Re: 3-way valve abomination

Michael,
Not trying to be confrontational, although that is my claim to fame.
First, let's get past the semantics. In my market and training, lever
and hydraulic are interchangeable. Indeed, all espresso machines are
of hydraulic nature by definition.
I do not liken the function of piston-driven groups with those
incorporating pumps and valves.
My first contention with your post was that, after a lenghthy and
informative discussion of what I still consider to be a minor
consideration in the big picture, you thought it necessary to clarify
everything by making a blanket statement about commercial machines
that was incorrect. All commercial machines don't have 3-way valves.
I've already mentioned several machines that have piston-oriented
groups that I have encountered (much like The Rock encounters Hulk
Hogan). Because they have been discontinued at production levels does
not mean they are not still trying to survive on the street. I
particularly dislike the machines you classify as hydraulic. I am not
particularly fond of lever machines either, because there are only a
few Dannys in the world, and they don't live here.
>From my perspective, let me explain how "non-pump" machines get dirty.
Certain daily cleaning procedures and adjustments are not carried out.
Portafilter basket soaking. Group flushing on a regular basis (I do
this with every shot when possible, but I'm not really anal). Proper
grind adjustment, much more important on piston machines.
Restriction in the coffee delivery system can be more permeative, as
there is no valve to relieve excess pressure. As gaskets wear, weak
points develop that allow back-passage of grounds first around the
group gaskets, then around the lower piston gaskets, and then wherever
they can do the most damage after that. Then there's the issue of
piston and cylinder scoring, spring and actuation lever damage, and
the inclination of the technician to condemn the machine rather than
explain why the customer is going to have get a second mortgage on the
restaurant before you can even try to find the parts.
As far as the daily cleaning procedures, that's why the espresso gods
invented fresh water, group brushes, portafilter soaking and Brawny.
Backflushing is not an option, as you say.
Most of the posts are indeed from home users, although several now use
commercial equipment. I only pull a few shots a day when I'm not
sampling, but I still backflush daily. Some days more fervently than
others. Still, your opening statement involved commercial equipment,
but I agree that on home machines that receive very moderate use would
suffer mechanically from daily backflushing. That's a whole different
subject.
I also understand replication of group failure was for experiencing it
only. I recommend that your word be taken on this. I wouldn't want
anyone's hands to look like mine. I merely suggested that occurence of
this unintentionally was due to operator error or mechanical
malfuntion.
I hope we can save the discussion of coffee reaching the valve or the
cup after depressurization for another thread.
The mindset I mentioned was specific to the lack of daily cleaning
procedures that are propagated by machine sellers here. Some trainers
specifically say not to clean the machine daily. Helps sell the
machine, I guess.
Please don't underestimate how serious my approach is to espresso
machines and everything they do.
Viability to me is defined by the owner's willingness to continue to
repair a machine whose parts are still widely sold, which machine
still produces dozens of cups daily (no matter how badly), and the
revenue generated by both the products and the repairs. That in the
end defines viability.
Personally, these would be much more viable holding a boat in one
place.
We are not as far apart as it would seem....al

On 19 Oct 2005 13:46:32 -0700, michael@xxxxxxxxxxxxxxxxxxxxxx wrote:

>All Hydraulic machines are hybrid piston machines where the primary
>piston (large diameter) simply replaces the spring. All secondary
>seals in hydraulics share the same parts with lever machines.
>
>To liken hydraulics with modern pump driven machines would be
>problematic. Hydraulic machines in the US are quite rare, actually,
>and most manufacturers have dicontinued them. I think Rancilio still
>has one and you aren't supposed to install hydraulics in California
>because they are water hogs.
>
>While hydraulic and lever machines can and do get dirty, as you have
>illustrated, they cannot be easily cleaned by the operator daily and
>cannot be backflushed ever. Because the flow of espresso back into the
>system is not as great as with traditional modern machines, you can go
>longer between cleanings before they get gunked up.
>
>Because there is no standard daily cleaning possible for lever machines
>short of simply removing the screens, I guess I am not sure what proper
>cleaning you are referring to.
>
>Most of the posts on this board are from home users pulling 4 to 6
>shots per day. Back flushing everyday is not, in my opinion, necessary
>fro these users. Commercial users should process it once or twice a
>day.
>
>The only reason I suggested not returning the lever on E61 groups to it
>resting position is to replicate the effect of a two way valve; I
>wasn't suggesting that anyone was doing anything wrong.
>
>Also, any residual coffee that drips from the portafilter as a result
>of depressurization AFTER you stop the flow isn't what you want to
>drink. That's why you stopped it when you did.
>
>I wasn't aware that I had any 'mindset' that could be an issue here.
>Then, I wasn't aware that anyone serious about espresso machines
>thought that hydraulics were even viable anymore.
>
>Who knew?
>
>Michael

.

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