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gbrower
07-02-2015, 06:13 AM
What life span are you getting out of your pump seals? My kettle pump averages about 75 brews but sometimes I can get almost 200. I have an internal Thompson #4. I know it would be best if I had an external pump seal but Iím not sure if it would be worth the money to switch it out. Is there something I might be doing wrong on the install? All of my other Thompson pump seals have lasted so long I couldnít tell you the last time I switched them out but our kettle pump is once a month like clockwork.

liammckenna
07-02-2015, 07:49 AM
What life span are you getting out of your pump seals? My kettle pump averages about 75 brews but sometimes I can get almost 200. I have an internal Thompson #4. I know it would be best if I had an external pump seal but Iím not sure if it would be worth the money to switch it out. Is there something I might be doing wrong on the install? All of my other Thompson pump seals have lasted so long I couldnít tell you the last time I switched them out but our kettle pump is once a month like clockwork.

Upgrade to silicon or tungsten carbide?

Pax.

Liam

Sauce
07-02-2015, 08:51 AM
We had the same problem. We were told (might of been here or through Thomsen) to try a external seal. These require a small stream of water to cool the seal. Seems to be working, though with the water bath on the seal its hard to tell (no gooey wort residue). We do try to change it out every 6 months, which is a PITA because the pumps on our mid 90's Specific Mech system are a bitch to work on. Also, I rely on our employees to remember to turn on the water for the seal, I REALLY need to get a solenoid on the water line wired into the pump switch.

TGTimm
07-02-2015, 09:10 AM
Pumps moving wort need to have washed seals. The hot wort destroys seals rapidly otherwise. Our C104 for our vorlauff/transfer pump ate its seal in a few weeks. I installed a rinser for the new seal and it's been doing fine for many years.

You need an external seal with a cold-water rinse.

Starcat
07-02-2015, 10:28 AM
I have never seen that model of pump so I don't have a picture of what you might be facing seal wise.
We are running a Waukesha C-216 on the Kettle. This design utilizes a Carbon mechanical seal that contacts the Stainless back plate.
It can go 2 or more years with zero problems if its set up right. Once the initial setup is done, subsequent seal changes are quick.
Also they are brutal in the way they run that one, but it keeps on going.
We run the same brand for the CIP carts. Those seals tend to go quicker being exposed to caustic every time they run, but will easily last a year or more.
IN the case of these pumps and I would suspect others, there is an art to setting them up and in the case of Waukesha it does not all line up with what their DOCs say.
I don't have a lot to compare to but these pumps are RUGGED on the whole.
If your seal setup is golden I would be looking in short order for something more reliable.
If you go with Waukesha I can pass on all my Tek.

Sincerely

TGTimm
07-02-2015, 02:01 PM
As I mentioned, washed seals last nearly forever under pretty rough usage. I just looked at the date on the spare seal I keep for the WC-B C104 (we have three) and it's six years old--and unused. Our big Alfa-Laval CIP pumps, also with washed seals, have been running for at least eight years since I last replaced a seal.

Waukesha sells a kit for adding wash water to their C100 series pumps, but it took me a few minutes, some 1/4" soft copper pipe, a threaded bushing, and some solder to make my own.

BrewinLou
07-10-2015, 09:52 AM
Interesting. We have a mid 90s 30 bbl Spec Mech brewhouse. I was changing out the internal seal twice a year on the wort pump until I replaced the seat plate so I could install the external seal kit. So since then (several years) I have not had to replace the seal a single time. What is did change is where I throttle the hot liquor to pasteurize the HE and Transfer hosing. I used to throttle it at the end of the loop near the drain. If I do that now the pressure will over power the spring on the external seal and water will leak out. Not a problem I now throttle the water before the pump.
The interesting part is I was never told about the water cooled part. I have never put water on the external seal.
The seal plate for the pump was not that expensive maybe $150 from Thomsen.

FYI I was told by Thomsen they have no idea why Spec Mech would have installed internal on the wort side as they are not designed for that temp. External for anything above 180.

TGTimm
07-10-2015, 10:07 AM
Joel--it's easy enough to add a water wash to an external seal. All you need is some sort of tubing that can be secured to the pump frame so it dribbles water over the seal. The amount of water needed is small, just enough to maintain a constant flow over the seal.

While an external seal is not subjected to the high temperatures of an internal one, it still benefits from being washed, as the very small amounts of wort that do manage to get into the seal will crystallize and greatly shorten the lifespan of the seal. Same for caustic and other cleaners.