Cast Iron, Potable Fresh Water Pump Body
Can you recommend a process to clean rust and “cure” the interior of a pump housing to prevent rusting and not affect the quality of the water?
Q. The inside of a pump is rusting to the point that small rusted parts flake off. Can you recommend a process to clean rust and “cure” the interior of the pump housing to prevent rusting and not affect the quality of the water? C.W.
A. Cast irons can be “active” and rust rather quickly. If the level of rust is moderate, and it does not sound like it is very adherent, a phosphoric acid cleaner may be ideal to clean and remove the rust residue. Additionally, phosphoric acid cleaners are unique in that they can leave a deposit that is similar to that of a very simple, lightweight phosphate coating on the surface which can provide the “cure” or passive surface you are looking for. Increasing time and temperature (if possible) will accelerate the process and/or do a better job removing existing rust.
The German Association of the Automotive Industry’s VDA Volume 19 is the first comprehensive standardization document for characterizing the cleanliness of products within the automotive industry’s quality chain.
How to use it for planning, preventive maintenance and troubleshooting.
A more realistic way to perform salt spray tests.