The container medium is anhydrous HF. What are the requirements for the on-site environment?

HF is extremely corrosive. I don’t know what materials your manufacturer uses. Generally, carbon steel can be used for anhydrous HF, but graphite and PTFE can only be used when it turns into hydrofluoric acid when it encounters water. Found some corrosion on material matching: Hope it helps you check: Carbon steel is widely used in more than 60~70% hydrofluoric acid and anhydrous HF. The temperature should not exceed 65 degrees. Unaerated acids are less corrosive. Be especially careful when using it at the concentration boundary (60~65%). Dilute acid is very corrosive. According to the test results: The corrosion rate of carbon steel in 93% acid (20 degrees) is 0.9mm/year, and in 48% acid, the corrosion rate is 13mm/year. Mild steel has the best corrosion resistance. Some tanks can last for more than 10 years. All types of stainless steel are not suitable for hydrofluoric acid of any concentration, even at room temperature, because hydrofluoric acid can destroy the protective film on the surface of stainless steel. With one exception, stainless steel can be used for anhydrous hydrogen fluoride at room temperature. Generally stainless steel is not used to handle fluoride solutions. If dilute hydrofluoric acid contains nitric acid or other strong oxidants, it can reduce the corrosion of stainless steel. High-alloy stainless steel has good corrosion resistance to aerated hydrofluoric acid, and is also suitable for dry anhydrous hydrogen fluoride. But be careful when using acid below 60%. Some factories use this material to make pumps. Valves, nozzles, etc. However, it is not economical to use this lining material. This high alloy equipment is only used in special cases, such as mixed liquids containing hydrofluoric acid and nitric acid and crude phosphoric acid containing hydrogen fluoride. 80% hydrofluoric acid reacts at 80-120 degrees, only nickel-copper alloy is suitable for you 1. Carbon steel: Since the interaction between AHF and carbon steel can form an iron fluoride film on its surface to prevent further corrosion, carbon steel is generally suitable for liquid or gas phase AHF below 100°C. When the temperature exceeds 100°C, the corrosion rate increases rapidly as the temperature increases. In order to prevent the surface protective layer of ferric fluoride from being damaged, the linear velocity of the liquid phase AHF flow in the pipeline must be limited. Usually it should not exceed 1m/s at room temperature, and at higher temperatures, the line speed requirements are lower. This restriction also applies to other metals in contact with AHF. For HF aqueous solution (hydrofluoric acid), the corrosion rate decreases as the concentration increases. A certain degree of corrosion will occur when the HF concentration is 85% ； When the concentration is 75%, the annual corrosion rate is 0.5mm ； When the concentration is 65%, the annual corrosion rate is 1.5mm. Therefore, carbon steel is not recommended when the HF concentration is below 70%. Hydrofluoric acid below 60% can corrode steel rapidly even at low temperatures. Even if the concentration of hydrofluoric acid or AHF is greater than 85%, if the lattice defects and stress of the steel are not eliminated, atomic hydrogen may migrate to the inner layer of the steel plate, causing "bubbles". Therefore, when manufacturing equipment such as HF storage tanks, it is recommended to use vacuum-smelted, desulfurized steel (sulfur content less than 0. 01%), and conduct strict ultrasonic flaw detection to ensure that there is no "sandwich" phenomenon. Steels with a hardness greater than 225HB (Brinnell hardness) are prone to stress corrosion cracking in AHF after welding, especially when AHF contains arsenic compounds. 2. Cast iron The corrosion resistance of ordinary cast iron to HF is far inferior to that of carbon steel and cast steel, so parts in contact with HF should not be used. 3. The corrosion resistance of stainless steel austenitic nickel-chromium steel to AHF is no better than that of carbon steel, and it cannot be used at higher temperatures. Hydrofluoric acid at concentrations less than 10% is moderately corrosive to austenitic steel (type 316) at room temperature. High-alloy austenitic steels (such as Carpenter20 and Durimet20) are better, while Monel and Hastelloy C have better corrosion resistance. When selecting No. 20 alloy pipes, it is recommended to choose seamless pipes instead of welded pipes. Austenitic steel can produce stress cracks in dilute hydrofluoric acid at temperatures above 100°C. The presence of fluoride ions may promote the formation of stress corrosion cracks even at lower temperatures, especially in 304 stainless steel. This phenomenon is particularly serious if sufficient stress relief is not performed. Stainless steels should be chosen with low carbon content and varieties stabilized with titanium or niobium. 4. Nickel, Monel and Inconel alloy Monel has good corrosion resistance to hydrofluoric acid with a concentration higher than 50% at room temperature. In order to prevent damage to the passivation layer, it is also required to limit the flow rate and agitation of the material. For anhydrous to 50% hydrofluoric acid, a certain degree of corrosion will occur when the temperature reaches above 80°C. Cold formed or welded Monel products will develop stress corrosion cracking if there is no effective stress relief. When welding, do not use Monel 60 electrode, otherwise the weld will be corroded by HF. The presence of oxidizing agents and reducing sulfur compounds increases the corrosion rate of all these materials. Nickel, Incon alloy and copper-nickel alloy containing 30% nickel have worse corrosion resistance to hydrofluoric acid than Monel. Nickel, Monel and Incon alloys have good corrosion resistance to gas phase HF above 600°C, even in the presence of trace amounts of water vapor. 5. Copper and bronze (Bronze) Copper can be used in hydrofluoric acid with a concentration of 60 to 90% at room temperature. Moderate corrosion will occur when it reaches the boiling point. Bronze also has acceptable corrosion resistance at room temperature and is sometimes used to make hydrofluoric acid pump body components, but is not suitable for higher temperatures. 6. Hydrofluoric acid in all concentrations of titanium and tantalum will cause strong corrosion to these two metals. HF is also very toxic. In the past, titanium container manufacturers used it to make pickling formulas, but now they are afraid to use it. When HF comes into contact with the skin, it will dissolve with the body's water and form hydrofluoric acid. It can penetrate the human skin and react with bones, so it will not react when exposed to HF. When you feel pain then or later, the best solution is to rinse with plenty of water for at least 30 minutes, and then seek medical attention immediately. The poster is from HZSEI, right? There are quite a few F chemical companies in Zhejiang, so you are unlucky if you have to pay for regular inspections. You must strictly abide by all safety regulations during regular inspections, as the accident rate is high.