I have a problem with some raw water (it usually has sediment and gunk) that I need to pump from below ground level. I came up with something that looks like the image attached to get cleaner water out, but the pump is only sucking the water out of the filter (I filled the pipes with waters first), and not pumping any of the water that is underground. I know that the pipes would have looked cleaner if I had rotated the pump, but I had to workaround some constraints.

I am using a DAB KDF 30/16 pump (1/2hp), the filter is 10", the piping is 1", and there are a total of 7 90' elbows and 1 tee at the intake (there are some extra turns that I couldn't draw in 2D). I'm also using a strainer with a check valve submerged underwater.

I'm pretty sure my pump is working ok, but there most be something impeding it from pulling water. Any ideas what could be causing this?

Crude diagram of my setup

  • 1
    Did the instructions say anything about NPSH - Net Positive Suction Head? Pumps typically want to see a positive pressure at the inlet. Your diagram shows an elevation gain, plus a lot of piping resistance, plus a pressure drop across the filter - all on the inlet side. That's a lot of resistance to overcome.
    – Mark
    Jan 20 '20 at 4:12
  • Is this a self priming pump
    – d.george
    Jan 20 '20 at 12:31
  • Would it be possible to dig out where you are pumping from for a sump-pump with a basin? Of course you'd need to get power to it, but that seems like the right solution for your issue. Jan 20 '20 at 18:57

Is that filter housing rated for vacuum? One possibility is the vacuum is causing cavitation at the pump or a slight air leak at the housing that’s why I asked if the filter housing is rated for vacuum. Having a restriction (filter) on the inlet will reduce the pumps ability to work correctly. for example having to prime all that, just a little air and the pump cannot pull though the filter, if it’s having issues with a clean filter it will be impossible with a dirty one.

I would be locating the pump prior to the filter. Having a screen is fine but the sediment filter will make it much more problematic if you can ever get it to work.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.