Process steam generators raise steam by utilising MTHW, HTHW, Electric heating or Thermal fluid as the primary heat source. Output duties vary from 50 to 6000 kW. They can be supplied as stand-alone units or fully packaged plant including all the associated controls and safety devices. Process steam generators are generally manufactured from carbon steel and are designed to PD 5500. In order to achieve an economic design it is desirable to operate the generator with at least a 5°C temperature difference between the heating medium and steam outlet pressure.