Regarding the corrosion issue associated with whether acids are pressurized or not, and how to select the material for pumps used to transport acids
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In the corrosion manual, the corrosion data for most acids are categorized as either with gas atmosphere or without gas atmosphere. What exactly does this mean by \"with gas atmosphere\" and \"without gas atmosphere\"? Is it the continuous addition of air or other gases to the acid, or are it bubbles formed at low pressure by gases dissolved in the acid itself (such as hydrochloric acid or hydrofluoric acid)? If selecting a material for an acid transfer pump, what does it have to do with whether inflation is used or not?
If there are gases in the acid, cavitation will occur, damaging the pump chamber and impeller. There are many materials that can be used for acid media, both metallic and non-metallic ones, depending on the specific type of acid involved.
So what exactly does it mean by inflated and not inflated?
It can be simply understood in this way: inflation means that the material is in contact with air, in an open container or pipeline, under aerobic conditions. No inflation; the container is full of material, or the gas phase inside is the saturated vapor of the material, creating an oxygen-free environment. When selecting the material for the pump, it is not necessary to consider whether inflation is present or not, as pump manufacturers generally choose materials based on corrosion under aerobic conditions; otherwise, the pump would not be able to stop operating.