Hello, Herb here. I’d like to explain about pneumatic mechanisms on your Westinghouse high voltage circuit breakers and the need for an upgrade replacement kit. The earlier vintages of pneumatic mechanisms AA7, AA10, & AA14 were fitted with Dresser type fittings on the air piping between the air reservoir and breaker control valve. These fittings were made up of an elastomer seal, stainless steel cup and cast iron nut. Over time the elastomer seal begins to deteriorate and/or shrink, requiring maintenance personnel to tighten the nut to temporarily fix the leak. Eventually the elastomer needs to be replaced. To eliminate these seals, Westinghouse developed a replacement kit with a flexible hose and threaded connections. The globe valve was also replaced with a ball valve since the globe valve and parts for the globe valve are no longer produced. The picture on the right is the replacement kit for the AA10. Kits for the AA7 & AA14 are also available.
|Upgrade replacement kit|