As the nation’s generating fleet continues to age and become outdated, facility operators are looking for a better way to gain efficiencies and maximize output. This typically revolves around new controls methods, valves, pumps and turbine upgrades. However, a frequently overlooked element within these plants may pose a greater risk if not addressed: piping support systems and engineered supports. These critical parts, if past their operational life, may place your plant and personnel in a high stress and dangerous situation.

Be Aware of Your Piping System’s Stress Level

While guidelines do exist for the inspection, testing and maintenance of designed and installed plant piping systems — per code ASME B31.1 — not all systems may require examination and evaluation. High energy piping (HEP), however, should have a minimum inspection duration to closely watch wall thickness and generation condition. This becomes even more necessary if the system has been prone or subjected to steam hammer, slugging or higher-than-designed operating temperatures, which could cause an overstressed condition. The issue arises in the code’s language; there is a lack of coverage regarding the evaluation of the engineered hangers and supports that help to limit and control those stresses within the HEP.

Engineered hangers and supports endure many hot and cold cycles during their lifespan, causing springs to yield and components to crack, plus a general reduction in strength. Combine the reduction of support with thinning minimum wall thickness, steam or water hammer, and slugging, and a pipe can become overstressed enough to create a system failure. Regular hammering of piping, HEP or balance of plants can accelerate the potential failure mode by further damaging the piping or deteriorating the support capabilities. A failure of either of these components would not only damage the offending pipe or hanger, but also any equipment and structures nearby — resulting in significant capital repair costs.

Consider the Benefits of a Monitor Program

To avoid this failure risk, facility operators are recommended to evaluate and review the plant piping support systems routinely during every major outage. Any spring in hanger locations during normal unit operations and during shutdowns should also be recorded and logged to indicate possible early failure risks or yielding of the components. This simple task could help prevent unit downtime, personnel injury or equipment damage.

When compared to the purchase and installation of a new pump or electrical component, investing in a program to monitor and evaluate engineered hangers is relatively inexpensive. To properly evaluate such a system, facility operators need a piping isometric and the proper software, such as AutoPIPE® or CAESAR II®, to calculate stresses within the pipe based on support types and their current positions. By understanding the loads encountered and partnering with a piping support manufacturer, you can set up your plant to run longer and safer.

Our team has extensive knowledge and experience designing and supporting HEP systems to avoid these unseen stresses for our clients. Contact us to learn more about HEP inspection programs for your plant.

Bryan Durant is a mechanical engineer at Burns & McDonnell with more than 17 years of experience designing power plants. As the plant improvements mechanical business unit manager, he’s responsible for the identification, development and execution of small operations and maintenance and capital projects.