The use of assembled modular machinery
The manhole is used for service personnel access inside the tank, including for tank cleaning.Typical manhole dimension in accordance with the Technical Inquiries for API Standard 650, Welded Tanks for Oil Storage (The API 650 tanks are usually found in refineries, pipelines, terminals, and process facilities.):Compact or assembled modular machinery for mechanical cleaning is required.A powerful, and therefore large and heavy, washing system can only get into an oil storage tank in parts through the narrow manhole.