low shearing pump API 610

[johnthebest]

Hello everyone

I had a clarification from the contractor saying the following:

"This clarification is related to Produced Water Buffer Pumps
As per Process datasheet, given service requires "low shearing pump" and pump mentioned for this service is Centrifugal type.

Please note that for a centrifugal pump to fulfill the ‘low shearing’ requirement, very low speed pumps would be required, however centrifugal pump with low speed would not satisfy the Process condition of 4m3/hr flow and 107m Head. Further, centrifugal pumps due to high speed and centrifugal action, are known to shear oil droplets while pumping the Produced Water.
Hence, centrifugal pumps supplied by API 610 pump suppliers will not be a good solution for this low shearing application. Supplier regrets are attached

To cater the low shearing requirement, positive displacement pump of Progressive Cavity type are used to counteract oil droplet breaking (shear).

Hence, Contractor advises that Progressive Cavity pumps shall cater Produced Water Buffer pump service.

In view of this, Client is requested to approve the Progressive Cavity type pumps for Produced Water Buffer Pumps."

Is there really no supplier who would provide API610 pump for such a service? what are your thoughts?

 

[georgeverghese]

Agreed, getting 107m head with only 4m3/hr is probably a high speed pump - low shear centrifugals are those that run <1000rpm. If you are left with no choice other than these progressive cavity pumps ( Moyno etc), a N+1 configuration for sparing would be the bare minimum. Note that most pd pumps dont do well in fluids with suspended hard solids such as sand.
Else see if you can reconfigure the process scheme to enable a lower pumping head that will suit a low speed centrifugal.

 

[LittleInch]

Well it doesn't sound like it. "Low shearing" is a rather vague term and hence I guess vendors are put off by it and your conditions are at the outer edge of "normal" ranges. Low flow high head pumps are a bit of speciality, but not when you add in "low shearing".

But a 610 pump for this power is serious overkill. Some engineers like it because it means they don't need to make up a specification, but you really only need them for larger higher power pieces of kit.

Progressive cavity pumps are great for oily water. If any particle is small enough to go through the inlet flange then the ump will pass it thorough without an issue and basically you can stuff any od dirty water through it. Other PD pumps aren't so accepting, but a diaphragm pump might do your duty.

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