Abstract: A portable tank spray cleaning apparatus is comprised of a manhole sealing component and a spinner spray component. The manhole sealing component is adapted for use in the manhole of a storage tank during a cleaning operation to seal the interior thereof. The sealing component comprises a cylindrical-shaped core with a base plate which fits into the manhole and a cover plate which rests on a lip of the manhole. An inflatable tube is positioned on the core. A connecting tube extends through the base plate with one end used for connection to a cleaning solution delivery hose and the other end used for connection to the spinner spray component. A vent pipe optionally also extends through the base plate to relieve a pressure build-up during a cleaning operation. In operation, the tube is pressurized to inflate it and create a seal against the sidewalls of the manhole.