Replacing a fiberglass header with a steel header for a Chilled Water System


As a result of a failure in a fiberglass header in the undercroft of a chilled water system, the decision was made to replace the damaged header with a steel one. This alteration in material had a significant impact on the static and dynamic characteristics of the entire chilled water system. Engineers at Dynaflow Research Group were tasked with assessing whether further adjustments were necessary to accommodate the changes brought about by the installation of the steel header. Within the system, multiple valves were positioned across the two headers to regulate flow, depending on the operational status of the York chillers.


An in-depth analysis was conducted on the system to evaluate its static and dynamic behavior. The static analysis aimed to ascertain the stresses and loads induced by factors such as temperature, pressure, and the weight of the water and pipe. Meanwhile, the dynamic behavior of the system was scrutinized to incorporate additional forces stemming from the activation and deactivation of various pumps within the system.

During the dynamic analysis, careful attention was paid to ensuring that the maximum and minimum pressures within the system remained within acceptable limits as per stress and surge analysis standards. Particular emphasis was placed on assessing the integrity of the fiberglass component during both static and dynamic analyses.

“Static and dynamic analysis are performed to determine the stresses and loads due to temperature,
pressure and weight.”


The recommendations presented were the culmination of a comprehensive evaluation of the system’s static and dynamic aspects. A proposed support arrangement for the new steel header was among the primary suggestions. Additionally, specific recommendations regarding the type and quality of support were outlined. Fortunately, no extensive rerouting of components was deemed necessary. Upon implementation of the recommendations, the system operated in accordance with the specified requirements.

Share this article

Related Articles