How to compare two rotary vane pumps

[markk2pe]

Our original design used a rotary vane pump that had 4 vanes. It was rejected by the customer because they prefer flanged connections over threaded NPT connections. The vendor offered a replacement pump that was the same size and had flanged connections, but he doesn't have any curves for that pump with fluid of the same viscosity as we are using. The pumps seem very similar except the original pump had 4 vanes where the replacement pump has 8 vanes.

I'm looking for some kind of calculation I can use to compare the 8 vane versus the 4 vane, or other ways to compare and evaluate the replacement pump. Any help would be appreciated.

Thank You

 

[btrueblood]

What fluid do they have data for, and how far off is the target fluid viscosity? Can you look at the same fluids in the original pump and see if there are any differences in the pump curve? How hard would it be to rig up a test for the fluid of interest?