Introduction
The Parker MPW motor is built specifically for environments that require frequent washdowns typically using high pressure water using austenitic stainless steel. Some of the more common industries that use this motor family are food and beverage, pharmaceutical, and packaging applications. However, other locations have found uses including chemical plants, factories located in a coastal region, and even aboard ships.
Parker selected stainless material for the housing specifically to prevent the effects of corrosion brought about by water and other chemicals used in the cleaning process. Stainless will have a significantly longer life than standard carbon steel and is suitable for corrosion-prone environments; however, it is not impervious to its effects.
Corrosion
Common corrosion that occurs on stainless material includes 1.) pitting which is caused by free-floating ions (chlorides are among the most common) and 2.) crevice corrosion which occurs in low-oxygen areas like crevices. Salt-rich environments (especially coastal regions) require extra precaution since they are most likely to cause the common forms of corrosion.
Example of pitting corrosion
Corrosion will “eat” at the surface. Over an extended period of exposure the corrosion could potentially compromise the housing thereby allowing salts to enter and further degrade the internals.
Prevention
The severity and rate of exposure will depend on many factors, but the onset of corrosion will generally be slow. Thankfully, there are steps one can take to prolong the life of the MPW’s stainless housing.
- Pitting can be prevented by routinely washing the surface of the motor. Spraying the housing such that the contaminants don’t stay on too long will help prevent pitting from setting in.
- Sealing any cervices with some flexible sealer like rubber or silicon will help in the prevention of crevice corrosion.
- Passivation is a process that builds up a passive sacrificial layer via an acid application. We do not passivate the MPW housing as standard since a rust inhibitor is used during fabrication and the surface finish is electropolished. The electropolished finish greatly enhances the prevention of corrosion by making it difficult for corrosive particles to rest on the surface.
Other resources
The following links direct you to other articles and documents that discuss stainless material, corrosion, and corrosion terminology.
