CEMA Standard No. 502-2022 – Bulk Material Belt Conveyor Trough and Return Idlers

CEMA Standard No. 502-2022, Bulk Material Belt Conveyor Trough and Return Idlers: Selection and Dimensions with Metric Conversion, provides uniform dimensional, mounting, clearance, and load-capacity information for idlers used in bulk material belt conveyor systems.

The standard promotes interchangeability of complete idler assemblies among conveyor equipment manufacturers while allowing manufacturers flexibility in the design and construction of individual components.

The publication addresses:

• Idler nomenclature and CEMA classifications
• CEMA Classes B, C, D, E, F, and G
• Trough idlers with 20°, 35°, and 45° troughing angles
• Flat and V-return idlers
• Picking idlers
• Live-shaft idlers with steel-tube and rubber-disc designs
• Belt-scale idler requirements
• Roll run-out standards
• Idler load ratings and capacity tables
• Idler selection procedures
• Imperial and metric selection examples
• Metric SI conversion factors
• Comparison of CEMA 502 with selected international idler standards

The idler-selection section helps conveyor designers evaluate factors such as belt width, belt speed, material load, idler spacing, bearing life, roll diameter, maintenance conditions, operating environment, temperature, and impact loading.

The 2022 edition includes a comprehensive update to the “Selection of Idlers” section, revised example calculations in imperial and metric units, corrections to trough-idler illustrations, and additional clarification in the comparison with international standards. The publication title was also revised for consistency with industry terminology.

Publication details

• Edition: 2022
• Length: 68 pages
• Includes imperial and metric values
• ISBN: 978-1-891171-92-5

This publication is intended for conveyor engineers, designers, manufacturers, systems integrators, consultants, operators, and others involved in specifying or selecting bulk material belt conveyor idlers.