucial expertise in evaluating existing equipment using a variety of methodologies including API 579, British Codes R-5 and R-6, Finite Element Analysis, etc.
The failure of this 30-inch diameter steam line, operating at 900 psi and 1000 degF, shutdown the Mohave, California power plant. The failure occurred along a longitudinal weld in the pipe. BEAR engineers determined that although the weld metal was stronger than the pipe steel at room temperature, the creep, or high temperature deformation rate of the weld metal was 10 times greater than the pipe's base metal. This mismatch led to failure after 10 years of operation. The ASME Piping Codes have been changed to prevent this type of failure based in part on analysis work performed by BEAR on this failure and others.
hydrogen reactor vessel
BEAR engineers analyzed cracking in the ring groove of the top head of this 3000 psi, 8-inch thick, 10-foot diameter, 50-foot tall hydrogen reactor vessel. The stress analysis indicated that the cracks would stop growing as they expanded into low-stress regions of the head, away from the ring groove. The vessel was returned to service.
BEAR engineers determined that the transition section of a 300-foot stack at a refinery in Kazakhstan could be safely heated to 1250 degF to reduce residual stresses in the welds. The diameter of the stack changed from 10 feet to 3 feet at the transition section. The heat treatment was carried out successfully.
Scanning of Drum's Internal Surfaces
BEAR has developed new technology for scanning and inspecting internal surfaces of coke drums. The new method allows scanning through the top and bottom heads between cycles in 1 hour (the scanner is stationary) and is so accurate that you can see most welds in the scan. Scanning through both heads eliminates all blind spots and provides scan data for the top head and conical section.
Color contour plots of the "rolled out" surface of the coke drum (vertical and circumferential profiles) and the scanned data points (densities up to 8 pts per inch) are provided to the customer in any standard data format. Custom formatting is also available. The results can be used to track drum deformation over time, perform a finite element analysis, and estimate a drum's remaining life.
BEAR also offers a full range of Coke Drum analysis and instrumentation services:
* Finite Element Analysis * Crack Initiation/Growth * Life Assessment * Thermal Couple and Strain Gage Instrumentation
"Turn-Key" thermal couple or strain gage data acquisition systems provide statistical histograms of thermal or strain loading and calculate damage rates and remaining life.
BEAR's damage accumulation models predict remaining life using either thermal couple or strain gage data with the same accuracy.
BEAR's Drumsoft Software
BEAR's user-friendly Drumsoft software allows customers to plot radial variation along any vertical section or any circumferential band. Complete Drum Scan data is provided to the customer on a CD in ASCII format for easy access and archiving for future use.
Coke Drum FEA
BEAR can perform complete finite element analyses of coke drums using the true geometry of the drums derived from laser scan data and field measured dynamic temperature, strain and/or pressure measurements. Combining the resulting stresses with those due to the weight of coke hanging on the drum's wall allows BEAR engineers to assess the remaining life of your coke drums as a function of operating conditions.
BEAR's software can create contour plots of radius variation to allow for the easy visualization of shell bulges and out-of-roundness. These plots can also allow for simple comparisons to prior scans.
high resolution vit photographs
On the left is a photograph taken from a drum video showing a liner weld patch (upper weld) and a circumferential weld (lower weld). The VIT video camera used by BEAR allows for very high resolution closeups.
BEAR can also measure crack growth data at operating temperatures using service exposed material and perform detailed fracture analysis at our laboratory in Berkeley, CA.