Many people prioritize stainless steel pumps when pumping seawater or saturated salt water. They feel that the stainless steel material is durable and does not require much maintenance, but it is faster to detect damage when used, and the stainless steel pump is severely corroded.

Seawater is a very complex multi-component aqueous solution. The main elements in seawater include Na ions, K ions, CL ions, SO4 ions, etc., and most of these contents are above 1mg.

Various authoritative books have strict requirements for the corrosion of stainless steel in CL ion environments: the content of CL ions should be less than 25ppm, otherwise stress corrosion, pore corrosion, and intergranular corrosion will occur. The content of CL ions in seawater exceeds the requirement for corrosion of stainless steel by over 1mg. Therefore, in general, stainless steel material is not recommended for seawater pumps.

If stainless steel material has been selected, it is recommended to add appropriate corrosion inhibitors or consider replacing with plastic pumps if process conditions permit. Using fluoroplastic pumps to pump seawater not only provides excellent resistance to seawater corrosion but also reduces usage costs.