New Practice for Examination of Off the Road (OTR) Wheel and Rim Assemblies on Off-Road Machinery at Site
1. Scope
This Standard sets out the requirements for the identification, preparation, inspection, and non-destructive testing of off-the-road (OTR) wheel and rim assemblies for off road machinery at site. It is suited for wheel assemblies and rim assemblies of no less than 622 mm (24.5 inches) diameters. A rim and its components act in the same manner as a pressure vessel. The release of large quantities of energy in an uncontrolled manner poses risk to nearby personnel and property. The effects of rim assembly components, where there is metal to metal contact, can create cracking and pitting, leading to failure. Disintegrated pieces of the rim assembly have been thrown considerable distances. Current practices utilize magnetic particle method of inspection. Typically, OTR assemblies are shipped off site to an OEM for inspection. The OTR components are sandblasted prior to the magnetic particle inspection. If the OTR assembly passes the criteria, the assemblies are shipped back to site. If they fail, they are either repaired or scrapped. This whole process creates logistical challenges and creates unnecessary costs to the asset owner. On several occasions, OTR assemblies have suffered failures worldwide. To minimize this element of risk, inspections and certifications are considered necessary. This standard describes a new proposed practice for electromagnetic methods for examination of OTR assemblies. This practice addresses the need to detect surface breaking flaws electronically and to have the ability to size accurately any surface breaking cracks found on OTR assemblies faster and more effectively than other methods. Eddy-current surface arrays are seeing increasing use throughout industry for the detection of surface breaking flaws in conducting materials. Example applications include examinations of pipelines, bridges, engines, aerospace structures, and any conducting material for surface breaking flaws including cracks. In addition, model-based methods are being used to size cracks accurately found lock ring grooves where there is metal to metal contact. As visual interpretation and magnetic particle inspection methods of a surface breaking discontinuity on OTR assemblies is the normal analysis, the colors and 3D images that are provided with Eddy Current Array technique help with visualization and, therefore, are absolutely invaluable in such circumstances. This practice will help to standardize the use of this nondestructive testing approach and can also be used as part of a predictive-based monitoring program.
Keywords
magnetic inspection; NDE; Off-the-Road; rim inspection; wheel inspection
Rationale
Current practices utilize magnetic particle method of inspection. Typically, OTR assemblies are shipped off site to an OEM for inspection. The OTR components are sandblasted prior to the magnetic particle inspection. If the OTR assembly passes the criteria, the assemblies are shipped back to site. If they fail, they are either repaired or scrapped. This whole process creates logistical challenges and creates unnecessary costs to the asset owner. On several occasions, OTR assemblies have suffered failures worldwide. To minimize this element of risk, inspections and certifications are considered necessary. This standard describes a new proposed practice for electromagnetic methods for examination of OTR assemblies. This practice addresses the need to detect surface breaking flaws electronically and to have the ability to size accurately any surface breaking cracks found on OTR assemblies faster and more effectively than other methods. For use by manufacturers, users and safety inspectors.
