I have a 1955 Probal L12 which is running on natural gas. I''m thinking of moving my roasting facility where the only option for gas is LPG. I''ve read some of the posts, and most focus on the safety. That aside, does anyone know how much LPG a machine like mine uses? (eg., per hour of roasting) I''m trying to estimate how may little tanks I''ll go through or if the only reasonable choice is to use a large tank (which may not be practical here) I don''t want to find myself switching tanks every hour, or loosing a batch because I couldn''t change it fast enough. Thanks, John.