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Adjusting the OPV valve

C-manC-man
edited January 1970 in Have your say
Should it be done under load or what?
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Comments

  • LacehimLacehim
    Or what.  Really you need a gauge to see what you are doing, otherwise your just adjusting it blind. What are you adjusting it on anyway?  New machine or the old Krupps?
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  • UNMUNM
    I adjusted the opv on my gaggia with no gauge, based on documented ulka pump flow rates. Better than before, even if not entirely accurate. Adjusting opvs depends a lot on the equipment. Ideally it should be done while pump is running and flow rate is similar to a perfect extraction. This is rarely possible though.
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  • C-manC-man
    I do have a gauge that I am fitting with the OPV valve So I should load a puck then adjust during extraction or what?
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  • Koffee_KosmoKoffee_Kosmo
    on 1350696316:
    I do have a gauge that I am fitting with the OPV valve So I should load a puck then adjust during extraction or what?
    Depends on the guage I am pretty sure that you can't load 99.9% of gauges with coffee as they are constructed with a false bottom A false bottom acts as resistance KK
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  • C-manC-man
    Well I nailed it!  first after I installed everything I ran some water through with no reading on the gauge, then I tried a pressurized basket and got around 4 bar on the gauge. Then I ground some coffee and did my normal thing and the gauge pegged out  straight away around 15 bar, so I quickly adjusted to back to 9 bar wile the shot was still running. Works a treat now with a steady 9 bar , coffee is now seamless, much better even with my El-cheapo machine. I don't know if it is the valve or the fact that I altered the pump mount, but it is very quiet now. thanks to karl over at CS for the Idea and some pointers.
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  • derrilexderrilex
    But that reading is based solely on the resistance of that particular puck. As AM said, it can't be done while using coffee. You need to put a gauge on the bottom of the PF and adjust to OPV to bypass at whatever pressure you want.
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  • C-manC-man
    well I changed the grind, tamp ect and it still bleeds off at 9 bar where I set it according to the gauge anyway.
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  • derrilexderrilex
    Make the grind super fine and choke the machine and see what the reading is
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  • C-manC-man
    I have done that, it stays at 9 bar no matter as the excess water pressure just bleeds off. If you take a 15 ltr bucket and drill big holes all around it at the 9 ltr mark no matter how fast you try to fill it the water will just run out and it will stay at 9 ltrs It is simple plumbing, shit runs downhill and payday is on Friday.
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  • derrilexderrilex
    I suspect you have just invented a new way to adjust the opv. You can call it the "American Style"  :D It aint right, but if you're happy thats all that matters. :thumb:
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  • C-manC-man
    It works great! the pump is much quieter and results in the cup are much, much  better Now I am working on a pump speed control so I can start the extraction at 9 bar then drop it down to around 4-5 bar depending on the flow rate
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  • derrilexderrilex
    Oh god, you've been watching those youtube vids haven't you  :D :D
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  • C-manC-man
    Just having some fun sense I picked up a cheap machine $15 in mint cond. $100 for mods  ( Vibiemme OPV and a 16 bar gauge)  and so far it is working unbelievably well...
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  • C-manC-man
    Just completed the pump speed controller It is the little white knob on the side top
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  • derrilexderrilex
    TIme to graduate to videos C-Man  :thumb:
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  • Koffee_KosmoKoffee_Kosmo
    I am always amazed at the enginuety of the human race Anything can be archived if a little thought and effort is applied  :thumb: KK
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  • C-manC-man
    If you don't have the coin and you want to make good coffee you have to do something......
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  • derrilexderrilex
    Yep, go to Lacehims  :stir :stir :stir :rofl: :rofl: :rofl:
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  • C-manC-man
    on 1350802240:
    TIme to graduate to videos C-Man  :thumb:
    here you go---
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