A cleaning product is discussed which protects metals as it removes rust from corroded surfaces. This bi-fimctionality and the slow rate of removal makes it a candidate for on-line cleaning of HVAC loops. Two different mechanisms are involved in silt and rust removal. Silt is dispersed, while hydrated rust is di~persed as well as solubilized. Air-dried iron oxide attached to a corroded field pipe did not disperse but was slowly
solubilized. Corrosion inhibition afforded by the formulation is studied gravimetrically and by LCM. It showed mild steel protection in presence of the product is not limited to clean surfaces, but is extended to under-deposit corrosion.