Because a ProSonix direct steam heater adds condensed steam to the fluid used in a food process, many wonder if there are restrictions on the type or quality of the steam used to heat the fluid. There are, and the restrictions will vary depending on the process.
Steam used to heat water for general cleanup generally has no restrictions because there is no food contact.
Steam used for heating fluids in direct contact with food will generally require the boiler treatment chemicals to be limited to those safe for human consumption. The chemicals are greatly diluted in the final heated fluid so the contamination risk is generally low, but care should be taken in which boiler treatment chemicals are used. In addition, the steam will likely need to be filtered to remove any solid particles that could impact taste or appearance and the steam piping downstream of the filter will need to be stainless steel.
Some processes in the dairy or pharmaceutical industries have higher requirements for direct steam injection. These requirements are covered under standards such as 3A 61-02 or ASME BPE-2022. These standards detail the specific requirements for steam to be injected into the processes.