Shutterstock
engineer work service checking and maintaining industry boiler

Can Your Equipment Handle Operational Changes? What to Know About Uprating and Rerating

June 3, 2025
As production demands shift, so must your equipment. Learn how to evaluate whether pumps, vessels, piping, and other assets can safely handle higher loads, pressures and temperatures.

Engineers and operators in chemical processing plants are increasingly required to evaluate equipment and machinery for higher loads, greater stresses, elevated operating pressures, increased capacity and other more demanding operational parameters. 

Additionally, they must reassess existing equipment to accommodate new or modified operating conditions. Despite the growing frequency of these rerating and uprating projects, there is a notable scarcity of published reports about the methods. This article outlines a systematic approach engineers can use to assess the reliability, safety and longevity of critical equipment under evolving operational demands.

Uprating for increasing equipment demands is closely related to the maximum operational loads the equipment or machinery can handle before damage, failure or potential malfunction will occur.

This means assessments for new operational cases must account for all possible failures and issues. This is applicable for rotating equipment, fixed equipment, processing packages, bulk material handling systems, such as conveyors, among others. 

The uprating and rerating processes should also involve all equipment components to identify whether they contribute to potential weaknesses and bottlenecks. 

Operational and Mechanical Considerations

When uprating or rerating, the equipment should be strong enough to withstand higher stresses, dynamic loads, shock, twist, vibration and other adverse effects for the intended new operation. Along with strength, another important consideration is to ensure adequate stiffness, such as bending stiffness, exists. The deflections and deformations should still be small under new operational loads. This, along with good dynamic behaviors, mandate high overall stiffness. Corrosion, erosion and temperature changes may need to be considered and properly assessed. 

The mechanical and operational assessment for the uprating and rerating is typically a complicated process with many steps and stages. Usually, many parameters and factors are involved and some of them, such as failure criteria, corrosion rate, fatigue and brittle facture, are often subjected to uncertainties and changes based on operational and environmental conditions. The matters are too complicated and too nonlinear to be calculated or simulated easily and accurately. The overall equipment or machinery should remain fully and reliably functional under new operating cases for the intended life. 

About the Author

Amin Almasi | rotating equipment consultant

AMIN ALMASI is a mechanical consultant based in Sydney, Australia. He specializes in mechanical equipment and offers his insight on a variety of topics including pumps, condition monitoring, reliability, as well as powder and fluid handling and water treatment.

Sponsored Recommendations

Nominations are open for Chemical Processing's biennial awards. Submit your product innovations in one of 10 categories.