DPM 2340 - Which Direction Should Filter Pump Run?

[jpfulton248]

We have been suspicious of our filter pump since we bought our DPM 2340 a couple years ago. About a month ago I took everything apart related to the pump, filter and hoses, cleaned it and put it back together. We are investigating more today and have noticed the direction of the chemical seems odd. It seems to be pulling from the hole at the top right of the processor reservoir. From there it goes to the location on the filter marked "OUT" then from there it goes presumably to the "IN" and then down to the pump and then presumably goes to the big hose and up to the bottom of the processor tank.

This seems total backwards. Can anybody tell me what direction the chemical should be flowing? It seems like it should be going down through the hold in the bottom of the processor tank and then into the pump (although that seems odd too) and then into the filter where it is marked "IN" and then "OUT" and then to the hold on the top side of the processor tank where it drops back in.

Any info is appreciated. Thanks!

 

[old guy]

is probably the way abdick/presstek set it up. otherwise sediment would go down the big hole into the pump. i quit trying to understand abdicks thinking when they came out with the 430

 

[jpfulton248]

That was my thought... that going straight into the pump would also not be a good idea. Personally I would think going from bottom of the tank, into the filter, into the pump and back up to drop in at the top of the tank seems to make the most sense but that's just my intuition.

 

[Deleted member 16349]

That was my thought... that going straight into the pump would also not be a good idea. Personally I would think going from bottom of the tank, into the filter, into the pump and back up to drop in at the top of the tank seems to make the most sense but that's just my intuition.

One might put a screen before a pump but it is not a good idea to put a filter before a pump that will cause a pressure drop. Normally filters are after the pump, on the high pressure side. If a filter is put before a pump, there is the good chance that the pressure drop will cause the cavitation on the suction side of the pump and possibly destroy the pump.

 

[jpfulton248]

One might put a screen before a pump but it is not a good idea to put a filter before a pump that will cause a pressure drop. Normally filters are after the pump, on the high pressure side. If a filter is put before a pump, there is the good chance that the pressure drop will cause the cavitation on the suction side of the pump and possibly destroy the pump.

Interesting... what are your thoughts on my situation in general, does pulling the chemical from the very top of the tank (like a half inch below the fill line) and then pushing back up into the bottom of the tank seem backwards to you?

 

[Deleted member 16349]

Interesting... what are your thoughts on my situation in general, does pulling the chemical from the very top of the tank (like a half inch below the fill line) and then pushing back up into the bottom of the tank seem backwards to you?

Trying to read your original description carefully, it does seem the piping is wrongly connected. I don't know the logic of the original designer of that system but I would tend to think it should be:

Pull the solution out from the bottom of the tank, to the pump IN port, from pump OUT port to the filter IN port, from the filter OUT port to the upper level of the tank. To protect the pump from large objects (nuts or bolts fallen into the tank etc.) a high flow screen unit can be placed before the pump.

I would assume that the pump is a centrifugal pump. The IN port of such a pump is in the center and the OUT port is on the circumference. If the motor drives in one direction or the other on this kind of pump, the flow direction is the same but at different pressures.

I suspect that all you need to do is swap the piping lines so that the pump is being fed to the center from the bottom of the tank and the output goes to the filter.

It is best to check with the supplier on what they are actually trying to do and how they specify how the pumping system should be connected.

Good luck.