The main components of the red spot is iron oxides (Fe2O3, Fe3O4),It may also contain iron ,chromium,nickel and other trace elements.Although it is found the red spot in water, it is more common in heat WFI machine,pure steam generator and pipeline .The typical location of the red spot include:heat exchanger(especially at the hot end ),pump shell and pusher, atomizer and spray area of water for injection tank ,diaphragm of valve etc.Although it’s red by name ,the “red spot “found also has other colors ,sometimes darkening as the temperature rises .In the pure steam generator ,this material may also be gray or black .In the early stage, “red spot” is a loose pieces of powder ,which can be easily wiped off .

Install 0.2 us/cm or 0.45us/cm filter at sampling point ,and the loose “red spot “particles will be detected after several hours .Finally,”red spot “becomes and attachment to the surface ,or smooth induration,which can’t be removed by wiping .When the stainless steel can be covered with “red spot “,its shape becomes relatively stable,and no more the red spot is generated or dispersed into the system . This can be proved by filtration test . Therefore ,in the pure steam system ,the filter should be installed for the red spot part .