Size of Vibiemme Domobar Super E61 restrictor?

#1: Post by **pszilard** » April 28th, 2007, 7:36 am

Can anyone tell me if the Domobar Super has a Restrictor in the group head? If so what size? Other E61 machines often have (I am told) a restrictor of 0.7 or 0.8 mm.

Thanks.

http://users.rcn.com/erics/ · #2: Post by **erics** » April 28th, 2007, 8:05 am

I believe I have read where Ian has posted that his Vibiemme has a restriction orifice in the top line from the hx to the group. This orifice is TYPICALLY somewhere between 2.0 and 3.0 mm in diameter and has zilch effect on the brew pressure but plenty of effect on the thermosyphon system.

Obviously I defer to Ian on the details.

If you do a search on these coffee forums for "thermosyphon restrictor", you will find tons of info.

#3: Post by **cannonfodder** » April 28th, 2007, 9:25 am

The VBM does have a restrictor in the top of the thermosyphon but I don't know what the orifice size is. The group idles around 200F give or take a degree. It does heat beyond that if you let it sit idle for a couple of hours.

#4: Post by **jesawdy** » April 28th, 2007, 9:53 am

pszilard wrote:Can anyone tell me if the Domobar Super has a Restrictor in the group head? If so what size? Other E61 machines often have (I am told) a restrictor of 0.7 or 0.8 mm.

Perhaps some confusion here.... if you mean the gicleur, yes it has one, as do all E61-based groups. No idea on the size, and in fact may be different in different markets or from different suppliers. Typically 0.5mm - 0.8mm. This is the orifice that slows the brew water down on its way to the preinfusion chamber. This post points out the gicleur in The E61 Group - Truth and Lies (the whole topic is worth a read).

Eric mentions a restrictor, which is another orifice located in the thermosyphon loop (the HX temperature gradient loop that heats the grouphead while idle). I found several accounts in a quick search that the Vibiemme does have a restrictor in the thermosyphon loop, no idea on size. Again, this may be different in different markets (as Jon, RegulatorJohnson, found with Expobar, no restrictor in US, restrictor in Australia, see Installing thermosyphon restrictor on expobar office pulser).

Chris Tacy also mentions the semantics of restrictor, as he understands it, also in The E61 Group - Truth and Lies:

malachi wrote:Gicleur (in essence) tunes pre-infusion.
Restrictor (in essence) tunes group temp.

April 29th, 2007, 6:29 am

Thanks Jeff, and Eric and Cannonfodder too. This forum is truly the fountain of knowledge on all things coffee

#6: Post by **cafeIKE** » April 30th, 2007, 11:21 pm

0.110in / 2.8mm is what I have here in the USA