Double Shower Screen
Has anyone heard of a "double shower screen"? Seen a few sites and parts diagrams that have this as an option.
Basically looks like a bigger showerscreen. One website refers to it as a "double delivery shower screen".
With the following description:
Double Shower Screen for E-61 Grouphead,
Called by the Italian manufactured “Doccetta Doppia”
it is designed for those application in which the puck appears always wet even when all other condition and variables are addressed.
Wondering if anyone has heard or used these before.
Looks like they would displace some of the available volume in the Filter Basket. I guess you'd probably have to grab one and do some side-by-side tests...
Maybe for trying to extract crema from cheap/stale coffee?
Yeah, i might order it and report back with some results. Maybe its the solution to using a single filter basket.
I doubt it's possible to have a "puck which appears wet when all other variables are addressed".
Did you end up ordering one?
Yep - seen it as an option years ago for La Cimbali's. Strangely enough, it is standard on the much CS maligned Sunbeam 6910 / 7000. Theoretically two screens provides a more even water pressure (considering their pressure is pretty even anyway, I do not know if it is necessary in a SB).
Originally Posted by jjjones
Nothing to do with a wet puck - IF you dial the thing in properly, the only "wet through puck" should be if the pump does not shut off quickly enough. FWIW, The 7000 has a separate thin layer of water on top of the puck as the pump restarts briefly at a (very) low pressure after the shot is pulled. AFAIAC, that just helps keep the coffee grounds out of the gap between the two showerscreens so it needs a lot less cleaning than any other machine I have lived with.
Single basket - Now you have me thinking... My 80's 2 group La Pavoni has never been very good at singles (their own, Synesso or VST baskets), however it does brilliant (for the time) doubles* - which is why I bought it for home use "way back" despite the need for plumbing and 15A power. The 6910 or 7000 does superb VST singles. Perhaps that is the difference even though I always regarded it as a quirk.
Originally Posted by jjjones
brilliant doubles* - We did a lot of blind tests with half a dozen machines a while back. The La Pav and the 6910 were equal on doubles but the 6910 was way better on singles (equal or better than all the tested "mostly commercial" machines). Considering the La Pav is a large twin boiler with a rotary pump and no PID or inbuilt preinfusion whilst the 6910 is using oversized thermoblocks with a vibe pump, PID and several preinfusion options I thought it may have been somewhere in those factors. We even turned the 9610 preinfusion off for some tests and used the same "flick the switch" manual tinkering instead and the difference on singles remained. I thought it may have been to do with the faster startup of a rotary pump. Now you have got me wondering!
It is too late to photo the dual SS setup tonight, if you are curious, please PM me and I will post it in this thread. Looks very similar to your photos except both showerscreens fit into the seal's ridges (and are fastened at the centre by a screw, just like most machines).
Spaziales also use a double shower screen, the upper one is relatively flat, the lower one slightly smaller in diameter and slightly domed to leave a gap between them.