Is OPV on Giotto Classic and Premium the same?

Need help with equipment usage or want to share your latest discovery?

#1: Post by ristrettobrain »

I decided it was time to order a pump pressure check kit and see where the OPV is set on my ECM Giotto Classic. I just looked at the recent OPV thread (part pasted below) and am wondering if the Giotto Classic uses the same OPV as Premium, which is referenced below.

I will add another post asking for pressure limit recommendations.
HB wrote: Thanks for the pictures, that helps a lot. The silicone tubing leading away from the vibration pump looks like an overflow. See the fixture encircled in red below:

I am hoping this is a shim-type adjustment expansion valve similar to the Giotto Premium's:

If so, the adjustment instructions I offered in Help Me Adjust Overpressure Valve on a Giotto Premium apply to your machine too, i.e., give the slotted shim a turn outward (CCW) to allow more water to escape (lower overall pressure) or inward (CW) to increase the spring tension and allow less water to escape (higher overall pressure). Keep in mind however that since you have a vibration pump, this will only affect the maximum pressure when pulling ristrettos. In other words, the actual brew pressure is the lesser of the puck's resistance, the pump's capacity at a given flow rate, and the expansion valve setting.

PS: No need to apologize and please don't hesitate to ask for help again. Cross-posting is one of those netiquette issues that isn't universally accepted; my reminder was primarily to avoid several people investing time answering the same question, that's all.

User avatar

#2: Post by HB »

Yes, to the best of my knowledge, the Classic and Premium have the same OPV. Also see the thread Testing Brew Pressure, which includes instructions and pictures. Below is a closeup:

Dan Kehn