Just saw your subsequent post.. yeah, that makes sense, terminal 2 isn't used. So the P-stat is just an on/off switch and as temperature rises the circuit between C and 1 is broken and C and 2 is probably established. Maybe you can wire up terminal 2 to power a small MP3 device that plays "It's getting hot in here" or something

Here's a thread on this PSTAT. Ray, at 1.5 bar it might be as hot as the video you posted! Why that's the craziest %#*$ing thing I've seen all day...

Mine is the Sopac model 1501 in very faint numbers.



That thread says the minimum pressure of the PSTAT is 1.5 bar, higher than I would like, I think. But there is an adjustment screw on it. The adjustment direction is noted on the cap.



And there's an adjustment screw underneath it.



Doug Garrott had said this PSTAT runs at 1.5 bar and his choice would be to restore it this way. Since he had a working Prestina, I would guess that pressure's right for this machine, but only using it will tell or learning from someone else who's used it with the old PSTAT.

If I had to wager a guess, I would say the screw on the bottom either adjusts the spring pressure or may function as a pressure regulator to affect how much pressure the P-stat picks up. The dial on the top probably allows for minor trim adjustments.

Just a guess.

Let me read the thread you linked to there...

Ray

I read the thread on the P-stat. Have you thought about just buying some sort of more adjustable pressure switch?

I built a turbocharged motor some years ago and I installed a pressure switch that enabled a water injection system. It operated at 15 PSI (1 bar approx) and turned on the motor which injected water into the turbo to cool the motor, etc.

I wonder if you could find a switch that is adjustable. Or you could use a PID controller

Ray

Ah, Ray, I have a Sirai PSTAT (pressure switch) all ready to go but no 6 mm tube to hook it up! That's why I'm rigging up the old one. It'll be interesting to try the stock setup and see how it does. The threads on the bottom where you see the plumber's tape is simply the pressure fitting that connects it to the pipe. That pipe is 6 mm but is hard copper and if I try and bend it for the other use it will probably fail. So close ... but I'll see if I can make this work.

Sounds like you are close to firing this baby up!

Ray

When I said I would restore it as original I did not mean to imply this included the SOPAC vs MATER or CEME or even Sirai. I meant generally to nix the vac valve and use the original bracket. SOPAC does not adjust down much lower than 1.3 bar or so....too hot IMO.

I've installed the Sopac PSTAT in its stock configuration for now to move toward testing the machine. The only next steps I need to do before testing are to attach a new power cord and wires as seen in the teardown photos, attach the water and steam taps. Then I can fill this machine, bring it up to temperature, adjust pressure, test for leaks and tighten seals after they've had a chance to heat up.



Awhile back I got a food safe thread sealant from Stefano's Espresso Care that seals the threads but allows easy removal and reinstallation without locking it down with Loctite. This seems to be a really good product and it's supposed to replace PTFE tape and paste. It becomes firm like soft rubber very quickly and holds things in place.

orphanespresso wrote:When I said I would restore it as original I did not mean to imply this included the SOPAC vs MATER or CEME or even Sirai. I meant generally to nix the vac valve and use the original bracket. SOPAC does not adjust down much lower than 1.3 bar or so....too hot IMO.

Let me ask your guidance then. The vac valve is to allow me to start the machine on an appliance timer. If air is trapped in the system and I start it with a timer it won't come up to temperature until I release that vacuum otherwise. The way I've currently configured the vac valve and fittings the original bracket is preserved to fix the manometer in place. The vac valve and fittings attach below the manometer knuckle. To accommodate that Sirai PSTAT I've obtained a compression nut and cap but am still missing the 6 mm copper tube to connect the PSTAT with the manometer assembly. I would love to lose some of those adapters below the manometer knuckle if you have the right fittings. What do you suggest? I think I need:

One 1/4 lateral female T fitting male male female: This connects to bottom of the manometer knuckle. The lateral male fitting connects to my vac valve.

6 mm soft copper tubing: The next two parts terminate this pipe on the bottom of the T fitting.

One solder on brass end cap fitting for 6 mm OD copper tube and 1 bicone nut brass fitting 1/4" for 6 mm tube. This end connects to pipe from PSTAT to bottom of above T fitting.

I have the compression cap and solder cap fitting to connect that pipe to the Sirai.

Update: Those fittings are on the way. And Doug and Barb are now grandparents so I'll figure this out and am in good shape. Congratulations D&B!

I might look for that thread sealer as an option for attaching my Richard Penny bottomless portafilter to the Cremina handle.

I don't want to use blue loctite or anything too hard to undo.