Pool plumbing- 90 degrees angles

Nicky ATX

New member
May 24, 2020
1
Austin, TX
Hello,
We are in construction of a new fiberglass pool (size: 33' * 15', about 11,400 G) and just had plumbers this week connecting the equipment. I know 90 degrees angles are not recommended but because of the location of pool / equipment, we have at least 5-6 of those between the two. Can anyone take a look at the pictures attached and tell me if pipes arrangement make sense? If there's any tips to make it more efficient?

IMG_1269.jpgIMG_1273.jpgIMG_1274.jpgIMG_1275.jpgIMG_1276.jpgIMG_1277.jpg
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
12,415
Houston, Texas
What kind of filter do you have? Is your pad plumbing complete or do they intend to put some sort of valve on the filter?
 

doug wilcox

In The Industry
May 8, 2020
50
pa
the least you should use 90 degree sweep elbows and
clean up the runs on the pad.
why put in a fancy pentair energy efficient pump and not
use to its full potential?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
17,833
Bedford, TX
I highly doubt that anyone could tell the difference in the operation of the pool, or pump, between using Sweep 90's or straight 90's.. I suspect there is some minor theoretical advantage, but in real life it would not be enough to even notice.

High efficiency VS pumps move water at such a slow rate it just does not matter.

Thanks,

Jim R.
 
  • Like
Reactions: Nectarologist

doug wilcox

In The Industry
May 8, 2020
50
pa
here is a bit of knowledge.

you can hear the difference between the water running through a 90 elbow to a sweep elbow.

the good people of ca spent a lot of money and time writing the cec code.
here is some of the language below so you can be educated.
pay attention to letter a and to letter c.
if you are going to do something , try to do it right or at least to a written, proven code

from 2019 cec

2. System piping.
A. A length of straight pipe that is greater than or equal to at least 4 pipe diameters shall be installed before the pump; and
B. Pool piping shall be sized so that the velocity of the water at maximum flow for auxiliary pool loads does not exceed 8 feet per second in the return line and 6 feet per second in the suction line; and
C. All elbows shall be sweep elbows or of an elbow-type that has a pressure drop of less than the pressure drop of straight pipe with a length of 30 pipe diameters.

doug
 

doug wilcox

In The Industry
May 8, 2020
50
pa
Screen Shot 2020-05-26 at 9.37.21 PM.pngScreen Shot 2020-05-26 at 9.37.21 PM.png

see above.
when you reduce the tdh, the system is more efficient.
the difference is quantified and you can tell the difference on your electric bill.
qed
 

JamesW

TFP Expert
Mar 2, 2011
19,253
when you reduce the tdh, the system is more efficient.
the difference is quantified and you can tell the difference on your electric bill.
The example shows a total system head loss difference of only 3.2 feet of head at 60 gpm.

That's a very minor difference.

In addition, a residential pool would rarely need to exceed 40 gpm.

At 40 gpm, the head loss difference drops to about 1.4 feet of head, which is insignificant.

Many pools can run at 20 gpm, which reduces the total head loss difference to about 0.35 feet.

The key rule is to limit the return velocity to 8 feet per second and the suction to 6 feet per second.

As long as you follow the velocity rules, the hard 90s won't make a significant difference in power usage or noise.

If the code calls for sweep 90s, then you have to use sweep 90s.
 
Last edited:

jimmythegreek

TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
2,415
Morris Cnty NJ
Good point James. I'm in the group that likes to he as efficient as possible. Takes no more time to use a sweep as it does a street 90. Looks better too. I'm religious with sweeps and even heat bending some pipe. It prob doesnt matter in the big picture but I have a plumbing/hvac background many years ago and its burnt into my OCD brain
 
  • Like
Reactions: jonpcar and JamesW

ekim

Member
May 4, 2013
17
nj
When I looked for long radius sweep elbows all that I found were DW fittings rated for something like 5 PSI. Are long radius sweeps common for pressure applications?
 

JamesW

TFP Expert
Mar 2, 2011
19,253
When I looked for long radius sweep elbows all that I found were DW fittings rated for something like 5 PSI. Are long radius sweeps common for pressure applications?
They're not common or uncommon. You can get them, but they're more of a speciality item that would be available mostly at plumbing supply places and not at hardware stores.

They are a better choice than hard 90s.

For someone who does plumbing all the time, they should probably use the sweeps.

For someone who just does a single project, it's probably not worth chasing down the sweeps.

The most important thing is to follow the velocity rules.
 

doug wilcox

In The Industry
May 8, 2020
50
pa
last comment on this topic

sweep elbows are good when used.

however letter A from above is just if not more important.

A. A length of straight pipe that is greater than or equal to at least 4 pipe diameters shall be installed before the pump; and

it looks a bit short going into the pump.
see note below

(however it works and this is america and i will plumb things the way i want
in my own backyard)

doug
 

JamesW

TFP Expert
Mar 2, 2011
19,253
For pumps without a strainer, the straight pipe is important.

For pumps, like pool pumps, the straight pipe is not that important, in my opinion.
 

jimmythegreek

TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
2,415
Morris Cnty NJ
I have yet to see install instructions for a pump that dont stipulate a minimum length of straight pipe. I agree velocity is the key. Alot of plumbers dont really know much they just know how to work with PVC amd learned from PB guidance. My guy stamps the permit and worries about the gas line. I usually handle all plumbing amd hes my helper occasionally. It's easy money I bust his chops all the time. On no heater jobs hes somewhere else

Side note....Lowes carries sweeps in 1.5 and 2 inch in their schd 40 section. All supply houses have them in stock I've been to
 
Last edited: