Category Archives for In-Service Inspection
Acoustic Emission Testing – Data Analysis
The data obtained from an acoustic emission test of a pressure vessel are analyzed to determine the existence of flaws and their locations in the shell of the vessel. Accurate analysis of the data is highly dependent upon the expertise … Continue reading
Acoustic Emission Testing – Physical Principles
Sonic impulses are emitted by a flaw in a ductile material subjected to a gradually increasing applied stress, due to the release of strain energy in the intensified stress field associated with the flaw. The release of strain energy creates … Continue reading
Acoustic Emission Testing (AE)
AE was developed to assess the integrity of pressure-containing equipment in the nuclear power industry. Acoustic sensors are attached to the O.D. surface of the equipment to detect and locate flaws in the material during a pressure test. AE can … Continue reading
Acoustic Emission Testing – Acoustic Sensors and Instrumentation
Most acoustic sensors used for acoustic emission testing of pressure vessels employ piezoelectric ceramic elements that convert the stress waves (i.e., acoustic emissions) propagating through the vessel shell into electrical impulses. These sensors are usually attached to the vessel shell … Continue reading
Inspection of Spheres
In general, the practices that apply to pressure vessels also apply to spheres although the techniques may vary. The tall legs necessary to support spheres should be carefully inspected to determine the condition of the fireproofing and the rain seals. … Continue reading
Reactors External Inspection
1. Nozzles Visually inspect gasket faces if opened, ORJ gaskets and bolting material. On vessels with pressure sealed gaskets check for distortion, corrosion, and cleanliness. 2. Shell a. Obtain UT thickness measurements at representative locations on shell and heads. b. … Continue reading
Reactors Internal Inspection
1. Inspection Ports Obtain measurements at corrosion reference points on reactor shell. Inspect for corrosion or scale at these locations. Loose scale on the bottom head is probably a combination of scale and catalyst. This scale can cause corrosion and … Continue reading
Pressure Vessels Inspection
1. External Corrosion Horizontal drums resting on concrete support saddles frequently corrode externally in the area of the saddle. Inspect the water seal at the edge of the concrete If evidence of corrosion exists, it might be advisable to lift … Continue reading
Distillation Columns Internal Inspection
1. Safety Entry of a column can be made only after the approved, signed entry tags are in place on the column. Safety rules in effect at the vessel must be observed. Inspectors must not work alone in vessels but … Continue reading
Distillation Columns External Inspection Prior to Entry
1. Support and Foundations Distillation columns are usually supported by a cylindrical skirt which usually s fireproofed inside and outside with concrete, brick, or other insulating material. Inspect the fireproofing material carefully for evidence of cracking, spalling, or defective seal … Continue reading