Tower Crane Collapse
Tower Crane Collapse A 300-ft tower crane collapsed onto the intersection of two major streets in downtown San Francisco during the morning rush hour. The accident fatally injured four crew members on the crane and the driver of a bus on the street below. Twenty-two pedestrians were also injured by falling crane pieces or flying […]
Fastener Failure
Fastener Failure – Creep Rupture This case study details the failure of five threaded rods from a support system within a high-temperature furnace. The furnace operated at approximately 1250F, and the rod material was type 310 stainless steel. The objective of the evaluation was to determine the failure mechanism for the threaded rods. The work […]
Failed Boiler Tube
Failed Boiler Tube This case study follows the investigation of a leak in a lateral water wall tube from a coal-fired boiler. The analysis determined the failure mechanism that caused the leak and identified possible operating conditions that would have caused this type of failure. The tube material was plain carbon steel. A fissure in […]
Leaking Chemical Storage Tank
Leaking Chemical Storage Tank A chemical storage tank at a manufacturing facility began to leak trace quantities of the chemical from the tank into the chemical containment area surrounding the tank. The leaks were found to be due to numerous small cracks in the type 316 stainless steel shell (wall). The cracks were located about […]
Perforated Plate Failure
Carburization This case study investigates the failure of multiple type 304 stainless steel perforated plates from a natural gas fired boiler. The plates were part of a baffle for an exhaust duct that was expected to operate between about 1100 – 1200°F. The objectives of the investigation were to determine the failure mechanism for the […]
Fire Protection System Leaks
Microbiologically-influenced Corrosion The fire protection (i.e., sprinkler) system in a commercial building developed multiple leaks. This system was a wet fire suppression system where the distribution pipes are filled with water at all times. A section of the pipe containing a pinhole-sized leak was removed and submitted to the laboratory for analysis. The pinhole leak was […]
Failure of Inlet Pigtail Pipes
Failed Pigtail Pipes This case study details the failure of recently replaced inlet pigtail pipes for a hydrogen reformer furnace. The pigtail connection to the catalyst tube consisted of a ASME A-335 P22 pipe welded to an Incoloy 800HT weldolet. The weldolet was joined to the catalyst tube, which was an HP Modified cast heat-resistant […]
Cracking Capacitors
Several printed circuit board (PCBs), each with 5 multilayer ceramic capacitors (MLCCs), were evaluated to characterize the capacitors. Each PCB was about 1 in. by 1 in. square. Four of the MLCCs were parallel to one edge of the PCB, and one MLCC was oriented at 90° to the others. Some of the capacitors had […]
Fire Inside Steel Chamber
Fire Inside a Stainless Steel Chamber A fire occurred inside a three-story stainless steel chamber for capturing airborne particulates. To determine the extent of damage to the stainless steel material, an investigation was carried out to characterize the condition of the wall and ceiling materials. The goal of the evaluation was to determine what material […]