So I'm plumbing my LR to use an external reservoir and bypass the internal pump. I have everything put together now but am having some issues with the pressure regulator.

My system is an external pump, accumulator, a Watts 560 regulator with pressure gauge, a downstream pressure gauge, and a shut off valve downstream of those.

The pump/accumulator is set to output 90 PSI/6 bar.

What I'm trying to do is figure out how to set the pressure downstream of the regulator to 4 bar.

If the shutoff valve is closed, both pressure gauges read 90 psi. If I open the valve then I think that's when I should be able to read downstream pressure, but I have the regulator bottomed out (adjustment screwed all the way in) and I'm getting about 50 psi. I can get it higher than that I think but it doesn't seem linear. There is a point where the system shutters within that adjustment range and I don't know what that's about.

So I guess my question is how do you properly calibrate a regulator for use behind an espresso machine? In my case that downstream pressure will be my preinfusion pressure so I want to be able to adjust it and have some feedback. Ie should the shutoff valve be closed to build max pressure, wide open to allow full flow, or somewhere in the middle?

Pics

Have a slow trickle running somewhere down-stream, perhaps that downstream shut-off valve in a sink just barely not closed so that there's a trickle letting the downstream pressure out to the "set point" and you can get a constant reading of what that set point is.

I'm not totally certain I understand what your question is. "Tightening" the pressure regulator, screwing the knob in, righty-tighty, is tightening the spring against the spool that stops the inlet, thus it takes a higher downstream pressure to stop the flow, thus the downstream pressure is higher. With the regulator "un-screwed", lefty-loosey, there's almost no pressure delivered by the spring on the valve so even a slight downstream pressure will shut the valve and prevent the downstream pressure from getting higher.

For pre-infusion purposes, you might like approximately 2 to 2.2 bar (30 - 35 PSI).

I think I'm probably not understanding things very well. It seems my max pressure at the second gauge is about 50PSI unless the downstream valve is shut. I have it now connected to the LR. When the adjustment knob is all the way tightened as far as it will go gets me that 50 PSI, if I back it off halfway or so then it drops the pressure down to 15 PSI or so. Seems to me I should be able to get 90 PSI to 0PSI after the regulator since that's the pressure (90 PSI) before the regulator. I imagine there's a bit of loss in the regulator but I'd think not that much.

I'll do more reading...

I have a different regulator, but what looks like the same pump/accumulator (Shurflo) hooked up to my Compressa.



For my regulator, turning adjustment screw clockwise causes the regulated output pressure to increase. As I turn to increase, both the regulator output pressure (on regulator) and filter output gauge will increase as I go. However I'll need to flush the group briefly to read the new lower pressure after turning counterclockwise to reduce pressure. Note that you can't read pressure accurately with water flowing.

I put a gauge after the filter so I could see any drop across filter while pulling a shot; this would indicate filter getting clogged. Normally they read the same. It's not clear to me why you installed a gauge after the regulator - both of your gauges are reading the pressure on the same piece of tubing.

Some things to check:
- input/output on regulator properly connected (I.e. not reversed)
- adjust regulator to some mid point and see if you can incrementally raise/lower pressure
- did you initially charge the bladder on the accumulator as per instructions? On my Shurflo it says to pump to 50psi when tank is empty
- did you notice the pump fill the accumulator at first or after some use? What is the pressure in the tank after it stops filling? You can check the air-inlet you used to pump the bladder (or just put a gauge before the regulator). For a 90psi system you should read close to 90psi, but this will reduce as you pull water from tank.

Thanks CoffeeMac, you got me in the right direction - I had the regulator reversed. Now things are working as expected!

I have a couple of those WATTS 560's...you have to look closely (or read the spec sheet) to see the directional flow arrow.... If it's hooked up backwards it won't work...BTW I think these Watts regulators (in the correct pressure range for espresso machines) are more solidly built than the plastic bodied ones. Just my opinion.

Totally correct, I had to look *REALLY* close to see the arrow, and even then had to confirm with a magnifying glass that it was an arrow and not a scratch! But now that I have it in the proper orientation it works as expected and I can dial in my desired pressure quickly and easily. And as CoffeeMac said I can now take out the second gauge, they both read the same and that's one less thing to leak in the chain.

Thanks everyone!