During refueling outages, Reactor Pressure Vessel (RPV) cavity flooding can unnecessarily increase maintenance time and exposure. Preferred Engineering’s Stud Hole Plug Set provides a proven solution, sealing stud holes to prevent water intrusion – preserving critical flange components and eliminating the need to clean flooded threads.

Engineered specifically to prevent cavity water from contaminating the threaded holes, the Stud Hole Plugs are designed to rest on the uppermost thread and seal against the counterbore walls, creating a secure barrier without compromising the threads. Because the anodized aluminum IR tools are able to pass through the RPV flange, installation can occur with the RPV head in place.

The body of each plug is machined from ultra-high molecular weight (UHMW) plastic, offering excellent durability while protecting machined threads and sealing surfaces. The Ethylene Propylene Diene Monomer (EPDM) Rubber Seal provides reliable performance in wet, high-radiation environments.

Visit the Stud Hole Plug Set page on our website for more information on this product.