This technical guide presents a structured process for increasing the maximum allowable working pressure of cast iron, ASME-constructed paper machine dryers without physically modifying the dryer. It covers documentation review, design calculations, ASME data reports, nondestructive examination methods, authorization and jurisdictional requirements, additional inspections and testing, revised pressure stamping, and completion of alteration records. The guide also addresses factors such as thermal loads, centrifugal forces, shell thickness, dryer components, pressure testing considerations, and coordination with authorized repair agencies, inspectors, insurance providers, and local authorities.
Application Scope: Intended for paper mills, dryer engineers, authorized repair agencies, inspectors, insurance representatives, and other qualified professionals evaluating pressure rerating of cast iron paper machine dryers originally certified to the ASME Boiler & Pressure Vessel Code.
