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RE Acres
03-22-2018, 02:45 PM
Hi everyone,
Banging my head against the wall and though maybe someone might have some ideas.

I have a horizontal CDL electric releaser with a Goulds 1 HP pump, that I have had for 5 seasons and had been working flawless up to 27".

This year it only wants to pump if I drop the vacuum down to about 10" otherwise it just cavitates.

I have replaced the leaking check valve and thought I was golden. Nope then I removed the pump front cover after talking to the CDL rep. He said that sometimes shavings from installing saddles in the pipeline get caught in the impeller. He was right, the intake of the impeller had plenty of pipeline shavings. Thought the problem was solved, but my issue remains.

The last interesting items is that I have no air bubbles in the extractor coming form the pump until the pump runs for a a while and then air is introduced somewhere and the pump cavitation starts until I reduce the vacuum.

I need to get this fixed before the sap really starts to flow. Any and all thoughts would be appreciated

Tom

mellondome
03-22-2018, 04:29 PM
Sounds like this is an external pump? If so, do you have a line plumbed into vac somewhere between the pump and the checkvalve?

RE Acres
03-22-2018, 09:20 PM
Yes this is an external pump with a small return line to the releaser

mellondome
03-23-2018, 12:13 AM
The return line is masking the vacuum. You still have a vac leak, probably inside the pump since it doesnt push any liquid.

OneLegJohn
03-23-2018, 05:51 AM
Yes, I had the same thing happen this year. I took over a Woods with that type of setup in two pump stations. Instead of trying to make an outdated setup work (it was tempting) we picked up one of those Leader/BHR electric releasers with the integrated deep well pump. There is definitely a leak taking the prime from your pump. If you have to limp by, you could try dropping the level of your pump, too.

We installed (6) of those BHR electric releases with integrated internal pumps this year. We have one more of the electric releaser/external pump setups. It seems to be working but I don't know how it will do long-term. Wish I had better news for you. But this sounds exactly like the battle I was fighting.

The comment above reminds me. Goulds pumps were designed to run under ambient air pulling from a tank. I've been warned that high vacuum, like you have, will eventually damage the pump seals. So, this could be a good example if you have every fitting sealed up and still lose prime. Maybe the pump seals are leaking by?

BAP
03-23-2018, 06:05 AM
I would check the shaft seal. After 5 years of use it could be worn or ripped.

maple flats
03-23-2018, 07:28 AM
While I don't have any experience with electric releasers, I have been told you can pump a vacuum tank by having a small vacuum line on the pressure side of a pump to make it so that pump is in a vacuum environment. I wonder if you add a 5/16 vacuum line just out past the pump if that would solve the problem. It was suggested to me years ago but I never tried it, that was before 3/16 came around, maybe even a 3/16 vacuum line might work. I didn't try it because I didn't want to risk having my pump freeze and also because I wash the tank after each time I pump it out and for that I need to shut off the vacuum to the tank anyway.
As I say, this might be a way to get it to pump.

GeneralStark
03-23-2018, 07:58 AM
If I am reading this correctly, you are using an electric releaser with an external Goulds shallow well jet pump. If that is the case it is quite possible that as others mentioned, your pump's seals are worn so it can not handle the vac. level you want to be at. While these pumps will work in this application there is a reason releaser manufacturers have shifted to deep-well submersible pumps placed inside the releaser chamber...

RE Acres
03-26-2018, 11:42 AM
Thanks for the replies everyone. It's beginning to look like the only thing left is the shaft seal. I will update when I know more.

Mark
03-26-2018, 01:52 PM
Thanks for the replies everyone. It's beginning to look like the only thing left is the shaft seal. I will update when I know more.

10k55 seal

RE Acres
04-09-2018, 09:14 AM
Hi everyone,
Thanks for the input. The issue was resolved by replacing the shaft mechanical seal behind the impeller. In theory the impeller unscrews quite easily to access the seal, but I found that 5 years of sap makes pretty good lock-tite. A little heat to the shaft and impeller with a propane torch was enough to crack it loose.

Any other year this would have been a nightmare, but winter will not end in Wisconsin. Season is normally ending about now, but it has been so cold that that I have had next to no sap in the last 10 days and barely enough sap so far to use my RO 3 days total for the season. Should be interesting to see how the season ends