Too much pump??

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tjwaggoner

tjwaggoner

0
May 19, 2012
88
Ashland KY
Hello. New member here, been reading for a week or so. Glad to hear any advice.
We just had a 10k gal fiberglass installed (pouring concrete monday) and now that I have the pump and filter up and going, Im afraid my pump may be too much. I am loving how quiet the pump is but getting a lot of noise from turbulence in the return right as it exits the 6-way of the filter. I have a decent understanding of hydraulics as I work in operations in an oil refinery but I am not an engineer. I can pinch my return valves back and increase the back pressure and the noise goes away and it is not there when I switch the filter to recirc. Here is what I have and what my thinking is:
(2) 2" main drain suctions tied together under ground
(1) 2" skimmer
(3) 2" returns (not sure of eyeball size but Im assuming 3/4")
Whisperflo 1.5hp
Sand dollar SD80 (which I believe has a 1.5" 6-way valve which I suspect is causing my problem with turbulence noise due to too big of a pressure drop)
I will try to attach a picture if it will help.
Thank anyone who can give me any helpful advice. Should I go with a smaller pump? Change my impeller/diffuser? Change eyeball size? (though I worry about this effecting longevity of the pump).
 
A 1.5 HP WhisperFlo on a 10,000 gallon pool is certainly more pump than you need, and will make more noise than a smaller pump would make.

You appear to have at least a pair of different problems, a suction side leak letting air in and noise. Each will need to be dealt with separately.

Replacing the impeller with a smaller impeller will give you a pump which is effectively a smaller pump, which will be quieter and use less electricity. It will also reduce the noise level.
 
Im just not convinced I have a suction side leak because the strainer basket window is totally buble free and the pump itself is practically silent...very impressed with its noise level. The gentle churning of the water from the returns masks the pump noise completely. The noise is coming from the section of return immediately after the filters 6-way valve. I didnt ask the builder what model pump there were installing but assumed a cheapo .5hp then the guy brought over this huge filter and 1.5hp beast. I know its not thought of well but I would like to run the thing 24/7 but definitely wont be with this set up. Also I think if the noise was being caused by a suction leak pinching or closing off some returns wouldnt make it go away. Right?
 
We had a 2 HP WhisperFlo and now have a 3hp IntelliFlo on a 38K pool. The pool has a single return pipe (2") that is tee'd to four returns into the pool. I've never noticed any odd sounds from the return pipes, only the sound of the pump itself. Running the IntelliFlo at 1/2 speed makes the pump almost silent, and again, I cannot hear any sounds from the filter or return pipes. I wonder if the valve at the top of your filter is making a bunch of turbulence in the water, causing cavitation (release of trapped air in the water at boundaries). If so, it might be possible to re-plumb that valve to minimize cavitation.
 
My thinking is that it is something with the valve in the top of the filter where my problem is but just dont really know the best route to correct it.
Most expensive: buying a complete diff pump
Less expensive: replacing impeller and diffuser
Even less: replacing eyeballs
Free: pinching return valves way down
I also have a single 2" that it Tee'd to three 2" returns if that makes sense but they neck down to 1.5" where they connect to the pool wall if I looked at it right when they were plumbing it.
I agree though it is turbulence caused by a pressure drop across the valve in the filter. There isnt any sharp 90's on it either, its plumbed pretty smooth and gradual until it splits into the 3 separate return lines.
 
My guess is that the valve causing the noise. You can call Pentair but I doubt there's anything they can do.

An easy try would be to route the piping right out of the filter about a foot higher than the valve. It would change the hydraulics a little and may be enough to silence the noise without affecting the head much.
 

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Yeah I will definitely wait until I get it installed. Fedex tracking number says it will be delivered the 24th. Hopefully it puts enough backpressure on the return to quiet it down some. It not a terribly loud noise but I like how quiet that whisperflo is.
 
I agree with the others that a 1.5 HP Whisperflo is overkill for that pool. A 3/4 HP two speed Whisperflo would been on the high side. But with dual suction and three return lines, the head loss is probably pretty low in that part of the plumbing which means the water velocity in the pipes is probably pretty high and making noise.

What is your filter pressure?

How many return eyeballs do you have in total or per return line?

One thing to try is turn off two of the three return lines, the noise should go away and filter pressure rise.
 
Looked at filter before I left for work this evening and it was right around 20psi
I have 1 eyeball in each of the 3 returns
Yes Ive closed off returns and the noise goes away. I may try putting smaller eyeballs in 1 or two of the return jets
 
If it isn't too late, I would have them fix a couple things.

Replace the pump with a WFDS-3 or 24.
Replace the backwash valve with a 2" valve.

This is what they should have done in the first place.
 
I would ask anyway but you can always replace the impeller. It is a fairly easy and inexpensive what to downsize a pump.
 
Thats probably the route I will take. Experimented a little bit this morning, pinched back the 3 return valves and it got quiet and still had plenty of water circulation. But when I did it I noticed two very small bubbles in my strainer basket window that arent there when I open them all the way. They were very small like maybe each the size of a pea.
 

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