I was thinking about making a pressure reading portafilter, then I thought why not add a gauge to my Silvia?

Ideally I'd like to mount it on the front, just not sure until I get home to look at it if there is enough room. Alternatively it could be mounted inside the machine under the top cover. Perhaps even a hole in the cover that goes around the gauge leaving it visible.

My first thought is to connect it between the boiler and the OPV as this would allow measurement of brew pressure as well as steam pressure.

Am I missing something or would it be as simple as I am thinking?

Kurt

It is difficult because of the close quarters you are working in and the various fittings can become a nightmare. See here and look at the pictures in the folder "silvia undressed":

http://users.rcn.com/erics/

The easiest place to temporarily read the brew pressure (while brewing) is where the steam line attaches to the boiler. The fitting on the boiler is 1/4-19 BSPP and a normal US pipe thread fitting is 1/4-18. With a little teflon tape on the boiler's threads and the use of brass fittings, it will seal.

If you wanted to do something more permanent, Chris Coffee sells a pressure gage cap tube setup:

http://www.chriscoffee.com/produc...arts/capillarytube

I believe these have 1/8-28 BSPP threads vice the US standard of 1/8-27 and you would need to tee into the steam line and adapt from there. Going between the boiler and OPV, you are faced with the prospect of undoing those fittings where the teflon line connects and reassembly can be iffy depending on machine age and other factors. In addition, there is not enough play in the teflon line to do what you want.

The most non-intrusive & easy solution is the PF gage and, if you build one, use a liquid filled gage.

Eric S.

Actually, that is exactly what I was thinking of with the gauge below the power switch.
I'm not afraid of replumbing the machine as need be. Where did you tap into for the gauge?


It was interesting to note that your counter is the same as mine. My wife noticed that your wall color looks pretty close to ours as well. Maybe it's a Maryland thing...

Kurt

It is beastly hard to cut through that stainless, and harder to make it look good.

Yes, it must be a Maryland thing.

I replaced the original OPV with an Expobar OPV attached to the pump and adapted into the original OPV housing. The long term value is questionable but the tinkering sure was fun. Cutting the hole in the stainless really needs to be done in a drill press and that was not fun.

BSPP adaptors are available from a variety of sources:

http://mdmetric.com/

http://www.hoseandfittings.com

http://www.swagelok.com/

Eric S.

If you really want a brew gauge, go for it, but they aren't must-have items. I installed an external gauge on La Valentina and I only check it every few months to make sure the pump and OPV are healthy, which could easily be done with a portafilter gauge.

That said, after some arduous searching, I refound How do you install a pressure gauge on a Rancilio Silvia? on CoffeeGeek. It has lots of good suggestions and links, including Pepe's PID front mounting detailing the fun of making holes in stainless steel.

Eric,
I was thinking about Swagelok as they have always had what I needed and there's a distributor near my home. I didn't know about MDMetrics, which is near my work. Thanks.
As far as the hole goes a metal punch will make short work of it and give a clean hole.

HB,
I know the gauge isn't a must-have, but I like to tinker and customize. It's kind of like making a street rod
Besides, the cost is about the same either way.

Kurt

OK, I should have caught on from the "old442" tag. I have very fond memories of a '65.

The girls and guys (and I say that very affectionately) at Swagelok (Washington Valve & Fitting) know me very well so use my name - Eric Svendson. I go up there every other week to pick up goodies for my thermocouple adaptor and because I simply enjoy that town.

If you want, let me know when you are going to start this adventure - erics@erols.com and 301-587-5033

But you really need to plan this task out or suffer the effects of espresso withdrawal

Eric

This Swagelok thing has caught my interest (as do most tinkering projects). Are there any write-ups, part numbers, install docs available? I'd like to find out more about this.

Thanks,
George

erics wrote:OK, I should have caught on from the "old442" tag. I have very fond memories of a '65.

The girls and guys (and I say that very affectionately) at Swagelok (Washington Valve & Fitting) know me very well so use my name - Eric Svendson. I go up there every other week to pick up goodies for my thermocouple adaptor and because I simply enjoy that town.

If you want, let me know when you are going to start this adventure - erics@erols.com and 301-587-5033

But you really need to plan this task out or suffer the effects of espresso withdrawal

Eric

Washington Valve and Fitting Rocks, and fyi John Bevaqua is a motorhead. They all know me pretty well there as one of the crazies from the National Institute of Slow Thinkers.

In answer to the following post (I'm clairvoyant, huh?) http://www.swagelok.com is a good place to look at fittings. For our purposes the regular Swagelok compression fittings are more than adequate. Buy them in 316 stainless steel. Silvia plumbing is 6mm diameter, and Swagelok carries metric sizes as well as US. If your local distributor is as good as Washington Valve and fitting you'll get what you need quickly, and lots of help besides.

-Greg