Pump Outlet Size, Pipe Size, and Head Loss

catastrofe · 09/19/2006, 10:11 AM

Is there any benefit to increasing the pipe size on pump outlets?

In other words, if my pump has a 3/4" out, is there a benefit to converting that to 1" with some fittings? Wouldn't reducing it back down to 3/4" for a Locline fitting at the tank negate any benefit?

The head loss calculator here on RC shows a huge improvement when upping the pipe size for any particular pump.

sjm817 · 09/19/2006, 10:14 AM

Yes. Some pumps benefit more than others. A "pressure rated" pump does not need the increased diameter as much as a flow pump. For instance, a Mag Drive which is a flow pump benefits quite a bit. You should double the outlet size on a Mag.

catastrofe · 09/19/2006, 10:16 AM

Won't I lose the benefit when I reduce it back down for my Locline return?

How about an Eheim 1262?

Thanks for the quick response.

RichConley · 09/19/2006, 10:18 AM

No, the increase in head pressure is due to friction. The longer the run, the more bigger piping will help. Yes, choking it down to 3/4" locline will reduce flow some, but not nearly as much as running all 3/4"

sjm817 · 09/19/2006, 10:19 AM

It has to do with frictional loss in the pipe. The little outlet at the end doesn't affect that. For a submersible, the Eheim pumps are very good in this respect (and others). I would use 1" plumbing on a 1262.

catastrofe · 09/19/2006, 10:21 AM

Thanks!

09/19/2006, 10:11 AM	#1
catastrofe Registered Member Join Date: Aug 2003 Location: Saint Louis Posts: 778	Pump Outlet Size, Pipe Size, and Head Loss Is there any benefit to increasing the pipe size on pump outlets? In other words, if my pump has a 3/4" out, is there a benefit to converting that to 1" with some fittings? Wouldn't reducing it back down to 3/4" for a Locline fitting at the tank negate any benefit? The head loss calculator here on RC shows a huge improvement when upping the pipe size for any particular pump.

09/19/2006, 10:14 AM	#2
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	Yes. Some pumps benefit more than others. A "pressure rated" pump does not need the increased diameter as much as a flow pump. For instance, a Mag Drive which is a flow pump benefits quite a bit. You should double the outlet size on a Mag. __________________ - Scott

09/19/2006, 10:18 AM	#4
RichConley Registered Member Join Date: Sep 2004 Location: Bostonian in Chicago going to DC Posts: 9,908	No, the increase in head pressure is due to friction. The longer the run, the more bigger piping will help. Yes, choking it down to 3/4" locline will reduce flow some, but not nearly as much as running all 3/4" __________________ NO TANKS!!!

09/19/2006, 10:19 AM	#5
sjm817 On Yer left! Join Date: Sep 2004 Location: Northern VA Posts: 18,777	It has to do with frictional loss in the pipe. The little outlet at the end doesn't affect that. For a submersible, the Eheim pumps are very good in this respect (and others). I would use 1" plumbing on a 1262. __________________ - Scott

09/19/2006, 10:16 AM	#3
catastrofe Registered Member Join Date: Aug 2003 Location: Saint Louis Posts: 778	Won't I lose the benefit when I reduce it back down for my Locline return? How about an Eheim 1262? Thanks for the quick response.

09/19/2006, 10:21 AM	#6
catastrofe Registered Member Join Date: Aug 2003 Location: Saint Louis Posts: 778	Thanks!