Processes for coating the interior surfaces of tanks

Claim 1

THE PROCESS OF FORMING A CONTINUOUS LEAKPROOF COATING ON THE BOTTOM AND SIDEWALLS OF A METAL TANK HAVING A TOP CLOSURE PROVIDED WITH AN INLET OPENING; AND THE TANK BOTTOM HAVING A DRAIN OPENING: COMPRISING THE STEPS OF PUMPING INTO THE FRAIN OPENING A COATING LIQUID COMPOSED OF AN ORGANIC RESIN DISSOLVED IN A VOLATILE SOLVENT UNTIL THE BOTTOM AND SIDE WALLS ARE COVERED WITH THE COATING LIQUID; PUMPING OUT THROUGH THE DRAIN OPENING THE RESIDUE OF THE COATING LIQUID AT A RATE FASE ENOUGH TO LEAVE AN ADHERENT COATING OF THE DESIRED THICKNESS WHILE SIMULTANEOUSLY WITHDRAWING THROUGH THE INLET OPENING THE VOLATILE VAPORS ARISING FROM THE LIQUID COATING AT A RATEE SUFFICIENT TO REDUCE THE PRESSURE IN THE TANK BELOW ATMOSPHERIC PRESSURE AND PROMOTE EVAPORATION OF THE VOLATILE SOLVENT FROM THE COATING ON THE SIDEWALLS; AND SUBSEQUENTLY PASSING AIR INTO THE DRAIN OPENING AND OUT THROUGH THE INLET OPENING TO REMOVE ANY RESIDUE SOLVENT VAPORS FROM THE TANK.