Engineered FRP vessels are highly tailored products. That means that the particular resins, initiators and reinforcement fabrics used to fabricate these vessels were chosen specifically from dozens of choices, with one goal in mind; to provide the customer a vessel with the best performance and durability.
Diamond uses the information provided by the customer to select materials and fabrication methods, and if the information is incorrect or incomplete, then it is possible an FRP vessel may be subjected to a condition that wasn’t anticipated, and the asset may not meet the goal of best performance and durability. Despite our extensive experience and best efforts to ask all relevant questions, sometimes vessels are used for different purposes once the vessel has left our factory and is “out in the wild”.
Storage Vessel used as Reaction Vessel
Sometimes specifications will state that a tank is intended to be a “storage vessel” for a particular substance. But the specifications don’t clarify that one substance is mixed with one or more different substances in the tank. The result could be a dilution of concentration, or a chemical reaction, neither of which was anticipated when the materials of fabrication were chosen. These reactions may result in a vessel exceeding its design conditions (such as temperature or pressure).
Atmospheric Vessel used as Pressure Vessel
Another issue that arises from time to time is a vessel rated for atmospheric service but at some point it is converted to a closed system that pressurizes the vessel. An example is when an owner re-routes the vent to a scrubber system which can create vacuum or back pressure on the vessel. Some standards such as ASME RTP-1 try to prevent this scenario by requiring atmospheric tanks to use fixed non-removable vents.
Operating conditions never anticipated
“Off spec moments” can also introduce conditions that are not anticipated in the original specifications. Such moments can be the result of an annual cleaning, human error or equipment malfunction. Other scenarios occur when owners “repurpose” vessels for different services than they were designed.
While the off spec moments may never be able to be anticipated, operating outside of the original specification design or repurposing a used vessel can be checked for acceptability by reaching out to the original vessel fabricator for guidance.
For more information, visit diamondfiberglass.com or diamondservices.com.
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