In Oil Sands SAGD (Steam Assisted Gravity Drainage) operations, steam is injected into underground bitumen deposits to lower bitumen viscosity, allowing it to flow. Depending on the design of the facility, the steam distribution system (SDS) can include hundreds of meters or even kilometers of piping/pipeline transporting steam from the once through steam generators (OTSGs) to the well pads. The OTSGs and pipelines in SDS have been identified to undergo damage and failure after being in the service for few years. This thesis reports the failure investigations conducted on OTSG and SDS pipelines with the morphology, distribution and features of the damage identified. The associated process conditions, potential damage mechanisms identified, and their contributing factors are also reported. Once through steam generators boiler tubes analyzed experienced localized metal loss in the form of pitting corrosion, under deposit corrosion, micro-galvanic corrosion and, caustic and acidic attack from the operations. Some OTSG tubes have been found to not adhere to the required material composition expected for ASME SA-213 T11 standards: high Mn, high C, and low Cr. Sections of an HP-SDS pipeline have been ascertained to undergo pitting corrosion, crevice corrosion in the form of under-deposit corrosion, flow assisted corrosion and micro-galvanic corrosion. Results from the lab scale experiments conducted to provide an increased understanding on passivation of steels used in the SAGD process conditions are also presented. Recommendations in terms of (a) design and operating factors, (b) environment and operating factors and (c) manufacturing, fabrication and assembly factors to lower the number of failures and reduce the rates of degradation identified are provided.