No issues there as long as you have the SS braid connecting line. I would have put the gage in the front panel but that's an individual issue.

Keep in mind also that doing something like this has questionable impact on Silvia's resale value. Knowing what I know now, I would just set Silvia's OPV at 9.0 bar with a blind filter and keep it there.

Thanks.

I wouldn't do it for resale value, but more as something to do I guess, although cutting through the face doesn't sound like a great job.

erics wrote:Knowing what I know now, I would just set Silvia's OPV at 9.0 bar with a blind filter and keep it there.

What is it that you know now that has changed what you did in terms of installing a gauge? Just that it isn't necessary?

That's correct - in my opinion, it is not necessary. There's probably about a dozen or so other issues that will improve shot production with continuous monitoring of brew pressure being way down on the list. "Way down" that is, once it is set to a value that the end user desires via a good gage connected to a blind filter.

A Rancilio Silvia can be as simple or as complex as one wants to make it and surely there are examples of that on the forums. I'm a big fan of modifications (hopefully improvements) that can be done to machines which improve their ability to produce more consistent espresso but that are also easily reversible.

I believe that if Silvia's OPV is set such that blind filter pressure is 9.0 bar, the resultant pressure during a typical shot will be "just right" - i.e. in the region of 8.5-8.6 bar.

although cutting through the face doesn't sound like a great job.

I fitted mine round the side at the back of my Silvia. It is easy enough to access and use on a day to day basis without cluttering up the front of the machine. It also makes fitting easier.
I used a gauge with a max. pressure of 300psi - approx double the expected range. This was at the recommendation of the gauge supplier.
Photos showing the process of fitting the pressure gauge including a full list of parts and suppliers are here
http://www.flickr.com/photos/robives/sets/72157612560672607/

I helped my friend fit a gauge to his Silvia last summer (2008).
In this case we used a 1 1/2" diameter, silicone filled, 11bar/160psi, stainless gauge purchased from McMaster-Carr (catalog number 9780T21).
Link to McMaster-Carr: http://www.mcmaster.com/#9780t21/=2big51
We used 1/4" diameter plastic tubing and 1/4" brass compression fittings to connect the gauge into the high pressure output line from the pump. Cutting the hole in the face plate was accomplished by removing the faceplate and clamping it to a drill press table and then use a metal-cutting hole saw.

The silicone fluid damps the pump vibration effectively and overall it works very nicely.

Thanks, paperpig. I more or less modified my Silvia for a pressure gauge like you did. I did find a source of supplies that made things both easier, and less expensive:http://shop.hoseandfittings.com/catalog/Fitting/Brass/Push_to_Connect.html I elected to use their push to connect and so far am using the Nylon pressure pipe, since none of this is in the hot zone. Item 50210 for example allow you to cut about 2 cm of the teflon pipe (mine does not have the metal jacket) and simply slides in, and gave me 1/4" NPT for an output. Then there are pushconnects so that a connector can be screwed onto the gauge and you then simply slide the hose in.

SO-here's my problem that needs a troubleshoot. I did this because my PID'd silvia has been making me unhappy. I find that when I turn on the hot water, the pressure climbs up to 10 bar. But if I fire up the coffee valve, the same gauge shows no pressure. The pump is running either way. I certainly get water under pressure out of the group head. This can't be the OPV, and the pump is running. WHAT don't I understand?

Erics' idea of a temporary mans of reading the brew pressure--what would it take to scerw a pressure gauge fitting into the pipe in place of the steam nozzle? With the needle valve open, I wonder how much pressure drop there is.

Silvia's steam wand has M5 x 0.80 female threading - keep in mind this is a 10 yr old Silvia and things MAY have changed. It can be done but would be relatively expensive because of the adaptor to go from the M5 threading to a pressure gage. A good PF pressure gage is perfectly adequate and, in addition, is always transferable to other machines.

If you simply activate the hot water switch, the group solenoid valve remains closed and you are simply reading the same pressure you would read when using a blind filter. Adjust your 10 down to 9 and you may be happier.

When you simply pump flushing water through the group, there is pressure at the pump discharge but it is essentially zilch - maybe 0.1 bar or less.