90 degree vs 180 degree check valve flow characteristics.

dradam

LifeTime Supporter
Mar 10, 2013
187
maryland
I am revamping some of my plumbing this spring . I have a 180 check valve after a sweep elbow after my heater and before my acid input and SWCG. If I go to a 90 degree check valve I can make the new install a bit more streamlined, but I dont know how the flow compares in the 90 degree check, vs the 90 sweep and 180 check valve. I want to maintain as much flow as possible. All 2 inch. any thoughts appreciate. looking at the 2-2.5 jandy 180 or 90 check valves. Thanks
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
15,705
Bedford, TX
D,

For the most part, I doubt that you would ever be able to tell.. Unless you have a 100 miles of plumbing there is no real difference between a 90 degree elbow and a sweep 90 degrees...

I redid a rent house pool with all sweep elbows and "assumed" I'd see a big result.. I saw zero improvement in my flow.

While in theory there should be an improvement, in the real world it is just not measurable.

I suggest that you go with what is the easiest to install.

Thanks,

Jim R.
 
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JamesW

TFP Expert
Mar 2, 2011
17,288
You need to know the flow rate intended for each pipe. For suction, you want to keep the water velocity below 6 ft/sec. For returns, you want to keep the water velocity below 8 ft/sec.

Size.......6 ft/sec......8 ft/sec.
1.5"...........38...............51 gpm
2"..............63...............84 gpm
2.5............90.............119 gpm
3.0".........138.............184 gpm

As long as you keep the water velocity below 6 ft/sec on the suction and below 8 ft/sec on the pressure side of the pump, the difference between a sweep 90 and sharp 90 is minimal.
 
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dradam

LifeTime Supporter
Mar 10, 2013
187
maryland
Thank You, That is very helpful. I usually run at 15Gpm and rarely more that 40 while vacuuming. The return line narrows to 1.5 pvc. do you by any chance have those numbers for a 1.5 inch line? thanks.
 

JamesW

TFP Expert
Mar 2, 2011
17,288
Thank You, That is very helpful. I usually run at 15Gpm and rarely more that 40 while vacuuming. The return line narrows to 1.5 pvc. do you by any chance have those numbers for a 1.5 inch line? thanks.
Size.......6 ft/sec......8 ft/sec.
1.5"...........38...............51 gpm
2"..............63...............84 gpm
2.5............90.............119 gpm
3.0".........138.............184 gpm