Steam is used in many different applications and processes. In most of these cases what is called ‘plant’ is used, which is fit for purpose and very effective. In some cases however steam has to be of a higher purity level. This is generally labelled as ‘clean’ steam. In fact there are different levels of clean steam depending on the application requirements.
This is the most common steam found in industrial applications, including for example heating processes. There are no controls over chemicals and condensate quality within the steam. The plant steam chemical treatment is tailored to suit boiler operation and pipework.
Filtered steam is a filtered form of plant steam. It is used in applications where control is required over organisms and particles in the steam. Generally a sintered element filter is installed in the steam pipework upstream of the application. The steam filters allow for filtering out all particles down to 1micron in size. There is no control on condensate standards after the filter. The only concern is particle size. This would generally provide a good quality of steam for use in industrial and in some cases food applications.
Clean steam is used when chemical contamination is unacceptable, particularly used within sterilising and fine chemical manufacture. Clean steam is raised from a reverse osmosis or demineralised water supply. The clean steam generator and all associated pipework and equipment must be in stainless steel grade 316L.
The highest level of steam purity, pure steam has defined levels for chemical contaminants as well as levels for bacterial endotoxins (pyrogens). These defined levels permit the steam to be used for the production of chemicals which can be used in direct injections into the human body.