Plumbing sizes

[diablo243]

Hey all, getting ready to plumb my new build. I'll be dropping down to the basement for the sump and other various items. I have a 90RR that is drilled 1" for drain and 3/4" for return. When I come out of the sump I plan on putting in a few Ts with valves for future expansion. My question is should I come out of the sump with 1" and build all my expansion valves that size, then once back at tank reduce to 3/4 or just keep the whole thing 3/4?

Thanks all!

 

[NeptuneGarden]

Go as big as you can on the return. 1.5" would not be bad idea. It will greatly reduce your friction loss and increase pump efficiency.

 

[diablo243]

Even if it ultimately has to reduce back to 3/4 at the tank?

 

[NeptuneGarden]

Even if it ultimately has to reduce back to 3/4 at the tank?

Yes. Especially when pumping long distance up out of the basement

Lets run the numbers through a calculator
http://www.freecalc.com/fricfram.htm

10gpm/600gph through 3/4" pipe with 20' of lift = 1.97psi or 4.5 feet of head loss - this is just from the friction of the pipe from pump to the back of the tank ... not counting any turns or T's in the system which add even more friction loss

now lets run same numbers with 1.5" pipe with 20' lift = 0.07psi or 0.2 feet of head loss.... plus all the T's and elbow will restrict flow much less as well.

I've always been amazed how much flow you can picked up, even on short 4' run from a sump directly under the tank by over sizing the return pipe.

 

[diablo243]

Wow awesome info! That helps a lot!

 

[Rjramos]

Even if it ultimately has to reduce back to 3/4 at the tank?

Speaking from a Firefighters knowledge regarding friction loss, the 3/4 " bulkhead at the bottom of the tank determines the maximum volume you can get through . Increasing the volume of the pipe before this to 1" will be better than 3/4" pipe from the pump,however anything larger than 1" will not improve volume going through at the 3/4" bulkhead. I asked a tank manufacturer once why 3/4" on the return instead of 1"? He told me it was to prevent installations where the water volume coming in is greater than your drain volume (by gravity). Possibly overflowing the tank. Hope this helps[emoji4]

 

[NeptuneGarden]

If you can afford them high pressure sweep pvc fittings help a lot as well.
Look like the pvc drain sweep fittings you can get at Lowe's and HD, but have deeper pressure rated glue joints. Not cheap though.
https://flexpvc.com/cart/agora.cgi?product=PVC-Fittings-Elbows-SpearsSweep90s



It's not about increasing the volume of water with a large pipe, it's about increasing the efficiency of moving the same volume of water. This leads to being able to use a "weaker" pump to move same amount of water over the same actual head height for much less energy - especially when added up 24/7/365 on a return pump ......

 

[diablo243]

Great stuff thanks everyone!

 

[Rjramos]

If the pump has a 1" out then go with 1" and reduce to 3/4" at the bulkhead and beyond. If the pump like a Reeflo or one of the newer DC pumps has a larger 1 1/4" or 1 1/2" outlet then go with that diameter up to the 3/4" outlet. I have done many installations through dual 3/4" bulkheads where a pumps output can easily exceed the capacity of dual returning overflows. The important thing to getting the desired turnover is getting a pump that has the head pressure to overcome the head height and the restriction at the 3/4" bulkhead. PSI.

 

[NeptuneGarden]

Suggested reading
http://www.pumpfundamentals.com/centrifugal-pump-tips.htm

Useful calculators
http://www.pumpfundamentals.com/applets.htm#applets4

 

[AZDesertRat]

Go as large as possible until the last moment. The 3/4" bulkhead on the display will reduce flow a little bit not nearly as much as using all 3/4" pipe due to the increased velocity and resulting headloss. Actually most pump manufacturers recommend increasing the pipe size. With aquarium pumps a one or two foot headloss can have a major effect on flows since they are low head pumps by design.