Louis wrote:Since I've got the S1 Vivaldi, I found myself using the hot water tap a lot more than what I was expecting (can provide as much as 1L), even if I understand that a $2000 machine is not to be used as a $10 kettle, that I will get more scale as more water is going through the steam boiler, etc. Instant hot water is practical and this is simply hard to ignore.
The only issue I have is that the process is very inefficient: ~110°C water coming out as some 100°C hot water along with a lot of steam. The water is also too hot for our main use: green tea. We cool it off to 75-80°C (~175°F) by moving it through two different vessels before infusion. Wasted electricity to heat water; wasted electricity for the air-conditioner to cool down the excess heat.
I'm considering the addition of a hot water mixing valve to my Vivaldi to cool water to a more reasonable / practical temperature. The machine is plumbed-in and uses a solenoid valve for hot water. It uses plastic tubing, which seems ideal to do the mod (provided I can get the correct parts and fittings).
- Any idea where I could procure the correct parts?: connector to the S1 plastic tubing (out of steam boiler, back to hot water solenoid), Y between cool water mains and F-o-T pump inlet, inter-parts connections between the additional parts, check valves, Y, etc.
- Any worries to keep in mind to avoid a big mess (I'm already protected by an automatic mains shut-off in case of water leaks) or equipment damage?
Does anyone have answers to these questions?Louis wrote:I found a GB/5 mixing valve at espresso parts.com ($21).
The part listed by espresso parts is shown on page 35 (part 13).
It (part 13) gets cold water from a tee (bottom) on the steam boiler refill line, and outputs (through a check valve, part 12) to another tee (part 10), which mixes this regulated amount of cold water at pump pressure (9 bar from outside pump) with water(/steam?) coming from the steam boiler (from right of part 10, again through a check valve (page 37). The third outlet of the tee (part 10) is then going directly to the hot water solenoid (part 8 ), before ending in the hot water tap.
I've got the rest correctly set up:
Thinking again about the pressure differential issue, I have:
1. cold water from mains, regulated at ~2.5 bar (35 psi)
2. hot water from steam boiler, at 1-1.35 bar (1.35 at set temp, 1 bar when steam valve is opened)
3. hot water tap at 0 bar
It then seems like a "water mix valve", set at the correct opening, will deliver just enough cold water to the mixing tee to cool down the steam boiler water (~110°C to 75-100°C).
Now that I understand the setup in theory, where do I start with to actually do something?
- Where can I find in parts catalog the type/thread pitch/size of fittings used? How do I know different parts I would order online will fit together? All parts catalog I've looked at don't say a word on this.
- If I want to put everything together using plastic (teflon?) tubing, what kind of fittings will be required?
- Can I simply assume parts/fittings from LaSpaziale could fit with parts from LaMarzocco (thread pitch, size)? (Wouldn't that be great!)
- Where can I get all these parts? Any repair shop? (Chris Coffee for LS? Espresso parts for LM?) Do they usually carry every part? (My order would be a mix of heteroclite parts).
- What is special about the mixing valve? Is it pressure regulated? If I buy this one made for a LM under 9 bar of pressure, would I need to be really lucky for it to fit under 2.5 bar with different water tubing sizes?
It is frustrating as this really seems to me like a good idea, I now know how to do it, but I have no idea where/what to procure to make it happen…