Machine Design Question- proposal

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Date: 21 Jun 2006 13:21:15
From: Randy G.
Subject: Machine Design Question- proposal

Backflushing has been a topic of interest here. I was just writing an
addition to the conclusion of my "3-way" pages and the thought came to
me. What level of safety is designed into an espresso machine- Silvia
specifically?

In Silvia, the pressure relief bypass is set for +/-9BAR (130PSI). A
Ukla is stated to be able to develop about 15BAR (217PSI). Whether one
could achieve that in any reasonable amount of time is questionable,
but still...

SCENARIO: The pressure relief valve has failed, stuck in the closed,
non-functioning position from a bit of loose brass from the machining
process (these have been seen in the 3-way valve, so the scenario is
not totally impossible, but highly unlikely.. still...). A person
pulls a shot with too-fine of a grind. The brew switch is turned on
and the person waits for about 20-30 seconds to see if anything will
come from the spouts.

Q1: What pressure will the pump reach during that time assuming
+/-120volts?
Q2: Can the machine take that pressure for that amount of time without
damage?
Q3: Is the machine designed to handle the maximum amount of pressure
the Ukla pump can develop? that is, did the engineers foresee this
possibility and design around it?
Q4: How long before the thermal safety in the pump circuit stops the
pump?
Q5: What is the maximum amount of pressure the machine can handle?
Q6: What is the weakest part of the machine- i.e.- what part would/is
most likely to fail first as the pressure is increased?

My guess is that the weakest part is the plastic line between the pump
and the boiler and its related fittings would fail first. Either the
line would burst or it would pop out of a fitting, but that's just a
guess. I also guess that it is capable of handling around 225-250 PSI
or more.

If someone has a Silvia they want to send me I would be glad to head
over to the science dept of the local college for some
semi-destructive testing.

Randy "science as opposed to the other" G.
http://www.EspressoMyEspresso.com

Date: 21 Jun 2006 14:54:23
From: daveb
Subject: Re: Machine Design Question- proposal

A:

I have been asked any number of times to add a washer to silvias in the
shop -- to the OPV to reduce the press. Is it really too high?
Someone has a measurement somewhere...

bottom line -- would it deliver a better cup?

Dave

sprsso wrote:
> I don't know that I would take it that far, but a machine that does
> not offer some facile way to remove burnt on oils and grounds would be
> one to avoid. I'd be interested to know what the bar rating on the
> Silvia group valve is. In case it hasn't been discussed recently, bar
> ratings on valves are important for a number of reasons....al
>
>
> >
> >My personal thoughts are that a machine with a 3-way that the
> >manufacturer states cannot take backflushing is not properly designed
> >and not worth buying.
> >
> >
> > Randy "just did yesterday" G.
> >http://www.EspressoMyEspresso.com
> >
> >

Date: 21 Jun 2006 22:17:38
From: sprsso
Subject: Re: Machine Design Question- proposal

You know, I've been asked this question a number of times and still
don't have a definitive answer. The machines I have worked on with
vibratory pumps have had no pressure relief valves to ameliorate pump
pressure at the group. The properly designed machines have delivery
systems to make sure that the energy from the pump is properly
expended by the coffee in the portafilter. The delivery to the coffee
cake is regulated by distribution tubes, gicleurs and mixing tubes
designed to regulate temperature distribution from the exchanger to
the final contact of the coffee.
Not knowing the Silvia, I would say that rather than shunt the
pressure, as I think it does, delivery should be designed to optimize
the presentation to the cake.
I couldn't say for sure that simply reducing the group delivery
pressure would offer a better cup. Wish I could....al

On 21 Jun 2006 14:54:23 -0700, "daveb" <davebobblane@gmail.com > wrote:

>A:
>
>I have been asked any number of times to add a washer to silvias in the
>shop -- to the OPV to reduce the press. Is it really too high?
>Someone has a measurement somewhere...
>
>bottom line -- would it deliver a better cup?
>
>Dave
>
>
>sprsso wrote:
>> I don't know that I would take it that far, but a machine that does
>> not offer some facile way to remove burnt on oils and grounds would be
>> one to avoid. I'd be interested to know what the bar rating on the
>> Silvia group valve is. In case it hasn't been discussed recently, bar
>> ratings on valves are important for a number of reasons....al
>>
>>
>> >
>> >My personal thoughts are that a machine with a 3-way that the
>> >manufacturer states cannot take backflushing is not properly designed
>> >and not worth buying.
>> >
>> >
>> > Randy "just did yesterday" G.
>> >http://www.EspressoMyEspresso.com
>> >
>> >

Date: 21 Jun 2006 17:45:42
From: Ken Fox
Subject: Re: Machine Design Question- proposal

"sprsso" <acritzer@cfl.rr.com > wrote in message
news:cjgj92daskhtovphjbnqjh8s7guc5inv36@4ax.com...
> You know, I've been asked this question a number of times and still
> don't have a definitive answer. The machines I have worked on with
> vibratory pumps have had no pressure relief valves to ameliorate pump
> pressure at the group. The properly designed machines have delivery
> systems to make sure that the energy from the pump is properly
> expended by the coffee in the portafilter. The delivery to the coffee
> cake is regulated by distribution tubes, gicleurs and mixing tubes
> designed to regulate temperature distribution from the exchanger to
> the final contact of the coffee.
> Not knowing the Silvia, I would say that rather than shunt the
> pressure, as I think it does, delivery should be designed to optimize
> the presentation to the cake.
> I couldn't say for sure that simply reducing the group delivery
> pressure would offer a better cup. Wish I could....al
>

Sorry, I fired a blank before typing my comment.

Cimbali Junior Vibratory pump models for a number of years have had pressure
relief valves incorporated within them. My 10 year old vibe pourover has
one, and while visiting Bravo (the BC Canada Cimbali importer and dealer)
recently, I purchased a spare, which was of a newer design (and made of SS
instead of brass) to the one in my machine. While there I had a chance to
see an older design OPV than the one in my machine; my impression is that
these OPVs in various designs have been on Cimbali vibe pump machines (or at
least the juniors) for more than 20 years.

In the stock configuration as they were shipped to N. America, the pourovers
(at least) had the OPV set in a way that they were not used; no water was
bypassed and full, un damped vibe pump pressure was delivered to the
espresso puck. I measured 14-15 bar on my machine with a PF manometer
before the OPV was set to vent the excess water back into the pourover tank.
This was done with the assistance of Jim Schulman on his first or second
visit, when he noticed the OPV, told me what it was, and that if we hooked
up a piece of silicone tubing to the "nipple" on the valve the valve could
be set to bypass water to the pourover tank to regulate the extraction
pressure. We did this to good effect however at a later time the OPV
started to make a terrible screeching noise, which I was only able to
correct by custom fabricating a new gasket since Pasquini told me that the
replacement gaskets weren't for sale and I'd have to pay $70 to replace the
OPV. Bravo actually stocked the gaskets and I did buy several on my recent
trip, however the new ones screech as well. This is after descaling of the
valve and repeated attempts to sand down any irregularities on the valve
"seat" on the inside of the valve, however my homemade gasket continues to
work fine as it seats a little higher on the valve surface since it is
thicker. Replacing the spring in the valve also did not resolve the
screeching sound.

The techs at Bravo told me that it is harder to adjust the OPV on the old
plumbed in vibe S Juniors as they have to have the overflow going down the
drain; they often can't get the valves set to better than 10 bar, whereas
I've had no problem setting my pourover's valve at about 9 bar, measured on
either of my two PF manometers.

What I"m getting at is that Cimbali vibe machines that ng readers might own
probably can have their output pressure successfully regulated, at least to
10 bar, which should be an improvement over 14 or 15 bar. In blind taste
testing with Jim Schulman, a couple of years ago and again this past March,
we judged the shot quality from the 10 year old regulated vibe pourover as
at least equal to that obtained from my 3 year old Rotary Junior which is
regulated to 9 bar as well. The vibe machine is also much more forgiving of
minor barista errors in dosing/distribution/ and packing when compared to
the unmodified rotary machine. By design, vibe pumps have slow pressure
ramp ups, which is a bit like preinfusion on a rotary machine designed to
have it (the rotary Junior does NOT have preinfusion in the stock
configuration).

ken

Date: 21 Jun 2006 17:49:11
From: Ken Fox
Subject: Re: Machine Design Question- proposal

"Ken Fox" <morceaudemerdeThisMerdeGoes@hotmail.com > wrote in message
news:4fu413F1khs3tU1@individual.net...
>
> The techs at Bravo told me that it is harder to adjust the OPV on the old
> plumbed in vibe S Juniors as they have to have the overflow going down the
> drain; they often can't get the valves set to better than 10 bar, whereas
> I've had no problem setting my pourover's valve at about 9 bar, measured
> on either of my two PF manometers.
>

typo: I meant "vibe D Juniors" above

Date: 21 Jun 2006 17:26:08
From: Ken Fox
Subject: Re: Machine Design Question- proposal

Date: 21 Jun 2006 14:42:22
From: daveb
Subject: Re: Machine Design Question- proposal

<< . . . a machine with a 3-way that the manufacturer states cannot
take backflushing is not properly designed and not worth buying. >>

Then the Silvia is not worth buying, rg. Because that is EXACTLY what
Rancilio says.

[That statement from Rancilio and the very same statements from any
number of major sellers, i.e. Sweet Marias are dismissed by rg and fx
and bobbyboy as 'Ah, they are just trying to avoid liability lawsuits']

and on and on.....

Thanks Al for your valued input..

Dave "byuytb456rh6bvse" b

Randy G. wrote:
> sprsso <acritzer@cfl.rr.com> wrote:
>
> Thanks, al. I was hoping I would get an answer from you...
>
> >Anyone with any knowledge of the machine should never wait 20-30
> >seconds for drops to start appearing. I haven't read your backflushing
> >guide, but I hope you advise not running the pump for more than a few
> >seconds, not past the "lock out" sound.
> >
> I specifically state that the time to leave the pump running is two or
> maybe three seconds at the most. My most recvent page states:
>
> Q: What do you mean when you say not to leave the pump running when
> backflushing for an "extended period"?
> A: Since it only takes about two or maybe three seconds at the most
> for the pump to reach all the pressure it possibly can achieve when
> backflushing, then I would say that an "extended period" would be
> defined as, "More than about three seconds."
>
> My personal thoughts are that a machine with a 3-way that the
> manufacturer states cannot take backflushing is not properly designed
> and not worth buying.
>
>
> Randy "just did yesterday" G.
> http://www.EspressoMyEspresso.com

Date: 21 Jun 2006 22:23:38
From: I->Ian
Subject: Re: Machine Design Question- proposal

On 21 Jun 2006 14:42:22 -0700, "daveb" <davebobblane@gmail.com > wrote:

><< . . . a machine with a 3-way that the manufacturer states cannot
>take backflushing is not properly designed and not worth buying. >>
>
>
>Then the Silvia is not worth buying, rg. Because that is EXACTLY what
>Rancilio says.
>
>[That statement from Rancilio and the very same statements from any
>number of major sellers, i.e. Sweet Marias are dismissed by rg and fx
>and bobbyboy as 'Ah, they are just trying to avoid liability lawsuits']

Review the Silvia manual at
http://www.espressotec.com/manual/RancilioSilviaManual.pdf
and find nothing for or against backflushing.

One can find recommendations to backflush after every shot, albeit
with plain water, at Chris Coffee
http://www.chriscoffee.com/faq#5
all the way to never...

Anecdotal evidence such as "I always backflush and my XYZesso has
lasted for 10 years without a fault" is suspect, just as is "Joe
doesn't backflush his eXpreXXo machine and it died in 6 months"
because Joe may have commited a multitude of other sins :

There are so many variables, like water hardness, grind, tamp,
immediately remove PF and rinse or let PF and puck bake in the group
head, descale frequency, etc. that unless one set up a robotic line
with several machines to make thousands of expresso, half backflushed
and the other not, until they fail and then cut the machines apart, it
appears this topic falls in the IMNSHO category.

Does anyone have any science to support their claims?

Date: 21 Jun 2006 17:00:20
From: Randy G.
Subject: Re: Machine Design Question- proposal

"I- >Ian" <someone@nowhere.com> wrote:
>
>Review the Silvia manual at
>http://www.espressotec.com/manual/RancilioSilviaManual.pdf
>and find nothing for or against backflushing.
>

Let's look at this from a 'legal' standpoint. The manual does not
state whether you should or shouldn't backflush.

Would backflushing, if done properly, void the warranty?

-It is not abuse if done correctly
-It could even be said that it is a health issue, that it must be done
to keep the machine clean and sanitary internally.
-Not backflushing COULD be considered neglect since it would allow a
build up of material in the machine that could cause it to
malfunction. Neglect voids the warranty.

AFAIK, what Rancilio "recommends" or "states" means nothing as far as
the warranty is concerned, at least in the U.S. Warranties must be in
writing, no? Since backflushing is a fairly universal cleaning chore
as far as espresso machines with 3-way valves are concerned, it
couldn't be considered abusive to the machine if done correctly-
again, no more so than choking the machine.

And as I asked before (somewhat rhetorically) without receiving a
reply or comment, I will repeat myself: If the machine malfunctions
because the 3-way valve became clogged from coffee debris, will
Rancilio cover the warranty costs, and since their "unofficial"
statements seem to indicate that backflushing would void the warranty,
and not backflushing could be considered "legislated neglect," will
they pick up the repair costs and shipping when (IF) it happens?

The entire point is that it is counter-intuitive to think that ANY
company would require you to neglect their machine under warranty. Not
backflushing a machine to remove build up of coffee oils and grounds
which could lead to a malfunction is, by definition, neglect.

Randy "use only official Rancilio toilet paper" G.
http://www.EspressoMyEspresso.com

Date: 21 Jun 2006 14:37:27
From: daveb
Subject: Re: Machine Design Question- proposal

ON and on . . . .

BTW -- I have NEVER seen the teflon plastic line burst -- in over 100
Silvias, new or old -- not a guess.

dave "bhufgyun677cfmtu6" B

Randy G. wrote:
> Backflushing has been a topic of interest here. I was just writing an
> addition to the conclusion of my "3-way" pages and the thought came to
> me. What level of safety is designed into an espresso machine- Silvia
> specifically?
>
> In Silvia, the pressure relief bypass is set for +/-9BAR (130PSI). A
> Ukla is stated to be able to develop about 15BAR (217PSI). Whether one
> could achieve that in any reasonable amount of time is questionable,
> but still...
>
> SCENARIO: The pressure relief valve has failed, stuck in the closed,
> non-functioning position from a bit of loose brass from the machining
> process (these have been seen in the 3-way valve, so the scenario is
> not totally impossible, but highly unlikely.. still...). A person
> pulls a shot with too-fine of a grind. The brew switch is turned on
> and the person waits for about 20-30 seconds to see if anything will
> come from the spouts.
>
> Q1: What pressure will the pump reach during that time assuming
> +/-120volts?
> Q2: Can the machine take that pressure for that amount of time without
> damage?
> Q3: Is the machine designed to handle the maximum amount of pressure
> the Ukla pump can develop? that is, did the engineers foresee this
> possibility and design around it?
> Q4: How long before the thermal safety in the pump circuit stops the
> pump?
> Q5: What is the maximum amount of pressure the machine can handle?
> Q6: What is the weakest part of the machine- i.e.- what part would/is
> most likely to fail first as the pressure is increased?
>
> My guess is that the weakest part is the plastic line between the pump
> and the boiler and its related fittings would fail first. Either the
> line would burst or it would pop out of a fitting, but that's just a
> guess. I also guess that it is capable of handling around 225-250 PSI
> or more.
>
> If someone has a Silvia they want to send me I would be glad to head
> over to the science dept of the local college for some
> semi-destructive testing.
>
>
> Randy "science as opposed to the other" G.
> http://www.EspressoMyEspresso.com

Date: 21 Jun 2006 20:46:53
From: sprsso
Subject: Re: Machine Design Question- proposal

Some good questions here.
I don't work on home machines, and have only seen one Silvia in
person, but I can answer some of the more generic questions.
The pump will reach its full pressure capacity within a few seconds.
You can tell by the sound when it "locks out". I know this having
worked on the Unic Phoenix for years, which has a vibratory pump. They
developed 15+ bars rapidly. This was using a closed portafilter guage
to set the expension valves to break at 15bar.
Most group valves in lower-priced machines are rated at 15bar, usually
printed right on the coil, so a fully energized pump with nowhere else
to go would just blow past the valve.
The thermal safety for the pump would probably take minutes to disable
the pump.
Anyone with any knowledge of the machine should never wait 20-30
seconds for drops to start appearing. I haven't read your backflushing
guide, but I hope you advise not running the pump for more than a few
seconds, not past the "lock out" sound.
I don't know what kind of tubing and fittings are incorporated into
this machine, but if you are advocating backflushing, they are
designed to withstand the full pump pressure. It also depends on
whether they were built right after lunch or on Friday.
And, for what it's worth, I have seen expansion valves disabled by
debris on dozens of occasions, so it's not highly unlikely.....al
On Wed, 21 Jun 2006 13:21:15 -0700, Randy G. <frcn@DESPAMMOcncnet.com >
wrote:

>Backflushing has been a topic of interest here. I was just writing an
>addition to the conclusion of my "3-way" pages and the thought came to
>me. What level of safety is designed into an espresso machine- Silvia
>specifically?
>
>In Silvia, the pressure relief bypass is set for +/-9BAR (130PSI). A
>Ukla is stated to be able to develop about 15BAR (217PSI). Whether one
>could achieve that in any reasonable amount of time is questionable,
>but still...
>
>SCENARIO: The pressure relief valve has failed, stuck in the closed,
>non-functioning position from a bit of loose brass from the machining
>process (these have been seen in the 3-way valve, so the scenario is
>not totally impossible, but highly unlikely.. still...). A person
>pulls a shot with too-fine of a grind. The brew switch is turned on
>and the person waits for about 20-30 seconds to see if anything will
>come from the spouts.
>
>Q1: What pressure will the pump reach during that time assuming
>+/-120volts?
>Q2: Can the machine take that pressure for that amount of time without
>damage?
>Q3: Is the machine designed to handle the maximum amount of pressure
>the Ukla pump can develop? that is, did the engineers foresee this
>possibility and design around it?
>Q4: How long before the thermal safety in the pump circuit stops the
>pump?
>Q5: What is the maximum amount of pressure the machine can handle?
>Q6: What is the weakest part of the machine- i.e.- what part would/is
>most likely to fail first as the pressure is increased?
>
>My guess is that the weakest part is the plastic line between the pump
>and the boiler and its related fittings would fail first. Either the
>line would burst or it would pop out of a fitting, but that's just a
>guess. I also guess that it is capable of handling around 225-250 PSI
>or more.
>
>If someone has a Silvia they want to send me I would be glad to head
>over to the science dept of the local college for some
>semi-destructive testing.
>
>
> Randy "science as opposed to the other" G.
> http://www.EspressoMyEspresso.com
>
>

Date: 21 Jun 2006 13:58:30
From: Randy G.
Subject: Re: Machine Design Question- proposal

sprsso <acritzer@cfl.rr.com > wrote:

Thanks, al. I was hoping I would get an answer from you...

>Anyone with any knowledge of the machine should never wait 20-30
>seconds for drops to start appearing. I haven't read your backflushing
>guide, but I hope you advise not running the pump for more than a few
>seconds, not past the "lock out" sound.
>
I specifically state that the time to leave the pump running is two or
maybe three seconds at the most. My most recvent page states:

Q: What do you mean when you say not to leave the pump running when
backflushing for an "extended period"?
A: Since it only takes about two or maybe three seconds at the most
for the pump to reach all the pressure it possibly can achieve when
backflushing, then I would say that an "extended period" would be
defined as, "More than about three seconds."

My personal thoughts are that a machine with a 3-way that the
manufacturer states cannot take backflushing is not properly designed
and not worth buying.

Randy "just did yesterday" G.
http://www.EspressoMyEspresso.com

Date: 21 Jun 2006 21:47:46
From: sprsso
Subject: Re: Machine Design Question- proposal

I don't know that I would take it that far, but a machine that does
not offer some facile way to remove burnt on oils and grounds would be
one to avoid. I'd be interested to know what the bar rating on the
Silvia group valve is. In case it hasn't been discussed recently, bar
ratings on valves are important for a number of reasons....al

>
>My personal thoughts are that a machine with a 3-way that the
>manufacturer states cannot take backflushing is not properly designed
>and not worth buying.
>
>
> Randy "just did yesterday" G.
>http://www.EspressoMyEspresso.com
>
>

Date: 21 Jun 2006 16:32:24
From: Randy G.
Subject: Re: Machine Design Question- proposal

sprsso <acritzer@cfl.rr.com > wrote:

>I don't know that I would take it that far, but a machine that does
>not offer some facile way to remove burnt on oils and grounds would be
>one to avoid.
>
That is what I meant. Backflushing seems the easiest way to clean
those passages, but there are other solutions such as an access
drilling(s) covered with a plug(s). The point was that if there are
areas that get that dirty that can't be accessed, or can't (shouldn't
be backflushed) then the machine should not be purchased in favor of a
one better designed.

I was just contacted by a Silvia user who had not been backflushing,
avoiding that chore in compliance with the reseller's warranty
statements, in fear of voiding the warranty. After reading my pages on
the subject and my in-depth discussion of the operation of the 3-way
valve he decided to backflush (shhh!). He jury-rigged a blind filter
and using just water (no cleaner) he stated that crud was still coming
out after ten of fifteen 'flushes.' If plain water removed that much
junk, it had to be tainting his coffee if not jeopardizing the
correct function of the machine.

Although he had been keeping the machine maintained by regular
cleaning of the shower screen and descaling, he stated that a LOT of
crud was removed from the machine when he backflushed. No real
surprise there.

Other than the possible water-hammer effect (minimized by the
operation of the OP valve), I still believe that choking a machine is
no diffeent from backflushing in regards to this subject. The machine
doesn't know whether it is a too-fine puck of a blind filter in there.

Randy "appreciates al's opinions and knowledge" G.
http://www.EspressoMyEspresso.com

Date: 21 Jun 2006 23:55:03
From: sprsso
Subject: Re: Machine Design Question- proposal

I agree that the machine doesn't know the difference. That having been
said, backflushing does have a negative effect on the pump and the
delivery system. Many of my customers use pods, so the recommendation
is a backflush once a week and an abreviated one at that. Backflushing
reduces valve life and pump life. Whether the advantages outweigh the
detriments remains to be seen.
I still recommend a daily backflush for my busier clients. Please
explain the water=hammer reference....al
>
>Other than the possible water-hammer effect (minimized by the
>operation of the OP valve), I still believe that choking a machine is
>no diffeent from backflushing in regards to this subject. The machine
>doesn't know whether it is a too-fine puck of a blind filter in there.
>
> Randy "appreciates al's opinions and knowledge" G.
>http://www.EspressoMyEspresso.com
>
>

Date: 21 Jun 2006 18:13:49
From: Randy G.
Subject: Re: Machine Design Question- proposal

sprsso <acritzer@cfl.rr.com > wrote:

> Please
>explain the water=hammer reference....al
>

Water hammer (it's what we called it when firefighting) is the sudden
impact of a flow of water with nothing to absorb the force. You can
hear it in the pipes in your house when the filler valve in the ice
maker, washing machine, or diswasher closes and suddenly stops the
flow of water. When firefighting we learned (the easy way) that when
closing a fire hydrant to the flow (like when filling a water tender)
that you need to close the valve slowly. Clamping it shut too quickly
can cause a downstream effect that will damage plumbing in surrounding
houses that are connected to the same system. It is also why opening
it slowly is important to avoid blowing out hoses.

In the espresso machine, when backflushing, it happens when using a
blind filter. For the first backflush the PF is fairly empty and there
is some air trapped in the brewhead behind the basket/blind filter.
This air has to be compressed and that does a good job of cushioning
the rush of water from the pump. When the pump is turned off, a bit of
that water and air will be evacuated into the drip tray, but the
volume of air in there is now diminished, and becomes somewhat less as
this is repeated. The next on rush of water ramps the water pressure
more steeply than the first becasue the cushioning pocket of air is
smaller in volume and the water will bang the OPV open with more
force.

I don't think the difference is too great, and I am not sure it really
has any adverse effect on the machine, but it does exist, so I try to
mention it.

And in the inverse of your situation, I only know a little about
commercial machines, so my comments are only accurate when talking
about home machnes like Silvia.

Randy "knowledge is good. It's a shame it isn't universal." G.
http://www.EspressoMyEspresso.com
GO USA! Gooooooaaaaaaaaaaaaaaaallllllllllllllllllllllllllllllllll!!!

Date: 22 Jun 2006 17:47:39
From: I->Ian
Subject: Re: Machine Design Question- proposal

> Randy "knowledge is good. It's a shame it isn't universal." G.
> http://www.EspressoMyEspresso.com
>GO USA! Gooooooaaaaaaaaaaaaaaaallllllllllllllllllllllllllllllllll!!!
>
>

OT : The USA played like they already had 6 points in hand. Fairly
obvious after 15 minutes that they were out of WC '06

Date: 22 Jun 2006 11:34:03
From: GeeDubb
Subject: Re: Machine Design Question- proposal

"I- >Ian" <someone@nowhere.com> wrote in message
news:mqll92dpn3f3nplkk5mfqah731mbcobkfa@4ax.com...
>> Randy "knowledge is good. It's a shame it isn't universal." G.
>> http://www.EspressoMyEspresso.com
>>GO USA! Gooooooaaaaaaaaaaaaaaaallllllllllllllllllllllllllllllllll!!!
>>
>>
>
> OT : The USA played like they already had 6 points in hand. Fairly
> obvious after 15 minutes that they were out of WC '06

that's because they don't drink the right coffee....

Gary (sort of back on topic)

Date: 21 Jun 2006 18:16:16
From: Ken Fox
Subject: Re: Machine Design Question- proposal

"sprsso" <acritzer@cfl.rr.com > wrote in message
news:3fmj925ueppbrnkld79lci9j6lh92apq9i@4ax.com...
>I agree that the machine doesn't know the difference. That having been
> said, backflushing does have a negative effect on the pump and the
> delivery system. Many of my customers use pods, so the recommendation
> is a backflush once a week and an abreviated one at that. Backflushing
> reduces valve life and pump life. Whether the advantages outweigh the
> detriments remains to be seen.
> I still recommend a daily backflush for my busier clients. Please
> explain the water=hammer reference....al
>>

Solenoid valves are not terribly expensive and generally one must only
replace the solenoid itself (the insides) and not the coil. One must of
course stay with the same brand and model, they are not interchangable.
Vibe pumps are also cheap. The 42 watt Ulka which was original equipment in
my pourover Cimbali Junior lasted for 10 years, with 7 of those years being
in daily operation, mostly on 24/7. I backflushed 2 or 3 times daily with
water and repeatedly once a week for a chemical backflush. The machine is
on its 3rd solenoid, with the current one having been put in a couple of
months ago (e.g. I got an average of 3.5 years out of each solenoid with
daily use and frequent backflushing). Solenoids and vibe pumps are parts
that a semi capable home enthusiast should be able to replace themselves in
their own machine, with minimal or no help from the dealer.

I can't comment on the impact of backflushing on rotary pumps other than to
say I've done the same backflushing routine on my rotary machine for 3.25
years and it is on its original rotary pump. Rotary pump replacements are
available and if I needed to replace mine in another year I would regard it
as having given good service and that would be that.

I'm not a tech and I don't pretend to be, nor can I state that everyone
would have the sort of luck I've had with these parts, nor whether this
would be true of different machines. The solenoid and the pump were however
pretty much the same as you'd see in most home machines.

I'd rather have a clean machine which needed a new valve every 3+ years and
a new pump every 7 then have the parts last longer and be concerned about
the cleanliness of the machine.

ken

Date: 21 Jun 2006 22:17:42
From: Coffee for Connoisseurs
Subject: Re: Machine Design Question- proposal

The o/p valves on the Silvias seem to be set at 10 - 11 bar ex factory.
Latest model valves are adjustable, short article with pics to follow next
month.

--
Alan

alanfrew@coffeeco.com.au
www.coffeeco.com.au

Date: 21 Jun 2006 18:42:10
From: Craig Andrews
Subject: Re: Machine Design Question- proposal

"Coffee for Connoisseurs" <alanfrew@coffeeco.com.au > wrote in message
news:aAjmg.13959$ap3.9980@news-server.bigpond.net.au...
> The o/p valves on the Silvias seem to be set at 10 - 11 bar ex
> factory.
> Latest model valves are adjustable, short article with pics to follow
> next
> month.
>
>
> --
> Alan
>
> alanfrew@coffeeco.com.au
> www.coffeeco.com.au
>
>

And why the washer OPV mod is set to between 8.5 - 9 bar & is said to
deliver a sweeter shot. Pressure mod here:
http://mysite.wanadoo-members.co.uk/m4tt5mith/SilviaPressureMod.html
Craig.

Date: 21 Jun 2006 22:19:27
From: sprsso
Subject: Re: Machine Design Question- proposal

Alan,
Hey Buddy, how are you?
Do you know what the bar ratings on the solenoid valves are?....al

On Wed, 21 Jun 2006 22:17:42 GMT, "Coffee for Connoisseurs"
<alanfrew@coffeeco.com.au > wrote:

>The o/p valves on the Silvias seem to be set at 10 - 11 bar ex factory.
>Latest model valves are adjustable, short article with pics to follow next
>month.

Date: 22 Jun 2006 11:22:36
From: Coffee for Connoisseurs
Subject: Re: Machine Design Question- proposal

Hi Al, hope you & Karen are well, I'm in the middle of a server upgrade,
hair not just white but vanishing! Don't know what pressure the solenoid
opens at but it's a "standard" assembly, widely available in the industry,
and not exclusive to Rancilio.

--
Alan

alanfrew@coffeeco.com.au
www.coffeeco.com.au
"sprsso" <acritzer@cfl.rr.com > wrote in message
news:pchj92p6lid9bo06lhnfhkikivtarn7n8n@4ax.com...
>
>
> Alan,
> Hey Buddy, how are you?
> Do you know what the bar ratings on the solenoid valves are?....al
>
> On Wed, 21 Jun 2006 22:17:42 GMT, "Coffee for Connoisseurs"
> <alanfrew@coffeeco.com.au> wrote:
>
>>The o/p valves on the Silvias seem to be set at 10 - 11 bar ex factory.
>>Latest model valves are adjustable, short article with pics to follow next
>>month.
>

Date: 25 Jun 2006 18:27:03
From: RBeech
Subject: Re: Machine Design Question- proposal

On Wed, 21 Jun 2006 15:17:42 -0700, Coffee for Connoisseurs
<alanfrew@coffeeco.com.au > wrote:

> The o/p valves on the Silvias seem to be set at 10 - 11 bar ex factory.
> Latest model valves are adjustable, short article with pics to follow
> next
> month.
>
>
> --
> Alan

Alan -

Do you mean that new Silvias are coming with an adjustable OPV? Will this
be retrofittable to the older models if so?

This could be worth waiting for...

R

Date: 25 Jun 2006 21:59:32
From: Coffee for Connoisseurs
Subject: Re: Machine Design Question- proposal

>Do you mean that new Silvias are coming with an adjustable OPV? Will this
>be retrofittable to the older models if so?

Yes and yes.

--
Alan

alanfrew@coffeeco.com.au
www.coffeeco.com.au

Date: 25 Jun 2006 18:18:05
From: Craig Andrews
Subject: Re: Machine Design Question- proposal

"Coffee for Connoisseurs" <alanfrew@coffeeco.com.au > wrote in message
news:8HDng.16003$ap3.11786@news-server.bigpond.net.au...
> >Do you mean that new Silvias are coming with an adjustable OPV? Will
> >this be retrofittable to the older models if so?
>
> Yes and yes.
>
>
> --
> Alan
>
> alanfrew@coffeeco.com.au
> www.coffeeco.com.au
>

Anyone have pics of that?? {;-)
Craig.

Date: 25 Jun 2006 22:34:26
From: Coffee for Connoisseurs
Subject: Re: Machine Design Question- proposal

>Anyone have pics of that?? {;-)
>Craig.

Yes. <VBG >

--
Alan

alanfrew@coffeeco.com.au
www.coffeeco.com.au

Date: 25 Jun 2006 19:33:54
From: Craig Andrews
Subject: Re: Machine Design Question- proposal

"Coffee for Connoisseurs" <alanfrew@coffeeco.com.au > wrote in message
news:SbEng.16015$ap3.9634@news-server.bigpond.net.au...
> >Anyone have pics of that?? {;-)
>>Craig.
>
> Yes. <VBG>
>
>
> --
> Alan
>
> alanfrew@coffeeco.com.au
> www.coffeeco.com.au
>

May we see them please Alan? {;-)
Craig.

Date: 26 Jun 2006 00:54:17
From:
Subject: Re: Machine Design Question- proposal

Oh all right, try www.coffeeco.com.au/ranciliovalve.jpg . Needs 2 19mm
spanners, one for the valve, one for the locknut.

--
Alan

alanfrew@coffeeco.com.au
www.coffeeco.com.au

Date: 25 Jun 2006 23:22:32
From: Craig Andrews
Subject: Re: Machine Design Question- proposal

<alanfrew@coffeeco.com.au > wrote in message
news:ZeGng.16082$ap3.6752@news-server.bigpond.net.au...
> Oh all right, try www.coffeeco.com.au/ranciliovalve.jpg . Needs 2 19mm
> spanners, one for the valve, one for the locknut.
>
>
> --
> Alan
>
> alanfrew@coffeeco.com.au
> www.coffeeco.com.au
>
>
>
>

Thank you Alan! I would assume (hopefully!) that the internal diameter
of the OPV is the same as the older models & it would retro-fit? That'd
be nice, rather than fiddling with sanding down an additional washer to
get the pressure to 9 - 9.5 bars.

If it wouldn't/doesn't fit, I'll be doing the pressure mod anyway., but
this would be great to have that adjustability at your whim! {:-D

Cheers!
Regards,
Craig.

Date: 23 Jun 2006 10:20:42
From: Omniryx@gmail.com
Subject: Re: Machine Design Question- proposal

Who even bothers to watch the US team? The US team is to real soccer
as Sanka is to real coffee. Put your money on Argentina.

Will
"Whose capacity to support Man United is nearly boundless."

I- >Ian wrote:
> > Randy "knowledge is good. It's a shame it isn't universal." G.
> > http://www.EspressoMyEspresso.com
> >GO USA! Gooooooaaaaaaaaaaaaaaaallllllllllllllllllllllllllllllllll!!!
> >
> >
>
> OT : The USA played like they already had 6 points in hand. Fairly
> obvious after 15 minutes that they were out of WC '06