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Testing Silvias pressure without a gauge

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  • BanjoPaterson
    replied
    Hating to add to this thread. I've a Rancilio Silvia v6 and adjusted the OPV to show 10 bar (+/- 0.5) on a portafilter static gauge and double checked with a flow rate of 130ml per 30 seconds +/-5ml. Happy that this is as close as I can get to "9 bars"; but at what?

    Should this be at the pump or the group? Listening to James Hoffman for the 1500 pound machines, he talks about 9 bars at the pump. Also, the OPV spring kit for my Gaggia from Shades of Coffee would be a definite 9 bar at the pump (OPV connected directly to pump) and much less at the group. But this seems odd, because the loss between the pump and the group is not constant between machines - and 9 bar on a lever machine is, I expect, at the group. My question is: is it 9 bar at the pump or the group?

    I check earlier in this thread where someone mentioned that a static gauge of 10 at the group is the "maximum". I presume this is when checking the Ulka E models for the E5 (http://ulka-ceme.co.uk/Ulka_E_Models.html) you look at the red line, in which case it give 8 bars at the group and means 9 bars at the pump.

    It all seems akin to using chicken bones and entrails to adjust the brew pressure to the correct setting. Any advice gratefully received.

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  • darrend
    replied
    Thanks folks

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  • Dimal
    replied
    Ditto...

    Mal.

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  • level3ninja
    replied
    If you're asking whether estimating or measuring with a gauge is more accurate I'd trust the gauge.

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  • darrend
    replied
    Ha ha, not much has changes in the coffee world.

    I've adjusted my OPV to about 9.5 on the gauge, which would be less than 9 bar on the volume/time method. Once I get the grind dialled I'll see how she goes.

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  • robusto
    replied
    Good heavens. I started this thread 14 years ago. Has it been that long? Where did the years ago....

    Darrend, There will always be variation between different gauges unless they have been calibrated and verified. If the discrepancy is just 1 bar I wouldn't lose sleep over it.

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  • darrend
    replied
    Just reviving an old thread. I recently completely disassembled, cleaned and re-assembled my Silvia V3. At the time, I did not have a portafilter pressure gauge, so used the pump output volume/time method to estimate the 9 bar pressure and correct OPV adjustment. Now that I've received my Joe Frex pressure gauge, it's showing about 10 bar at the portafilter. The question is, which method is more accurate?

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  • Bames
    replied
    Re: Testing Silvias pressure without a gauge

    Hey all
    Sorry to resurrect an old thread, but just looking at the flow rates of the pump has got my kinda worried. I have an Oscar with an EP5 pump (borrowed from my Sunbeam as the Oscars pump died). According to Ulkas data, with 0 pressure this pump should pump ~630ml of water per minute, and this is what the pump was doing when it was in my Sunbeam.
    However - when in the Oscar, it will pump out more like ~900ml per minute... which more than the maximum the pump is rated at, and more than is even on their graph!
    Is this a problem? Is the Oscar drawing to much power and overloading the pump? I have a slight suspicion that the Oscar might be an O/S model with a retro-fitted Aus plug, cause the plug looks retro-fitted! The plate on the bottom says its the 240V version though...

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  • takai
    replied
    Re: Testing Silvias pressure without a gauge

    Originally posted by 2D292B25212E242B252C33400 link=1143622054/67#67 date=1290285354
    its a bit late - all the info seems to be up here throughout this long thread - but i collected my research and experimentation on this topic a few months back in my blog (http://coffee.hastie.id.au/pressure-...ion-for-silvia) which might be helpful.

    6 months after i modified the pressure (reduced it since silvia runs a little high) i heard a pretty ugly metal noise. for a fews days the coffee tasted weak. i tested the pressure and found it low and on opening it up the lock nut had come loose - hence the noise! so do her up nice and tight!! fixed her up and shes pouring well again.
    Just to resurrect this slightly. Is the flow rate for the Ulka E5 correct for the current generation (S3) of the Silvias?

    I read somewhere, but cant find it now, that Rancilio changed the pumps for the S3 model.

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  • mikeandkels
    replied
    Re: Testing Silvias pressure without a gauge

    its a bit late - all the info seems to be up here throughout this long thread - but i collected my research and experimentation on this topic a few months back in my blog (http://coffee.hastie.id.au/pressure-...ion-for-silvia) which might be helpful.

    6 months after i modified the pressure (reduced it since silvia runs a little high) i heard a pretty ugly metal noise. for a fews days the coffee tasted weak. i tested the pressure and found it low and on opening it up the lock nut had come loose - hence the noise! so do her up nice and tight!! fixed her up and shes pouring well again.

    Leave a comment:


  • Dimal
    replied
    Re: Testing Silvias pressure without a gauge

    Gday "satd"....

    As mentioned elsewhere, this method is a very rough way to get your machine into the ballpark of 9.0BAR Brew Pressure. Its a much better idea to take your machine to one of the Site Sponsors, if possible, and have your machine tested and setup properly. Alternatively, you could contact Greg Pullman and hire his Group Handle Gauge Kit and use this to arrive at a known, exact Brew Pressure Setting.

    Much better way to do things in my view.... 8-)

    Mal.

    Leave a comment:


  • satd
    replied
    Re: Testing Silvias pressure without a gauge

    Hi,

    I tried the other night to do this and wasnt very successful - using the flowrate method I found my current pressure to be ~ 6 bar so I tried increasing the pressure by tightening the OPV valve.... but after testing it out, the machine just didnt have any water coming out at all through the return hose and the pump sounded rather loud :-X so I lowered the pressure again and again until there was water coming back through the hose..... and now its back to ~6 bar Hmmmm.....:S Any thoughts? I thought I might have adjusted it a bit much but really I only made a quarter turn at most....

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  • dumiya
    replied
    Re: Testing Silvias pressure without a gauge

    Hi
    This is so embarrassing.  For several years I have wanted to adjust the Silvia but thought it might be too hard.

    Well It took all of 60 seconds to do once I had the top off and had purchased a 20 mm open ended spanner (Shifting spanner is too wide and bulky).  I only had to remove the top cover. With shifting spanner I would have had to remove the sides

    1. Measure the pressure by what ever means
    2. Remove power cord from the GPO.  Take top off
    3. Locate lock nut  loosen with a 20mm spanner
    4. unscrew the brass pressure end piece about 1 turn
    5. Replace cover (dont screw) to stop the temptation to adjust while powered up.
    6. turn on and remeasure by what ever means.
    7. Continue adjusting testing and adjusting until satisfied
    8. Tighten lock nut with out moving the adjusting piece.
    9. Test again

    (A gauge make it process very simple. One can be hired if necessary. I used a PF with gauge ($108± @ Coffee Parts)  I found the e 61 version worked well on Silvia and I can use it on the Giotto as well) Most of the wiring is insulated and safe to look at but if powered up there is a strong possibility of an accident.  So pull plug before venturing below the cover.

    D

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  • dumiya
    replied
    Re: Testing Silvias pressure without a gauge

    Hi
    I did not notice this thread.
    I am in the process of adjusting my 06 Silvia.
    It is reading about 9.5 to 10 bar which is quite good.  The gauge (Coffee Parts) is not a liquid one so it is not steady.  I want to set it averaging around 9bar  ( I think the gauge is reading a bit 5-10% higher that Greg Ps liquid one.  When I rented Gregs I was not confident to do the adjustments, now I am!

    Because the nuts are quite close i think a 20mm open ended spanner will be thin enough for the lock nut. It will not foul on the OPV body.  I will check out the size tomorrow. The cresent (shifting spanner) should be ok if the screw out part need loosening from the loosen lock nut. But when finished and to tighten the lock nut the two spanner will be needed. One to hold the position the other to tighten the lock nut (as in a bicycle hub - whats that you say)
    This thread has been very helpful and answers my posts questions

    Dumiya

    Leave a comment:


  • mutts
    replied
    Re: Testing Silvias pressure without a gauge

    Aloha. Been some time i know, but was wondering what finally worked to loosen the Silvia OPV nut and valve and also how much adjustment was settled upon... trying to do the same. thanks.

    Leave a comment:

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