eVOLVER Forum

How can I verify the pump is correctly actuating and spinning?

What should we do if there is no flow through a pump after ensuring connection of the upstream line? Thanks!

Hi Ariel. Can you give more specifics? Like is the pump spinning? Or is the motor spinning but not the pump? Are there any dried media in the lines?

Hey Brandon,

How can I tell the difference between the pump spinning and only the motor spinning? Something was spinning, but I don’t know if it was just the motor or not.

The lines were clear of any dried media; there was only air in the lines earlier, and then just DI water when the pump stopped pumping.

(Interestingly, it’s both the influx and efflux for a single vial that aren’t working, but it might just be a coincidence.)

Thanks!

Is just the metal rod spinning or are the metal rod and the white plastic piece both spinning? There are two latches on the side of the motor that you can take off the pump head. That should make it more obvious.

Only the metal rods are spinning, the white plastic pieces aren’t spinning.

OK so if this happens, we typically spray some adhesive into the center of the pump to get a bit more friction on the metal rod. This is the adhesive we use, just spray some (~0.5s) at the top while the pump is running, let run until pump returns to full speed. The Khalil Lab has some if you want to borrow from them.

EDIT: I’ve found what works better is spraying the adhesive on a paper napkin and just wiping the the adhesive on the metal rod, with the pump head off, when the metal rod is spinning. This makes sure the adhesive doesn’t prevent the plastic parts of the pumps from working.

I did this and it seemed to improve the adhesion between pump and rotor for almost all the pumps, but some pumps are not returning to full speed, even after giving it some time to rest and trying to add more adhesive. The metal rods are still spinning in this case, but the white pieces are hardly spinning with it.

Taking the pump heads off and readjusting should also help. That should also determine how much adhesive the metal rod has on it. If you want, you can take apart the entire pump to ensure that the adhesive still allows the plastic parts to turn.

So to add on this point, I found out the best way to spray the adhesive on the rod is the following steps:

  1. Spray adhesive on a paper towel
  2. Take the pump head off
  3. Actuate the pump and run the paper towel (w/ wet adhesive) onto the spinning metal rod.

This helps minimize the mess and the coating a bit more controlled.

1 Like