La Pavoni Lever Anti Vacuum valve 2952015 (old code 396754R) can be found inside the safety valve, on the right of the boiler.
Usually found in newer machines. If you have an older machine with the Teflon valve, you need to replace the entire safety valve body in order to use new valves like this one.
When your Safety Valve is making strange sounds and does not close properly, this valve is usually the part to blame.
La Pavoni Lever Anti Vacuum valve code 396754R is used along with the Safety Valve Spring code 311407 (New Style), found here – click to view.