oil for seal chambers centrifucal pumps

[ronmonical]

hey i'm trying to get my company to look at the oils where using for the seal chambers on our flygt,homa and ksb pumps, where using a 40wt engine oil now but i think a lighter 20wt oil more suited for wet and buna n rubber is needed. I've gotten recomendations from corn oil tellus-100 to 30wt engine oil. what do you say. by the way i didn't know corn oil came in different weights. the 40wt churnes into a goey mess. do i want a oil that wont mix with water or one that does?

 

[onion]

what are these pumps being used for?

 

[ronmonical]

influent pumps ksb 350/500/1268x got recomendation from ksb to use anyone of these exxon marcol #87, amoco superla white mineral oil #9, conoco pale paraffin oil 10, shell shellflex 210, unocal unax 22, lyondell duoprime oil 90 or any brand vegetable oil. want to use turbine oil cause i got plenty or corn oil cause its easy to get