The S1 Cafe - Helping Your Espresso Dreams Become Reality

So I wasn't really sure where to put this post so I put it here because it has to do with my tear down and build up.

I bought an Orman 60mm dual pressure gauge from Cafeparts.com, part number 49398. I liked the look of it over the many other options I had. It has the standard 1/8 BSP fittings on the back so below is how I have it hooked up. I did not have the boiler on because of a boiler fill blocking error that I need to get figured out. So far the gauge works great! I’m not sure how it will work in the long run since the tube is hooked up in the group head and coffee grounds could possibly get up there during backflushes and the pressure release.

The 60mm gauge should fit into a 2 3/8" hole but I have not drilled it to confirm. I measured the gauge with a caliper and the body was just under 2 3/8" so it should be fine. I will need to mount it from the front, which will obviously make removing the front very annoying, but oh well. The capillary tubes are quite long so hopefully I can pull off the front sometimes and not need to remove the tubes. If I need to remove the tubes, oh well, I guess it may be a good time to empty the tube if it is having issues. I was hoping to find a gauge with an easily removable bezel but nothing jumped out at me. I am also not sure how well it will fit:) When I hold the panel up I can tell that I cannot drill the new hole any lower than the current hole because it will hit the flowmeter piping. I think I can drill the new hole using the bottom of the current hole and increase it upwards but I still may need to bend some piping. Details:)

Brew Pressure:
-Removed the 1/8 BSP plug on the left side of the group head.
-Bought a 1/8 BSP male to male adapter, Cafeparts #67490
-Bought a capillary tube from Chris' Coffee, which is 1/8 BSP
-Hoooked the capillary tube to the adapter with PTFE tape on both ends.
-Hooked the other end of the capillary tube to the gauge with some PTFE tape.

Boiler pressure:
-Bought a 1/4 BSP female to 1/8 BSP male adapter, Cafeparts #50421
-Bought a capillary tube from Chris’ Coffee
-Attached the adapter with some PTFE tape to the same port on the boiler for the old gauge.
-Attached the capillary tube to the adapter with some PTFE tape.
-Attached the capillary tube to the gauge with some PTFE tape.

https://vimeo.com/166027306

It would appear that I have a very high group pressure, according to section 8.3 of the manual. I wasn't sure if a backflush shows the same pressure as an espresso shot but I guess it does. Since I want to accurately test it I guess I should back it off to 8.5 bar for now and then readjust it when I get it in the permanent location with a regulator in line.

It looked like your group pressure is going up to 14psi. The expansion valve is supposed to be set to start opening at 12psi. If that is set correctly you should never see 14psi on your meter. While the pressure is that high it's a good time to reset the expansion valve, then you can lower the pump pressure down where you want it.

Hmm, I saw that and it didn't quite process apparently, since I was literally just looking at the expansion valve adjustment procedure! Thanks for pointing that out, I was thinking of tearing it apart anyway but now I will definitely take a look since I need to adjust it anyway.

So I opened and cleaned my expansion valve over the weekend and it didn't look too bad. I put it back together and adjusted it to start dripping at 12.5 bar or so. For anyone wondering it is very easy to take the expansion valve apart and put it back together. The spring is stiff but it isn't hard to push it on and then start tightening it on.

So I installed a pressure regulator and dropped it down to about 50 and I noticed a couple of things.

-The backflushing pressure was reduced to to 10 bar and the needle on the gauge was a little bouncy. It was rock solid at the higher pressure. This must mean that I do not have a balanced valve in the pump or the higher inlet pressure was not letting it work appropriately.

I have not adjusted the pump pressure because I want to get the inlet water flow and pressure straightened out.

So I finally put my machine back together and have it drawing from a water container. I adjusted the pump to 8.5 BAR and the needle is steady. I think the bouncing needed was probably air in the lines because I was testing it so much and draining the water out of the line, and losing the prime of the pump. I will post some pictures later but I really like the gauge. It was a tight fit though, and it will not be fun taking the panel off to service anything, because the gauge is attached from the back to the front panel. The capillary tubes are pretty long though so it is at least possible to do it without taking the panels off:)

Updated with a video. I just liked the cascading effect, similar to a Guinness:) (You need to watch it in full screen and HD for the best viewing.)

https://vimeo.com/172575308