The material of chemical industry pneumatic valve how to choose, 1)

. Nitrate general metal corrosion and damage, mostly in nitric acid was quickly & lt; 。 Most general metal nitrate was rapidly in nitric acid corrosion damage. Stainless steel is the most widely used of nitric acid resistant material, all to room temperature concentration of nitric acid have good corrosion resistance, in particular the molybdenum stainless steel ( If L nitric acid corrosion resistance not only no better than ordinary stainless steel ( If sometimes even less. For the high-temperature nitric acid, usually with titanium and titanium alloy materials.
corrosion is one of the dangers of chemical equipment the most headaches, for a long time. Light damage to the equipment, or caused by accidents and even cause disaster. According to statistics, chemical equipment about % damage caused by corrosion in chemical pneumatic control valve selection should first pay attention to the science of material selection. For some commonly used chemical media talk about the main points of the selection below:

. 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 in the % above, temperature less than ℃ concentrated sulfuric acid, carbon steel and cast iron has good corrosion resistance, but it is not suitable for high-speed flow of sulfuric acid, & lt; 。 One of the strong sulfuric acid as a corrosive medium. Is not used as a pump pneumatic valve data; Ordinary stainless steel such as CrNiCrNiMoTi also limited use for sulphuric acid medium. So transport of sulfuric acid pump pneumatic valve usually use high silicon cast iron ( Casting and machining is difficult) High alloy stainless steel ( Alloy) Manufacturing. Fluorine plastic has good acid resistance, the use of rubber fluorine pneumatic valve is a kind of more economical choice.

organic acid in the acetic acid corrosion, one of the strongest material & lt; One of the strongest material organic acid in the acetic acid corrosion. Ordinary steel in all concentration and temperature of severe corrosion of acetic acid, acetic acid proof material is stainless steel, 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 pneumatic valves or fluorine plastic air valve.

。 Hydrochloric acid most metal materials are not resistant to corrosion, Including all kinds of stainless steel materials) High molybdenum silicon also can only be used for ℃, % the following hydrochloric acid. And metal materials contrary, & lt; 。 Hydrochloric acid most metal materials are not resistant to corrosion, Including all kinds of stainless steel materials) High molybdenum silicon also can only be used for ℃, % the following hydrochloric acid. And metal materials contrary. The vast majority of non-metallic materials of hydrochloric acid have good corrosion resistance, so the lining rubber pneumatic valves and plastic air valve ( Such as polypropylene, fluorine plastic, etc. ) The best choice of transportation hydrochloride.