If you removed your OPV, you had all of the parts in your hand with the exception of the valve seat which is machined into the OPV housing (brass elbow) screwed into the boiler.

On older Silvia's (10 yrs), the valve is a round rubber pad, 11 mm OD, held in a small steel housing by a small, special machine screw. It is possible that the machined seat has some nearby scale hence the suggestion by Jim G. to run some descaler through the OPV with a blind filter in place and if you replace the valve portion of the OPV assy together with the copper washer, you will be in good shape.

Eric - thanks for the info. Here is a picture of the parts in the order I've been assembling them. The 2 metal washers are on the end that goes into the OPV housing? On top of the rubber pad?

It looks like maybe some of the rubber pad is gone. Could that be the problem?

Any chance the valve seat can be damaged?

When assembled, there aren't any leaks at the boiler connection. I am getting steam and hot water out of the return tube like I have never seen before.

I can post more detailed pictures if you require.

Marc -

This is just a GUESS but those two small stainless steel washers (acting as shims) should fit over the small end of the valve which slips into the spring. My Silvia did not have those parts but they would serve to adjust the OPV's setting.

If you remove the machined screw (can be a little tough) and CAREFULLY pop out the rubber pad, you can simply "reverse it" and have a new surface to play with. At this point I would say you could operate with/without the SS washers but come Monday I would order some new rubber pads and, most definitely, some new copper washers.

The machined seat could be damaged or have some scale nearby but that is something you could deal with after trying the above.

Well it looks like the machine is fixed and working properly again.

I re-assembled the opv without using the 2 small washers and that did the trick. Flow rate is back to around 250ml / min. and my test shots appear to be acting 'normal' again for the given dose and grind.

Thanks for the responses here, and special thanks to Jim from 1st-line who answered my private emails and helped me get this thing fixed. He even recommended simply cleaning the opv and doing the repair myself as opposed to just buying one of the new adjustable silvia opv's as I was inclined to do initially. No pressure salesmanship, just helpful advice for one of his 1st-line customers.

Hopefully everything will be fine over the next few days and this will be my last entry in this thread!

Hi,
I realize I'm late to the game on this discussion, but I'm having a similar problem with my Rancilio. I did the 'pump return' test long ago and got it in the 8.5-9 bar range (by using volume) but it seems like my pressure has been going down since I did that about 2 years ago. Anyway, since I had this helpful graph above, I tightened the nut on my OPV about 1 full turn and got the same return flow rate (about 280 ml/minute), which was exactly the same as I had before tightening the nut. I tightened another full turn and again got the same flow rate (280 ml/minute). Is there something wrong with my OPV? Maybe I over tightened (there is a mm or two of gap between the two nuts)? Could my pump just be running lower than when I first bought it?

Why not take the OPV assembly out & inspect? Certainly the "clearance" between the adjusting hex and the locking nut seem reasonable and I would say that turning the adjuster 1 full turn should have had dramatic effects on the flow.

Yes, something seems amiss. Give me a call at 301-587-5033 if you want some help.

Thanks. I'll give it a look see and see if I can see anything. I suspect I'm just handy enough to be dangerous, so I may take you up on your call offer if it isn't readily obvious to me. (PS - I can most definitely appreciate the skål sign-off. My wife is Danish, so I can't even tell you how many times I heard this salutation at our wedding and other family celebrations.)

I have Silvia v3 (a couple of months old) and the flow rate just measured is around 500ml/min with an empty portafilter (280ml in the first 30 secs). The static pressure is 10 bars. Is something wrong with the machine? Judging by the comments in this thread, that's way too high, no? Thanks.

asdf777 wrote:Judging by the comments in this thread, that's way too high, no?

Way too high? No, not really.

For a vibratory pump/OPV espresso machine, the static pressure is higher than the actual pressure while brewing, anywhere from 0.5 to 2.0 bar, with the majority of the espresso machines being on the lower side of that range. Rancilio Silvias are known for a being a bit fussy, especially if the brew pressure is high. I would lower it to 9.0 bar (static) under the assumption the actual brew pressure is 8.5 bar. If the crema production drops off dramatically, bump it up back up 0.5 bar.

If you really want to know the actual brew pressure and you're feeling industrious, it's not difficult to build your own pressure portafilter from ordinary hardware parts. Searching the forum and/or FAQs will reveal a few threads showing the membership's handiwork.

Dan, thanks for the tip on presssure! By "too high", I actually meant the flow rate: it's 500ml/min, which is twice the amount specified for 9-10 bars in the chart above.

Can the flow rate vary so dramatically from one machine to another or there is something wrong? Or maybe something has changed in v3?