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.
ideally
Air or Electrical (230/400 60Hz)
5 - 20 l/m
5 Bar
Super Duplex or a suitable wetted part with history of seawater application

HELP!!
  


  

Johnny H-S BSc(Hons) MInstMC

Engineers like to solve problems. If there are no problems handily available, they will create their own problems.
 

Can they do it in 6Mo - UNS S31254 or similar?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04
 

No steve unfortunately the two offers so far are duplex 2207 & 907L as "standard" - not offering to do a run for 2 off.
6 MO is the sample system standard so good shout for that material but not avail.
It seems to be the small duty and the special materials. The lower duty grundfos pump is perfect but only 316. as far as i can see a relatively low duty borehole pump with special materials for seawater cant be got!! (high duty yes but this is for sampling!!)

Johnny H-S BSc(Hons) MInstMC

Engineers like to solve problems. If there are no problems handily available, they will create their own problems.
 

I assume you checked companies like KSB and ITT Flygt already?

How about on a VSD to reduce the pump output.

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Plymouth Tube

Framo makes lots of submerged pumps for installation in pipes or caissons for seawater pumps, for ships and fixed installations, for bilge, cooling, firewater - you name it. I only have good experience with these guys.

www.framo.no

Best regrads

Morten