Chemical valves material choice.


Chemical valves material choice.
Sulfuric acid


As one of strong corrosive medium, sulfuric acid is an important industrial raw material is very versatile.

Corrosion of different concentration and temperature of sulfuric acid on the material difference is bigger,

 the concentration is above 80%, the temperature is less than 80 ℃ concentrated sulfuric acid, carbon steel and cast iron has good corrosion resistance, 

but it is not suitable for high-speed flow of sulfuric acid, is not used as a pump valve materials;Ordinary stainless steel such as 304 (0 cr18ni9), 304 (0 cr18ni12mo2ti) also limited use for sulphuric acid medium.

So transport of sulfuric acid pump valve usually adopts the high silicon cast iron (casting and machining is difficult), high alloy stainless steel alloy (20) manufacturing.
Fluorine plastic has good acid resistance, using fluorine-butterfly valves is a more economical choice.


Hydrochloric acid


Most don't hydrochloric acid corrosion resistant metal materials (including all kinds of stainless steel materials), also can only be used for high silicon molybdenum 50 ℃ and below 30% hydrochloric acid.
And metal materials contrary, the vast majority of non-metallic materials of hydrochloric acid have good corrosion resistance, so the lining rubber and plastic valve (such as polypropylene, fluorine plastic, etc.) is the best choice of transportation hydrochloride.


Acetic acid


It is one of the strongest material corrosion in organic acids, ordinary steel in all concentration and temperature of severe corrosion of acetic acid, acetic acid proof material is stainless steel, 316 stainless steel containing molybdenum can also apply to high temperature and dilute acetic acid steam.
For high temperature and high concentration of acetic acid or contain other corrosive medium such as strict requirements, can choose high alloy stainless steel valves or fluorine plastic valves.


Nitric acid


General metal corrosion and damage, mostly in nitric acid was quickly is the most widely used nitric acid resistant stainless steel material, all to room temperature the concentration of nitric acid have good corrosion resistance, it is important to note that the molybdenum stainless steel (e.g., 316, 316 l) of nitric acid corrosion resistance not only no better than ordinary stainless steel (e.g., 304, 321), sometimes even less.For the high-temperature nitric acid, usually with titanium and titanium alloy materials.


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