Two Londinium I pulls (water, no coffee) with the pressure gauge attached. Please ignore the squeeky wooden kitchen floor and the wobbly old refrigerator supporting the heavy plumbed-in Londinium I Luxe on its top. For the first pull I have the valve tweaked to allow about an espresso-volume of water to pass in about 30 seconds. Starting around 6 bar, the pressure relaxes as the 'extraction' progresses.
The position of the camera is static so the second pull seems immediately after the first, but in the break I have closed the valve.
For the second pull I leave the PF full of water and with the valve closed I show what maximum pressure the spring, coiled more than usual, can deliver. 8-9 bar easily, and when I lift the lever a little, even more than 11 bar.
Music from Gabe Baltazar's 1994 "Birdology" album.