Water filtration system - is 3/8" tubing really necessary for rotary pump?

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jmoser
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Joined: 8 years ago

#1: Post by jmoser »

I'm getting a new rotary machine and hoping to use my old 2 cartridge water softener/carbon filter system.
I need to retest, but I'm on well water and my water is hard, but tastes good.
The old system tubing is 1/4". I know people prefer 3/8", but is it really necessary for my rotary pump? (Expobar Brewtus)
I'd like to use the fittings I have now...but obviously I don't want to be starving my pump.
thanks

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Randy G.
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#2: Post by Randy G. »

How long of a run from the filters to the machine? I ran 3/8" but I have a good fifteen or eighteen feet or so of tubing between the filter output and the espresso machine plus a few fittings including four 90 degree elbows.

While it may not be necessary, as long as you are running all this new plumbing, you could change the output fitting of the carbon filter to 3/8" and run about a 6" length of 3/8" tubing into a tee. Run 3/8" to the espresso machine off the tee, then use a 3/8" -> 1/4" reducer (or 3/8" to 1/4" and 3/8" tee) to feed the existing 1/4" system.

I have two articles on my website which document plumbing a machine in with JG parts along with the water softener from CC:
Plumbing in an Espresso Machine - Part 1
Plumbing in an Espresso Machine - Part 2

Besides better volume flow with 3/8", it also is less likely to kink when bending.
EspressoMyEspresso.com - 2000-2023 - a good run, its time is done

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JmanEspresso
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#3: Post by JmanEspresso »

Im not saying this backed up by experience with your machine, so, yeah, just wanna lead with that.

It'll probably be ok.

1 group machines, like a full size Linea, or an Elektra Sixties, or a NS Appia, with larger pumps and big boilers to fill, those definitely dont do well with the small 1/4 in feed line. But, the semi commercial machines, such as your brewtus, and others like from Quickmill, Isomac, etc, probably can get by with the 1/4in feed line.

Id personally give it a shot and see how it goes. You'll know the instant the machine turns on and pulls water. Either it will feed nicely or the pump will immediately cavitate and make a whole lotta racket. A lot of racket.. not to be confused with the weird noise a rotary pump can make when the machine is cold.


Randy makes a real solid point though. Wouldnt be too hard to just get some 3/8in tubing into the setup for the line that feeds the machine.

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cannonfodder
Team HB
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#4: Post by cannonfodder »

Yes, your need 3/8 OD (1/4 ID) tubing for a rotary pump. It is an issue of supply volume for the rotary pump. Think of it like a snorkel, you can breath through a straw but try that after a brisk walk around the block. You need the larger pipe for volume. Your supply volume will only be as good as the smallest fitting in the assembly. I run 3/8 to my machine with a half inch mains to it.
Dave Stephens

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LaMarzooka
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#5: Post by LaMarzooka »

Been running a Speedster this way since 2010 with absolutely ZERO issues despite what a few may claim. I bought a complete set of parts from CCS and a few other places to convert my 1/4 to 3/8 but then decided all that really fun water works can just wait for the dang machine to eventually move for the re-model.

Not sure if it has to do with my nearly 5 bar pressure. Using a regulator to bring down that number to just under 3 bar. I've been very happy with this recent change from full-bore line pressure from our local water supply.
Espresso or no go!

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Compass Coffee
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#6: Post by Compass Coffee »

I wonder how many people who say you need 3/8" inlet line have ever used 1/4" inlet line. I've run multiple prosumer rotary pump machines over a decade from 1/4" feed line from mains no problem: Fiorenzata Bricoletta, Vibiemme Double Domo and Quickmill Vetrano 2B. It was the same feed line from mains I'd put in for Silvia reservoir auto-fill long ago. It was already there so I tried it when I upgraded and never had an issue.

Those who speculate a commercial machine with larger boiler and/or multiple groups will have cavitation problems are wrong in my experience. I've run GS3 MP, 3 group Linea, 3 group FB80 and 3 group GB5 from Flojet which has 1/4" out to accumulator using 1/4" in AND out then after accumulator adapter for inlet to pump. Zero issues.

That said If I had existing 1/4" I'd use it. If installing new lines I'd use 3/8".
Mike McGinness

brianl
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#7: Post by brianl »

In your flojet example, it sounds like the size tubing after the accumulator would be what's important. however, I have never tried all 1/4 despite the flojet coming with the tubing.

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AssafL
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#8: Post by AssafL »

I used 9ft of 1/4. Worked great for pulling coffees, steaming and the occasional cup of tea.

When my son was born and I started using the GS3 for filling the pans for morning oatmeal - the flow (for tea water) was unimpressive and replacing the line to 3/8 was effective.

I am not sure everyone uses their espresso for porridge, though, and since we started we also use it for soups, stews and anywhere else hot water is required.
Scraping away (slowly) at the tyranny of biases and dogma.

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Compass Coffee
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#9: Post by Compass Coffee »

brianl wrote:In your flojet example, it sounds like the size tubing after the accumulator would be what's important. however, I have never tried all 1/4 despite the flojet coming with the tubing.
Agreed output size want counts. Way back when I first got the accumulator to use with Flojet at an event I put 1/4" fittings on both sides to match Flojet and already had 1/4" adapter on line feeding Bric' so tried it and worked fine this combo. First time was going to use it with 3gr again had concerns, but also worked fine.
Mike McGinness

spearfish25
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#10: Post by spearfish25 »

I specifically asked Profitec this question and they said 'no problem' with 1/4" lines. It seems like the 3/8" is best idea just evolved without great evidence at some point in history.
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