Hello lovely Engineering Community!
I have an issue regarding a pump that is required for an offshore application (north sea). I'll try and give all the info but keeping it brief to still keep your interest!!
Basically it is for supplying sample (5 litres a min required at 5 bar head) to monitor oil in seawater (ambient). (oil at the low ppm level)
The seawater is for discharging back into the sea after analysis from a tank.
The end user has specified Super Duplex. (grade 2507 ss) unfortunately i have searched 14+ suppliers and cannot find any that will do this application exactly!
The closest i have come is a SS duplex 2207 air driven pump which provides the right duty (ATEX also which is handy) but not material wise. Duplex is not pref by the end user as
"Metallurgy had already advised us that Super Duplex is required for this seawater service and from our own browsing it appears that they are entirely correct in this – with pump manufacturers' own websites confirming that pitting corrosion is a significant problem with Duplex pumps in seawater service, the corrosion performance being significantly improved with the use of Super Duplex"
The next closest is a 904LSS Grundfos pump which is used offshore - lovely and would be suitable for the seawater BUT the lowest duty i can get is 115L/M - well over the top and might well empty the tank to provide a sample!! Again, not a pref! The lower duty pumps are only avail in SS316 with sacrificial anodes but wouldnt be a pref i think!
So i'm looking for any ideas for suppliers from you guys and suggestions for this application.
Air or Electrical (230/400 60Hz)
5 - 20 l/m
Super Duplex or a suitable wetted part with history of seawater application
Johnny H-S BSc(Hons) MInstMC
Engineers like to solve problems. If there are no problems handily available, they will create their own problems.