Repeated Shaft Seal Failures

[uloset]

I've had shaft seals fail on 3 separate pumps in the last 2 years. My original Hayward Super Pump's seal lasted at least 9 years as I inherited it with the the house. I then ordered a Superflo VS last year hooked it up immediate it sprung a leak, sent it back and now the replacement is leaking after less than a full season of operation.

Nothing has really changed in the equipment the only upgrade was a set of Hayward SP1493 Quick Disconnects to make disconnecting the pump easier for winter storage. I installed them with the original Superpump and the pressure reading on the filter was exactly as it was before and flow through the returns felt similar, I can clearly see the flex PVC is not obstructed.

I'm guessing on 3 things.

1. I have a mesh cover and always open to zero CYA so I begin the slam targeting 10ppm with liquid bleach the first night of opening. I then switch to dichlor to add some CYA quickly, I adjust the pH up before adding dichlor whenever the FC drops low enough to accurately test and finally back to liquid bleach (after CYA should be 10-15) . Perhaps the 10ppm FC or slightly above with zero CYA is too potent and is damaging the seal somehow?
   
   
2. I have a DE filter so it clogs up fast perhaps when the pressure rises either it blows out the seal or the slow moving water is not enough to adequately cool the shaft seal. (my starting clean PSI is about 12@3000rpm and the highest I went to was around 18 psi over the recommend 20-25% rise but nothing catastrophic. There was still decent flow through the returns and I had only left it for 1/2 an hour so it wasn't running like that for an extended amount of time.
   
   
3. My pump is placed on top of a board that rest on 2 pavers it doesn't seem to vibrate much which would put more stress on the bearings and shaft. When hooking up the nose seems ever so slight lower than the union perhaps this slight angel is putting undo pressure on the seals between the engine and the pot.

Here is a link to a post I made about this last year it has some pics of the equipment pad and perhaps some other info I missed 2 Leaking pumps?

Pool Numbers so far
pH readings were all between 7.2 - 7.6 (regent is in date)
TA start was 80 now probably closer to 95-100 because of washing soda added to raise pH between dichlor additions
CYA was zero to start should be 10-15 now after adding 80oz of dichlor.

Thanks for any help you can give me.

 

[Texas Splash]

So these are new pump seals that are leaking correct? You didn't change the seals yourself.

 

[JamesW]

Do you ever use tabs?

Maybe chlorine tab damage or pump running dry or maybe the seals are not installed correctly.

 

[mas985]

I have a mesh cover and always open to zero CYA so I begin the slam targeting 10ppm with liquid bleach the first night of opening. I then switch to dichlor to add some CYA quickly, I adjust the pH up before adding dichlor whenever the FC drops low enough to accurately test and finally back to liquid bleach (after CYA should be 10-15) . Perhaps the 10ppm FC or slightly above with zero CYA is too potent and is damaging the seal somehow?

How are you adding the dichlor? If by skimmer, that could be an issue.

I have a DE filter so it clogs up fast perhaps when the pressure rises either it blows out the seal or the slow moving water is not enough to adequately cool the shaft seal. (my starting clean PSI is about 12@3000rpm and the highest I went to was around 18 psi over the recommend 20-25% rise but nothing catastrophic. There was still decent flow through the returns and I had only left it for 1/2 an hour so it wasn't running like that for an extended amount of time.

The pressure is not high enough to blow out a seal and as long as there is some flow rate, there should not be a build up of heat.

My pump is placed on top of a board that rest on 2 pavers it doesn't seem to vibrate much which would put more stress on the bearings and shaft. When hooking up the nose seems ever so slight lower than the union perhaps this slight angel is putting undo pressure on the seals between the engine and the pot.

Vibration could be an issue but it would have to be significant so you should be able to see it and/or feel it.

But if two brand new pumps are leaking out of the box, then it could be a manufacturing run that went bad.

 

[uloset]

So these are new pump seals that are leaking correct? You didn't change the seals yourself.

Yes both brand new Superflo VS's the first blew basically right out of the box last year the other is less than a year old. The shafts seals were both factory installed.

Do you ever use tabs?

Maybe chlorine tab damage or pump running dry or maybe the seals are not installed correctly.

I do use tabs from time to time but only in floaters. I have never had the pump run dry. I do have a small elusive suction side leak that turns up from time to time (this predates the new pumps), but it only makes a small bulb of air at the pump lid even with a filter ready for backwashing and the pump running at a low rpm. It can lead to the pump needing to prime at each startup, but the pot is still filled and primes very quickly. The hardest prime is the first of the year, but it usually starts with a trickle and takes less the a minute to fully prime.

How are you adding the dichlor? If by skimmer, that could be an issue

I add dichlor by distributing it in the deep end and then brushing.




Thanks for your everyone's help