# Adjusting the OPV on pre 2015 classic .



## Gilly (Jul 29, 2019)

Hello everyone. Just want to know why it's generally considered better to adjust the classic from 15BAR to 9 bar pressure.

What are the advantages in lowering the factory setting?

I have a portafilter with gauge attached and was wondering how to do this?

Thanks Jill

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## MrShades (Jul 29, 2009)

Hi Jill

There's plenty of posts on here concerning the lowering of the pressure on the OPV to 9 bar - but in a nutshell, you take the pipe and the top off the OPV itself and then - using an allen key - turn a screw down inside the OPV. Typically you turn it only around 270degrees, but adjust and reassemble it and then test the pressure with your portafilter/gauge.... you're looking for 10bar static pressure (which equates to 9bar dynamic pressure).

Start reading here:

https://www.coffeeforums.co.uk/articles/articles/Adjusting-the-OPV-(over-Pressure-Valve)-Gaggia-Classic/?do=embed

Usually the manufacturers are setting the machines to 15bar, because that's what the coffee-pod manufacturers dictate. So if they want to be able to state that amchine X works with coffee pods from manufacturer Y, then they have to ensure that the machine can hit 15bar. Which is pretty crazy, as almost every commercial (and prosumer) espresso machine is set to 9 bar, and often less.

Hope this helps,


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## Caffeine fan (May 14, 2019)

I followed the article referenced by MrShades on Saturday using the tools indicated. It was actually very straightforward and took around 45 mins.


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