Assemble a pressure gauge to check your espresso machines group pressure.

[Tex]

Building your own portafilter-mounted pressure gauge.

Parts
* portafilter with single 3/8" spout fitting
* liquid-filled pressure gauge, 150 - 200 psi (1/8 or 1/4 NPT fitting)
* 3/8" NPT brass FIPS elbow ("L")
* 3/8 x 1/8 (or 3/8 x 1/4, depending on gauge's fitting size) NPT brass reducing fitting (aka pipe bushing)
* Teflon pipe tape

Wrap the outside threads of the pipe bushing and gauge with a double layer of Teflon pipe tape. Insert the pipe bushing into the "L" fitting and tighten securely. Thread the gauge into the pipe bushing and hand tighten only, leaving the gauge in a horizontal position to the upright "L".

Now wrap the threaded spout fitting on the portafilter with a double layer of Teflon tape, and thread the "L' onto the PF (hand tight). The gauge must be in a horizontal position for the "L' to be fitted to the portafilter. After the "L" is secured to the PF, turn the gauge to a readable angle.

Adjust the OPV until you get a reading on the gauge of 145 psi (10 bar). This is a static setting that corresponds to 130 psi (9 bar) dynamic pressure - considered to be the ideal pressure for making espresso.

[bobvilax2000]

I made one of those a few years ago. I was annoyed when WLL updated the Brewt with a brew gauge so I remedied it. Later when I upgraded the pump I needed one. Very handy.

- -Barrett

[Tex]

I source the parts at a local hardware store (O'Day Rental & Hardware in Pearland, TX) for ~$16. Pre-made ones usually cost ~$59 - that's a lot of green beans!

[mp]

I source the parts at a local hardware store (O'Day Rental & Hardware in Pearland, TX) for ~$16. Pre-made ones usually cost ~$59 - that's a lot of green beans!

Hmm Robert ... maybe you could offer pre built ones for the ones who dare not venture there.

 

[Ascholten]

the liquid filled gauge i am guessing is for dampening so it doesn't bounce around too much.

make sure the liquid is glycerine or other food grade material.

IF you can't find one then get a shut off valve, another few dollars and you can crack it just about all the way shut to throttle to the gauge to stop the oscillations.  We do that on air compressors all the time to dampen out the pulsations.

Aaron

[John F]

the liquid filled gauge i am guessing is for dampening so it doesn't bounce around too much.

I added a permanent gauge to my machine and the first one was not liquid filled... needle bounced like crazy. I added a bunch of cooper loops to dampen the flutter and it worked sort of ok but there was still some flutter.  I switched it out for liquid filled and it as smooth as glass....... Zero flutter.

[milowebailey]

the liquid filled gauge i am guessing is for dampening so it doesn't bounce around too much.

I added a permanent gauge to my machine and the first one was not liquid filled... needle bounced like crazy. I added a bunch of cooper loops to dampen the flutter and it worked sort of ok but there was still some flutter.  I switched it out for liquid filled and it as smooth as glass....... Zero flutter.

How expensive are the gauges?  Less than $16?

[John F]

How expensive are the gauges?  Less than $16?

Depends on what you want but I saw tons of them around $20.

[Tex]

How expensive are the gauges?  Less than $16?

Next time you're in Houston we'll go to O'Day - they have liquid filled gauges for ~$15. It's just down the street from Central Texas BBQ, so we can kill two birds...


BTW: I've worked on 2 - 3 dozen commercial HX espresso machines in the past few years and I've yet to find a single one with accurate pressure gauges (boiler & group pressure). That's the primary reason I recommend PIDing a HX machine; not for temp stability but just to have an accurate idea of what's going on.

That & a portafilter-mounted pressure gauge renders the fancy dual gauges redundant.

[Ascholten]

with an oscillating load / bellows pump type pump etc that i believe an espresso machine will have, yes the gauge will bounce like mad.  The liquid gauges work nice because the liquid is nice and thick like glycerine, so it takes a lot to move the gauge, ... well actually the pressure is there but the dampening effect of the liquid makes the needle move slowly so those quick pop pops get smoothed in.... if you can not get a liquid gauge, think of a needle valve or just a cutout / shutoff valve put between the boiler and gauge.  you close it almost closed, in other words with the pump running you work it closed until the bouncing of the needle is almost negligible (ie you dampen it out)....  another nice feature of a cut out valve is, sooner or later that gauge will give out and start pissing it's innards all over, you just close the valve completely until you can  procure a new gauge and your pot is not out of service the whole time.,

Aaron

[SusanJoM]

Here's the one I put together a couple of years ago for testing the Gaggia.   It's the same one that I loan out to members of the Gaggia User's Group when they want to test/adjust the pressure at the brew group.

Susan

[mp]

Wow ... nice work Susan!

 

[SusanJoM]

Wow ... nice work Susan!

 

I had a good teacher....

Susan