This Technical Information Paper (TIP) pro- vides guidelines and procedures for the inspection of batch digesters. It addresses inspection frequency, planning, methods, locations, cleaning and preparation, personnel qualifications, test equipment and documentation of findings.
This TIP does not discuss the interpretation of inspection data. These guidelines are not intended to supersede jurisdictional and regulatory requirements.
This TIP addresses inspection of batch digester vessels and their welded attachments. It does not address associated piping, auxiliary systems or protective devices.
The primary focus of this TIP is welded carbon steel digesters that are stationary and vertical. These may be internally protected with stainless steel or high alloy weld overlay, thermal spray coatings or brick linings. Some digesters are constructed of composite plate. Guidelines for other types of digester construction like solid stainless steel, riveted, rotary or spherical, are not specifically addressed.
