Boilers with a wide range of capacities are used within the process industries. In
most oil refineries and large petrochemical plants, the individual boilers have capacities
between 100,000 lb/h and 1 million lb/h. However in other sectors, such as specialty
chemicals and food and beverages, boiler sizes down to 10,000 lb/h and less are
common. Typical utility boilers, in contrast, produce in excess of 3 million lb/h of steam.