Design of the pump used to transport nitric acid

Fluorinated magnetic pumps can be used; they are resistant to nitric acid corrosion and can also ensure no leaks!

The key factor in determining which pump is more suitable – a shielded pump or a diaphragm pump – is the flow rate. Magnetic pumps can fully meet the requirements; however, there is no need to use fluorinated magnetic pumps. Nitric acid (of high purity) can oxidize ordinary stainless steel, but such pumps should still be resistant to corrosion. Our company uses simple centrifugal pumps equipped with mechanical seals, and these are also sufficient to meet the requirements

It is considered better to use a magnetic pump with a fluorine-lined interior, as that is more reliable.

Nitric acid is a strong oxidizing agent, and dilute nitric acid also possesses strong oxidizing properties. Stainless steel has good corrosion resistance due to its tendency to form a passive layer in dilute nitric acid. It can be said that almost all stainless steels exhibit fairly good corrosion resistance in dilute nitric acid. Type 18-8 Cr-Ni austenitic stainless steel possesses excellent resistance to dilute nitric acid, as well as good comprehensive properties in terms of mechanics, formability, and weldability. Therefore, it is widely used in dilute nitric acid with a concentration of less than 65%. However, as the concentration of dilute nitric acid increases, especially when it exceeds the azeotropic concentration of 68.4%, type 18-8 steel generally can no longer meet the requirements. Even at higher concentrations, due to the peroxidation effect of nitric acid and the self-passivation of chromium-only stainless steel, 18-8 steel will suffer severe corrosion. Therefore, at this time, a Cr-Ni stainless steel with a Si content of ~4% needs to be selected. For example, commonly used grades such as C4 (00Cr14Ni14Si4) and C6 (00Cr20Ni24Si4Ti) are often used in concentrated nitric acid and fuming nitric acid at temperatures not exceeding 80 degrees Celsius. At even higher temperatures, a stainless steel with a Si content of around 6% is required, such as 00Cr17Ni17Si6. So, regarding the reply from the third floor above, I am personally puzzled. However, I’m not sure what the poster means by high-purity nitric acid – does it refer to the concentration? Does it still mean it contains no other impurities? I personally also think that it is safer to choose a magnetic pump made of fluoroplastic. Also, please have the original poster take a look at these two links: http://www.jxcad.com.cn/read.php?tid=106228 and http://bbs.hcbbs.com/viewthread.php?tid=310323&extra=page%3D1&frombbs=1. This post was last edited by *eqiguo on 2008-11-5 at 11:50.]

The magnetic pumps chosen by our company were used to handle liquids with a concentration of 98%; they became corroded after less than a month of use. Several replacement pumps, even imported ones, didn’t work either, so in the end we opted for centrifugal pumps.

What is the material of the 6L pump body?

Does anyone know anything about this C8 material? I’d like to learn some information about it.