Espresso! My Espresso!
Plumbing in an Espresso Machine - Part 1
April 2011
by Randy Glass - Copyright 2011 - All rights reserved

DISCLAIMER-This article is meant to document what I have done. Plumbing failures can lead to leaks and structural damage, property damage, or injury. Do not attempt to do this unless you accept all responsibility for the procedure and its consequences. By reading this article any further you accept full responsibility. I present these instructions only to document what I have done to to plumb my machine.

     Once again I have been given the opportunity to acquire (earn) a new espresso machine. For just over three years I have been using my Vibiemme Domobar Super espresso machine with good results. When I get my act together, great shots. These machines at the pointy-end of the home barista's stick are amazing. Large boilers, massive chunks of brass that make up the group, and excellent design combine to give consistency to the point that if the espresso is a problem, it's probably caused by you!
     With a great machine in the house, why would I consider changing. My espresso bar is located in the den, and there is no plumbing there. And the machine is a pour-over, so water has to be carried to the machine and the drip tray carried to the kitchen to be emptied after each session. Forget to check the reservoir at regular intervals and either the machine is cold in the morning or it shuts down in the middle of an extraction wasting a double dose of ground coffee. I hate wasting coffee.
     But wait! there's more! The new machine is... The newly updated and improved Vibiemme Double Domo PID Rotary! Jim at 1st-line along with assistance from Stefano of Espresso Care have been working for the last year or so helping to develop the third generation of teh DD machine as they have done with all the Vibiemme machines that have come to the U.S. So when Jim offered me the "DD" in trade for some work on my part I couldn't say no.
     The DD is the same exterior size as the DS, but inside it is a different story. The vibratory pump is now a commercial-sized rotary. The HX boiler is replaced by two boilers - one for steam and one for brewing. The same group as the previous models is fed by a PID-controlled brew boiler that preliminary test have shown offers superior performance and temperature stability throughout the extraction.
     But that is not what this article is about. I wanted to concentrate on the preparations I am making for the arrival of the DD. Going from pour-over to plumbed can be quite an undertaking. You start with a simple idea, but if you have ever done any plumbing you know, as Tom Slick would say, "There's no such word as simple in plumbing, Marigold!" I can only share what I am doing and if it applies in some way to you, that's great.
     I am on a well. I am on a budget. My water is hard with a good percentage of scaling minerals. I have thought about adding a reverse osmosis system, but the wasted water and the fact that I am on private well was something I didn't want to deal with. Even with a waste return pump (that pushes the wasted water back into the hot water system) would mean electrical waste and even harder water back into the pipes. I would also need to add a booster pump for efficiency, and a UV treatment cartridge would be a good idea as well. All told it would have cost quite a bit to do that. And I still would have been better served to put a small softening filter in front of all that to help the osmosis membrane last.
     So what did I decide? A simple softening system. I have a whole house, nylon mesh filter so most sediment is kept out. Since I put it on the house years ago I have not had to clean out the faucet screens. Good for the control valves on the dishwasher and the washing machine. So the softener would be a minimum of a cation filter and a carbon filter. The first is a simple ion exchange softener cartridge and the second removes off-tastes as well as protecting the machine form any escaped softening beads. There are some sophisticated systems with easy to change cartridges which have an all-in-one cartridge (carbon, particle filter, softening, etc.) but these proprietary cartridges lock you into that system and the cartridges tend to be expensive and disposable.
     I did some research, first reading through "Jim Schulman's Insanely Long Water FAQ" to make believe I could learn something about hardness and scale. I also found some interesting information on softening. One of the often-mentioned factors with these ion exchange softening systems is the sodium that is put into the water.
     At the Alpha Water Systems. I found some interesting information on Sodium. They outlined the amount of sodium that would be in a quart of water based on various levels of grains of hardness. The ratio of sodium added to grains of hardness is 7.5mg:1, so 5 grains of hardness would place about 37mg of sodium in a quart of water.
     They also gave some figures of how much sodium we intake from some foods:

  • 1 slice of white bread - 161 milligrams
  • 3/4 cup canned baked beans - 1130 milligrams
  • 1 tablespoon of catsup - 204 milligrams
  • 1 medium frankfurter - 610 milligrams
  • 1 cup of whole milk - 127 milligrams

     Common salt (sodium chloride) can be used to regenerate the softener beads, but potassium chloride can also be used. The potassium chloride is more expensive to use, but potassium, unlike sodium, is a nutritional requirement. It is reported that some communities make it unlawful to use sodium chloride in these system since the waste salt from recharging the systems ends up in the water treatment plants and in the environment. Potassium actually has some benefit to the environment.
     Many of the softening cartridges are sealed, and when they have reached the end of their useful life they are discarded. I intend to recharge mine. This would involve soaking the cartridge in a brine solution and then flushing the excess salt away. Also available are cartridges that can be opened and the beads replaced. The removed beads can be soaked in brine while fresh beads placed in the cartridge. This lessens down time. This could also prove to be more economical and less wasteful than throwing out cartridges.
     But one way or the other, the ion exchange bead systems are relatively affordable, can be recharged with salt, and are effective.
     So I shopped around and found that for $110 shipped, the softening system that Chris Coffee sells to be a darn good deal; one which I could not beat for the price. It consists of two, 10" filter housings that can take any standard 10" filter, two John Guest valves and fittings, mounting brackets, filter wrench, fifteen feet of 3/8" tubing, and both the carbon and the cation filter cartridges. It would also be easy to add cartridges in the future if I cared to.
     That was the easy part. Now it was time to design the rest of the system. Designing and assembling a plumbing system means trying to avoid creating a Rube Goldberg device.*1 Simplicity is the key. That starts with the John Guest system (Fluid System Catalog download). For the most part, these assemble by merely pushing flexible plastic tubing into threadless fittings. Here is how they work:

1 - This is the JG tubing. It comes in various diameters. For most applications as discussed here, either 1/4" or 3/8" is used. This is 3/8"
2 - The sliding collet has the stainless steel teeth molded into it. The teeth are what hold the tube from slipping out of the fitting
3 - The inside bore of the body of the fitting is tapered. As the collet slides out it is tightened around the tubing. The harder the tubing is pulled, the tighter the stainless steel teeth are pushed against the tubing.
4 - The stainless gripping teeth are in this part of the collet.
5 - This O-ring is the actual water seal. As the tubing is pushed into the fitting you will feel it stop against the O-ring. It is important to push the tubing past this O-ring.
6- The collet will slide in and out a little, but the further out it is pulled, the tighter it grips because of the tapered bore. Pushing the collet all the way in will allow the teeth to release the tubing and the tubing can then be removed from the fitting. The end of each section of flexible tubing seals by being pushed past an O-ring inside the fitting, and the tube is held in place by stainless steel teeth. No teflon tape and little to no flow restriction. A collet which is part of the fitting can later be depressed which releases the tubing so the tube can be removed whenever you desire, and the fittings are all reusable. The fittings and tubing do not scale, another benefit when plumbing hard water. There is a large range of fittings in various sizes. I choose to create a 3/8" system (instead of 1/4") because of the length of the run from the supply to the espresso machine.
     But not so simple... I also wanted to have a sink-top faucet so that I could dispense the softened water for beverage use, and I wanted to supply the ice maker in the fridge which is currently plumbed with copper.
     I worked on the design for a week, refining, simplifying, and finally drawing a plan that took into account the route the plumbing would (most likely) have to take. Here is a scan of the final plan I used to place my order:

The left third is the under-sink area in the kitchen, the middle portion is the facing wall where the fridge resides, and the other side of that same wall is the espresso bar. Some notable parts are: 14 is a one-way valve, and 1, 5, 8, and 11 are shut-off valves. The section from 15 through 7 to 10 are under the house.

I wanted to be able to shut off any single area of the system in case of a leak so there are numerous valves:
     - at the supply stop valve where the JG plumbing begins
     - at both ends of the filter system (supplied with the system)
     - on the supply line to all three ends points of the lines (the tap, the ice maker, and the espresso machine).
     Overkill? Maybe, but this way I can isolate any of the system's components. For example, if the ice maker needs to be shut off I will still have water at the espresso machine. The two included valves for the filters mean that the filters can be shut off and isolated when cartridges need to be changed. And if it all goes mammaries skywards, the "DD" has a simple valve to switch from plumbed to reservoir. And while it is a bit complicated with all those fittings, it was another reason I chose to use 3/8 inch tubing instead of 1/4 inch (be aware that the black is UV resistant. Other colors are not). The larger diameter tubing would also be less likely to kink which is a factor if I need to move the espresso machine or when I pull out the fridge for coil cleaning.
     I used the drawing to put together a shopping list, shopped around, and found some good prices on what I needed. Including the filter system, a tap for the kitchen, a replacement stop valve, and all the JG fittings, it came to a total of $220.80 delivered, so far. Regardless as to what system I installed, only half of the cost was the filter system itself, the rest was related plumbing supplies. With everything bought, I awaited the delivery of multiple parcels as well as an espresso machine.
     From all that, if you are attentive and knowledgeable, you may be wondering, "What about the drip tray?" The DD's opv and 3-way both dump into the drip tray, so that has the potential of a bit more waste water to deal with than I am accustomed to. Once the supply plumbing is done I plan on using a drain system that will empty into a gray water pit which will be dug specifically for that use alone. But for now, let's stay focused on one catastrophic undertaking at a time- the water supply.

*1 - Appropriately enough for my water article, Goldberg's father was a San Francisco police and fire commissioner, who encouraged the young Reuben to pursue a career in engineering. Rube graduated from the University of California, Berkeley in 1904 with a College of Mining degree and was hired by the city of San Francisco as an engineer for the Water and Sewers Department.