Material issues of various components in magnetic pump

You have way too many questions; do you think that’s a sign of eagerness to learn?

The last edit to this post was made by 3983596_FPPZ on 2019-3-20 at 09:32. It’s really good that those who are eager to learn don’t just ask questions as soon as they encounter problems; instead, they try to find answers on their own by searching for information. Only when they can’t find the desired answer through research and still can’t figure it out do they seek help and discuss it with others

1. What model series is the magnetic pump you’re seeing? It’s a non-metallic magnetic pump, right? Such pumps are used for highly corrosive media. Using silicon carbide for the shaft does indeed result in weaker strength; the shaft is fragile, so it’s only suitable for small-scale applications with highly corrosive conditions and stable operating conditions. Magnetic pumps with metal isolation sleeves and metal shafts are the most common type.
2. Magnetic materials such as Y33BH (ferrite), Nd2Fe14B (neodymium-iron-boron), and samarium-cobalt all belong to the category of magnetic materials that have been developed over time. Like cemented carbides, they are part of the powder metallurgy family. Among these, ferrite has the lowest magnetic strength, neodymium-iron-boron has the highest, while samarium-cobalt materials offer the best temperature resistance. Each of them has its own characteristics and applications.
3. The use of samarium-cobalt for the internal magnets and neodymium-iron-boron for the external magnets is something I’ve heard of for the first time. This seems to be an attempt to reduce costs, but I think it’s not appropriate. Conditions where samarium-cobalt can be used are usually those with high temperatures or where the isolation sleeve generates a lot of heat. Moreover, neodymium-iron-boron magnets are also prone to demagnetization.

Rare earth samarium-cobalt materials can withstand high temperatures, while neodymium-iron-boron materials cannot

Is 120°C considered high temperature? How to choose materials for inner and outer magnets?

Can ferrite still be used? Has it already been eliminated?

They have been phased out; some of the earlier magnetic pumps are still useful, as they are used in other industries. Since they do not contain rare earth elements, their cost is low

It seems that the poster is looking to choose a fluorinated magnetic pump; the manufacturer will make recommendations based on the medium and operating conditions. There’s no need to worry about the strength of the shaft material – such pumps are widely used, so you certainly won’t be treated like lab rats! The material of the magnet is chosen because fluoropolymer-lined pumps do not operate at high temperatures; neodymium-iron-boron magnets can handle 120 degrees without issue. Samarium-cobalt magnets are more expensive, and in addition to operating at higher temperatures, they also have a lower magnetic induction strength. The shielding cover in these pumps is non-metallic, which means there is no magnetic loss, so it is not the preferred choice for fluoropolymer-lined pumps! It’s beneficial to choose a higher torque coefficient for the magnetic cylinder; I hope this helps you.

After all, users are not those who manufacture pumps, so there’s no need to focus too much on material issues. Just look at the technical specifications of the pump and the selection data recommended by the pump manufacturer.