Pro/Forums - View Single Post - Lowering Pump inlet restriction. (Eheim 1250)

pippin88 · 04-12-2004, 02:04 AM

After reading a Procooling article (which used my system from over a year ago as an example) about resistance on the pump inlet, I've been thinking of how to reduce it.

Some of you may be familiar with the Eheim 1250's inlet structure. I has the threaded inlet tube (Where barb screws in) attached to a plate with an O-ring seal, that forms the inlet wall of the impellor chamber. This is held on by a ring that you twist into place until it locks.

My questions?
Is the inlet wall of the impellor chamber important to the pumps function (I assume it is essential)?
How come such a large benefit can be had from lowering restriction, when the actually size of the inlet is 3 small slots?

I plan to do something similar to what pHeatus did with his pump using a PVC piece, but I'd like to not have it permanent (ie glue), so I'd like to machine a piece to actually function as the locking ring as well as a mini res on the inlet. Would this give much benefit, as the inlet would not have a barb on it at all, rather it would just be in free water.
How big a restriction free area is best? 5cm, 10cm before tubing?

04-12-2004, 02:04 AM	#1
pippin88 Cooling Savant Join Date: Oct 2002 Location: Australia Posts: 285	Lowering Pump inlet restriction. (Eheim 1250) After reading a Procooling article (which used my system from over a year ago as an example) about resistance on the pump inlet, I've been thinking of how to reduce it. Some of you may be familiar with the Eheim 1250's inlet structure. I has the threaded inlet tube (Where barb screws in) attached to a plate with an O-ring seal, that forms the inlet wall of the impellor chamber. This is held on by a ring that you twist into place until it locks. My questions? Is the inlet wall of the impellor chamber important to the pumps function (I assume it is essential)? How come such a large benefit can be had from lowering restriction, when the actually size of the inlet is 3 small slots? I plan to do something similar to what pHeatus did with his pump using a PVC piece, but I'd like to not have it permanent (ie glue), so I'd like to machine a piece to actually function as the locking ring as well as a mini res on the inlet. Would this give much benefit, as the inlet would not have a barb on it at all, rather it would just be in free water. How big a restriction free area is best? 5cm, 10cm before tubing?