Causes of slippage of odometer wheels in pipeline inline detectors

Odometer wheels are often used in inline detectors for axial positioning of defects in pipelines. In practical application, "slippage" of odometer wheels may lead to inaccurate positioning due to losses in metering. To enhance the positioning accuracy of pipeline inline detectors, root causes for slippage are analyzed. A moment equation is established for rotation of rolling wheels to identify impacts of parameters on such slippage. In addition, existing rolling friction models are used for verification. Modeling analysis results show that limited accelerating capacities of rolling wheels may lead to slippage of odometer wheel in case of excessive acceleration of detectors, thereby producing inaccurate mileage metered. Incorporation of velocity control system on detectors may effectively regulate running speeds of detectors to eliminate possibility of excessive acceleration. In addition, enhancement in spring rigidity, reduction in diameters and widths of wheels, knurling on external surface of wheel, regional heat processing and other techniques are also available to enhance capacities of odometer wheel to cope with acceleration of detectors.