Off season upgrading

[rickily]

Hi TFP denizens,

I've been learning in the background for over a year now and the first thing I would like to say is "Thank you to all for the wealth of info that you guys provide."

I made it thru my first year as a newbie pool owner with very little problems except one small algae bloom easily taken care of with the BBB method as found within this forum.

Now that winter is here, it is time for me to start on some ventures of equipment changing and upgrading that cannot be easily done during the swimming season.

My pool: ~1980's rectangular 24K gal. IG gunite w/ stainless steel upper panels (no tile), 1 main drain, 1 skimmer, 2 returns, 1.5 hp Hayward Superpump, Hayward side-mount sand filter, 1.5 inch plumbing.

Swimming season pool maintenance is no problem (less than 5 min./day), so, my main goal for the upcoming season is optimum energy savings with no loss in pool performance.

Following are some of the problems with my pool setup that I will be considering to fix (please correct me if I'm wrong, and add opinions, also)

1. Pump is too big and inefficient
2. All piping on the equipment pad is poorly routed and inefficient.
3. There is no label on the sand filter to indicate what size it is and know if it's the right size for my pool,(although it seems to filter just fine)

So, starting with Problem 3, How do I confirm which Hayward filter I have with no label?

Problem 2, I have decided to tear out all plumbing on the equipment pad and redo. I even dug up and removed the entire length of suction line all the way to the skimmer because first, it wasn't too big of an job, and second, it's no problem to increase sizing of suction line from skimmer to, hopefully, better help my hydraulic situation.

Questions with Problem 2 (keeping in mind that I will eventually be changing pump to probably a 2 speed in the near future)

1. Will I benefit by increasing skimmer suction line size when I cannot change main drain suction line size?
2. Where is the best place to install check valves in a typical piping system such as mine?
3. After handling all of the above, I need help in determining which pump to upgrade to as I get very confused in hydraulics, head and pump curves.

Thanks in advance for any advice given.

 

[JasonLion]

Welcome to posting at TFP!

The essential information about the filter is the diameter. Given the diameter you can narrow down the design flow rate, etc, closely enough for your purposes. An exterior measurement will be good enough. The internal diameter will be about 1 inch smaller. If you want to narrow it down to a specific model you could look through the pictures at the Hayward web site.

Do you know if the pump is 120v or 240v? The number of amps available may also constrain your choice of replacement pumps.

The big question on the pump is how much money you are willing to spend. You could simply get a smaller single speed pump, get a two speed pump, or get a variable speed pump. As you move along that list the pumps get more energy efficient and also cost more. The possible price range is something like $300 to $1200.

1) Yes. Though increasing the pipe size will only make a small difference.
2) A simple setup like yours only rarely needs a check valve. Why do you think you need one?
3) You don't really need to know that much about hydraulics. For a simple setup like yours it is mostly a question of how much money you want to spend.

 

[mas985]

The Hayward 1.5 HP Uprated SuperPump is actually not that "large" of a pump. In fact, in terms of braking HP it is smaller (1.5 BHP) than my 1 HP Full Rated Northstar (1.85 BHP).

However, if you want to reduce your electrical cost even further there are some options as Jason pointed out. One I would add to that list is if the pump is fairly new, you could just replace the motor with a two speed. The SuperPump has a two speed version so it shouldn't be too hard to find a replacement motor for around $200.

If you were to replace your 1.5" suction line with 2.5" all the way to the skimmer, then I think you will see a fairly large reduction in suction head loss. What this would mean on total head loss depends on what the return head loss is. You can get a fairly good idea by the filter PSI. Also, with the main drain still at 1.5", the increase in flow will mainly be from the skimmer but I think that is ok and probably better anyway. You don't need much draw from the main drain for decent circulation.

I could run some head loss numbers for you but I need some additional information:

Current Filter PSI
Pool to pad suction run pipe length
Pool to pad return run pipe length (I assume there is only one return run)

I can estimate your approximate flow rates with your current pump and any pumps you are considering

 

[duraleigh]

Rickily,

Welcome! I can add little to what Jason and Mark have already provided except that I am not a fan of check valves. Like Jason, I doubt you need them and I would avoid them if at all possible.

 

[Titanium]

Rickily,

Welcome to the forum!

We need pictures. :!:

Titanium

 

[pooladdict]

Sorry to somewhat hijack this thread, but isnt the main purpose of a check valve to stop a water back up, such as a solar system to insure the water doesnt go up the out when the in is shut off?

 

[JasonLion]

A check valve allows water to flow in one direction but not in the other direction. One common use is with a raised spa to prevent water from flowing out of the spa and down to the pool backwards through the spa return when the pump is off. The check valve allows the water to come into the spa but it can't go back out. A check valve is sometimes used when the pump is raised well above the pool to prevent the intake pipe from draining back to the pool when the pump strainer basket is open. With water in the pipe the pump has less trouble priming when it starts up. Another use would be on the return from a solar system to keep the pump from pushing water backwards through the solar panels when the solar feed is shut off. Sometimes a check valve is used to prevent chlorine from a puck feeder or SWG from going backwards into the heater when the pump turns off.

 

[crabboy]

My pump is about 2 feet above the level of the pool and the check valve, that is right before the pump, speeds up the time to prime the pump after the pump basket has been emptied. it took a few minutes for the pump to prime before the valve was in.

Gary

 

[rickily]

Thanks for the advice so far. The reason I have asked about check valves is that when I shut off my pump there seems to be a lot water going somewhere out of the pump strainer pot. So much in fact that the pump will not reprime without adding water to the pot.

Now a question about increasing the pipe sizing to the skimmer. Being as that I cannot change the oriface size at the bottom of the skimmer box from 1.5 inch and I cannot change the oriface size at the pump strainer pot from 1.5 inch, won't these two smaller "restrictions" actually not allow any advantage (from increasing the pipe size) to happen.

Thanks mas985 for the info on the Superpump actually coming in a two speed version. That is very interesting.

 

[JasonLion]

Larger pipe will help even if the pipe narrows in a few places. Resistance to flow is summed over the entire length of the pipe run. If most of the pipe run is made larger, the resistance to flow in the larger pipe areas will go down, improving the overall water flow. The water does have to flow faster in the narrow sections, increasing the resistance slightly in those areas, but as long as the narrow areas are kept short that resistance will be trivial compared to the improvement over the rest of the pipe run.

On the check valve issue, what you describe sounds like it is probably caused by an air leak. If it is an air leak then a check valve won't help significantly. I would try double checking the pump strainer basket lid. Make sure the seal on the lid is clean and free of dents or cuts and that the lid is fully on and tight.

 

[rickily]

I did notice a few champaigne bubbles coming from the returns every 5 or 10 seconds so when I replumb I will focus on making sure of no suction side leaks (again....more below).

When I first bought this pool last Dec. (house came with it) I tried every trick I could find in this forum to eliminate the champaigne bubbles. I made sure of not sucking air thru the skimmer by adding enough water to the pool, I siliconed every suction side pvc joint, I bought a new gasket for the lid, isolated each suction line, and even tried all the tricks with water, shaving cream, smoke, and the like trying to trace the leak down. I finally reduced the bubbles to a "spurt" of bubbles every 5 or 10 seconds which I finally attributed to cavitation because the pump seemed too big for my system. Which brings up a simple question.

Is there a test to perform to prove if the pump is actually cavitating or is it "process of elimination of suction side leaks"?

Mas 985, I will get the numbers you requested soon and post them.

 

[mas985]

Cavitation is probably very unlikely. The suction has to be large enough to draw air from the water effectively boiling the water. This usually means that you have a blockage somewhere in the suction side of the plumbing. Also, with cavitation, the air bubbles disolve back into the water shortly after the pump so you really should not see them coming out the return.

It is more likely that you still have an air leak somewhere and just need to find it. You don't have a SWG do you? That will also cause small bubbles.

 

[rickily]

No SWG.

It seems that the previous owner left all the equipment on the pad uncovered and unprotected all season long, which is one reason I have decided to replace all the plumbing on the pad. The other reason of course, as I stated in my original post, the plumbing design was very poor and, I'm sure, sun degraded.

So, when I get everything replumbed and reinstalled I will keep trying to track down the suction side leak.

Is it possible that there may be a problem with the pump housing and/or connection of pump strainer basket pot and housing.

Oh, BTW, I installed SS 1/4 inch ball valves and RTVsiliconed them in the drain plug openings during my search for the suction leak, so I know it's not the plugs. And as I stated earlier, I siliconed every pvc joint I could get to on the suction side of the pump, so I'm pretty sure the leak has to be around the pump and/or basket lid somewhere.

Maybe I'll get lucky and when I replumb everything the problem will have disappeared. As it is still early in the winter, in may be a little while before I undertake the replumb job. As for right now I'm trying to "plan my attack" so I will everything ready in my mind of how I want the end result to be. I would like to even have the "end result" pump purchased and ready to install at that time, so continued advice on the pump sizing is appreciated.

There will be no extra water features added to the pool, so the basic design of plumbing layout will not change.


I'm going to try and attach the layout of my pool. I'm new to this so I hope it comes thru.

When looking at the layout remember that suction line from main drain goes down vertically ~10 ft.... so 10 ft. should be added to the distance of actual piping to the main drain.

Also take into account that the piping from skimmer box to pump will be replaced with size that you recommend...2.5 inch?
All other piping will remain 1.5 inch.

 

[mas985]

A couple of observations first, it is good to have parallel runs of pipe. 2 runs of 1.5" is about the same head loss as one 2" pipe.

Also, one thing I noticed about your current set up is that the suction side has almost the same head loss as the return side which usually causes problems with the pump sucking air. Pumps prefer much lower head loss on the suction side so replacing the pipe will help with this as well.

Also, if you can give me your current filter PSI, I can get a bit closer but here is what I have so far.

With your current setup, I estimate about 50.5' of head @ 51.2 GPM.

By changing your skimmer pipe to 2.5", the head loss is about 42.3' @ 61.4 GPM. So you can gain about 10 GPM with the pipe change.

If you went with only 2" pipe, then the head loss is 44.7' @ 58.5 GPM

An 8 hour turnover is about 52 GPM which is actually pretty close to where you are now. A two speed pump on low speed will about halve all of the GPM numbers and double all of the turnovers.

If you want 3 turnovers per day for heavy loads and hot summers, then you want a pump pretty close to the one you have. However, it would be nice to have the capability to run slower & more efficient when you don't need 3 turnovers so at least a two speed would help.

 

[rickily]

The dimensions I get on the filter are 23 1/2 in. wide (outer flange width) by 36 in. tall (base to top of air relief plug) which seem to be the dimensions of the Hayward S200 High Rate Sand filter (please correct me if needed) according to the Hayward documentation.

The pressure normally runs 15 - 16 psi. with filter clean and both suction lines 100% open.

The pool has a very light bather load. Maybe once per month more than 2 people in a particular day.

Any advice on if there may be problems with the pump housing or connection between pump housing and strainer pot? This question is important to me because I'm sure it would be cheaper to purchase entire pump assembly instead of buying one piece at a time.

 

[JasonLion]

The Hayward S200 has a design max flow rate of 44 GPM. The S244S also has the same external dimensions and a design max flow rate of 62 GPM. It is fairly easy to tell them apart. The S200 has a substantial flange around the middle, perhaps 2/3rds of the way up. The S244S has a more uniform main container without an obvious seam. If you have the S200 then it is too small for you current pump, though just large enough for the pool. If it is an S244S then it is nominally large enough for the pool and pump, but I would still recommend getting a larger (oversized) filter if you can.

Getting an oversized filter has a number of advantages. There is less resistance to flow, so the pump moves more water using the same amount of electricity. You don't need to backwash as often. And filtering is slightly more efficient (there is a lower flow rate per unit of sand, so the sand traps more stuff).

 

[mas985]

The pressure normally runs 15 - 16 psi. with filter clean and both suction lines 100% open.

That is a bit higher than I expected so with that I have some revised estimates.

Current Setup: 46 GPM @ 54' head & 15 PSI
2" Suction: 51.3 GPM @ 50.4' head & 18 PSI
2.5" Suction: 53.3 GPM @ 49' head @ 20 PSI

The higher pressure could be a result of the filter being smaller than I had assumed which generally means more head loss. It is running about 3 PSI more than what I would have thought.

 

[rickily]

There is an obvious seam half way up that bolts the two halves (upper and lower) together so it seems I have the S200. So, I'm going to have to see if a filter is in my budget also.

Which ever way I go for now, it's obvious I'm going to have to replace the suction line to the skimmer because I have it already torn out. I will be replacing it with 2.5 in. as advised.

 

[mas985]

Yes, there are diminishing returns. You can see that from the GPM. Most of the gain comes from 1.5" to 2" (+5 GPM) and 2" to 2.5" (+2 GPM) is much less. Other factors start to override the benefit of larger pipes so I would say 3" will probably not buy you anything and you could even say that 2.5" is not necessary. However, since you have everything torn up you might as well put in 2.5".

 

[rickily]

Time to start repiping

Hi again TFP denizens.

I'm reopening (or continuing) this thread because it's early Feb. and time to actually start repiping this project that I started in the fall.

With advise from Mas985 I had decided to replace the suction side side piping with 2 1/2 inch because I had already torn out the piping anyway.

Now the problem......I can't seem to locate 2 1/2 inch PVC anywhere.

Local hardware stores, Lowes, Home Depot, Local pool supply stores, McJunkin Red man Corp.......no 2 1/2 inch PVC.

Anyone with suggestions?