Crack in Hayward Super pump housing wth pics

[bobjersey]

PoolDoc thanks so much for your help. Thanks also for combining the post about the screw with this one.

I reassembled the pump housing and motor with a new diffuser gasket and housing gasket. I filled the reservoir with water and just watched it. Sure enough, slowly water started to come out from under the pump housing. Whether it is the crack in the pump housing or a failed mechanical seal there is definitely a leak in this pump. I am going to take your advice and replace the pump entirely.

The most I can make of what's left of the model# is SP XXX5-7-1-M. At least that's what I think it says. I realize this means it should be the 3/4 HP model, but the store we bought it from recommends the 1.5HP for this pool and my mother insists we bought the 1.5HP model.

PoolDoc, do you have any links that explain how to calculate feet of head?

[CarlD]

Please don't succumb to the "Bigger Pump" scam. If you ran FINE with a 1hp for years you don't need more. The smallest 2 speed Hayward sells is a 1 hp SuperPump. I have this and it's been running for 8 years.

How big is your pool (did I miss that?)? I have 20,000 gallons so...unless you have a much bigger pool you won't need more than that.

[bobjersey]

Thanks for the help Carl! Here is all the info I have been able to collect about the pool. Again my dad was the man who knew everything about it so if I have missed anything just let me know and I will try to find out for you.

The system: A Hayward Perflex EC-75 with a Super Pump of unknown HP.

The pool: 20 feet wide x 40 feet long, 3 feet deep in the shallow end and 10 feet deep at the deep end. In ground, vinyl liner, I have heard estimates that it is about 40,000 gallons but I do not know that for sure.

The plumbing: The outer diameter of the piping I see is 5 3/4" in circumference, so I calculate it is 1.83" in outer diameter and I ASSUME it is 1.5" inner diameter. I estimate the length of pipe (underground so I cannot directly measure it) is 52 feet on the return line and 36 feet on the skimmer line. There is one more line, a submerged intake in the deep end but we never use it (this is roughly 15 feet from the pump).

I know it is hard to determine what kind of pump is needed, but any help is much appreciated because we don't have a lot of money. I would really like to get the right pump and not have to worry about it in the future.

Many thanks,
Bob Jersey

[Poconos]

That's a pretty big pool but it is 1.5" pipe so you're pump size is limited by that. I wouldn't want to go with the larger pump with that pipe.
Al

[bobjersey]

Thanks Poconos. My real concern is the length of the plumbing (feet of head) as I have not been able to find how to definitely calculate this. For example I don't know if I should count the return line in the total feet of plumbing, since it is after the pump. If I only count the skimmer to the pump the plumbing may be as little as 36-40 feet, but if I cant the return line as well then it could be as much as 90 feet of plumbing!

Once I know if I can use just the skim line or if I need to use both then I can see what size pump I will really need.

I am stuck between the 1HP and the 1.5HP. The 1HP is rated 39GPM at 50 ft head, and the 1.5HP is rated 53GPM at 50 feet. These are both pretty close to the 1.5inch pipe max of 44GPM per minute, and well below the 80GPM max of the EC-75 filter. I guess I am just worried about breaking the pipes if the pump is too strong.

[Daggit]

Thanks Poconos. My real concern is the length of the plumbing (feet of head) as I have not been able to find how to definitely calculate this. For example I don't know if I should count the return line in the total feet of plumbing, since it is after the pump. If I only count the skimmer to the pump the plumbing may be as little as 36-40 feet, but if I cant the return line as well then it could be as much as 90 feet of plumbing!

Once I know if I can use just the skim line or if I need to use both then I can see what size pump I will really need.

I am stuck between the 1HP and the 1.5HP. The 1HP is rated 39GPM at 50 ft head, and the 1.5HP is rated 53GPM at 50 feet. These are both pretty close to the 1.5inch pipe max of 44GPM per minute, and well below the 80GPM max of the EC-75 filter. I guess I am just worried about breaking the pipes if the pump is too strong.

The feet of head that the pump develops is a differential between the suction and discharge. So, to figure this you need to figure the total elevation change between the pool level and the pump suction (a static head) plus the piping pressure drop in the skimmer line (the dynamic head) and then add that to the same calculation on the discharge side (static elevation change plus dynamic drop through pipe and equipment).

But...don't confuse feet of piping with feed of head. The expected pressure drop through 100 feet of 1.5" piping at 45 gpm is 5.85 psig or 13.5 feet of head. The other equipment in the system will overshadow this.

In practice, the suction-side elevation change and the dynamic drop through equipment on the discharge side have the biggest effect.

I wouldn't worry about breaking the piping unless you know of some reason that it was poorly assembled. Even a conservative pressure rating for the piping of 75 psig equates to 173 feet of head.

[bobjersey]

I emailed Hayward my pool specs and they told me that I should purchase the 1.5HP model (SP2610X15), so that decides it I'm definitely going with the 1.5. Thanks SO MUCH to everyone who helped out here, have a great summer!