# Gaggia Classic OPV



## omegabri (Jan 7, 2014)

Hi guys

Wanting to get the best from my Gaggia Classic I was wondering how important setting the OPV value is???

Does the extra pressure force the shot too fast, being that it's probably on 11 or more from the factory....and the ideal for espresso is with the machine at 9 lbs

Bri &#8230;


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## badger28 (Jan 5, 2013)

I only set my opv to 9 bar within the past week (had the machine for a year now) and noticed an immediate improvement in my espresso. Mostly in pour and mouth feel.

I haven't used a gauge though. I measured the output however will get a gauge at some point to confirm the setting.

If I wanted to attach a permanent gauge to the classic could I put it inbetween the pump and boiler? This is the easiest place that I can see to put it but would it measure the right pressure?


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## Milanski (Oct 10, 2013)

Setting the OPV at 9 bar gave me more consistency and a better shot instantly.

The 'Over Pressure Valve' does not apply the pressure of the shot being made. It's setting determines a point at which any excess pressure (and therefore water) exits out of the little tube into the drip tray. This means the MAXIMUM pressure the machine can then make coffee at is 9 bar.


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## El carajillo (Mar 16, 2013)

The OPV is exactly that over pressure valve. It releases the excess water pressure back to the tank. New machines are often set at 15 bar to allow the use of pressurised and pod baskets. For freshly ground espresso it is usual to reset the OPV to between 10 and 11 bar static (no basket and a pressure gauge attached to PF ) This then gives a working/ running pressure of about 9 bar (also allows for pressure ramp up with vibration pumps)

The only way to adjust and set accurately is with a gauge, it cannot be done by guess work and flow rates are too variable.


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## El carajillo (Mar 16, 2013)

Sorry Milanski the excess water from OPV returns to tank not drip tray. Second pipe in tank is return from OPV


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## omegabri (Jan 7, 2014)

I was gonna try just turning down the valve (being anti-clockwise), about 180 degree's(ish). I have no pressure gauge, but I'll start to look into that as my next job after I have sorted and set up my grinder this week - hopefully!......

Thanks for the info guys

Bri....


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## coffeechap (Apr 5, 2012)

Yep with El carajillo here the metal tube is the decompression pipe from the solenoid.


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## omegabri (Jan 7, 2014)

The clear tube from my OPV has water in it, so I know it's dragging un-needed pressure out (i guess !?!?







)


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## Milanski (Oct 10, 2013)

El carajillo said:


> Sorry Milanski the excess water from OPV returns to tank not drip tray. Second pipe in tank is return from OPV





coffeechap said:


> Yep with El carajillo here the metal tube is the decompression pipe from the solenoid.


Of course it is. I stand corrected. Thanks guys.


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## El carajillo (Mar 16, 2013)

Milanski you cannot start having my senior moments


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## Charliej (Feb 25, 2012)

El carajillo said:


> Milanski you cannot start having my senior moments


Or mine I've waited a long time to be entitled to them lol


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## Milanski (Oct 10, 2013)

El carajillo said:


> Milanski you cannot start having my senior moments










I know, I'm starting to think all that aluminium in my Classic is giving me Alzheimer's!?


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## omegabri (Jan 7, 2014)

I've turned my OPV anti-clockwise 180 degrees today........ I have no pressure gauge to accurately drop it to 9 lb but I figure 180 deg turn is better than nothing at the moment


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## t4tom (Jan 5, 2014)

omegabri said:


> I've turned my OPV anti-clockwise 180 degrees today........ I have no pressure gauge to accurately drop it to 9 lb but I figure 180 deg turn is better than nothing at the moment


How does it taste?

I just took receipt of my Gaggia Classic today. I am still trying to find a good grinder and have my eye on some other goodies.


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## lookseehear (Jul 16, 2010)

I found that before changing my OPV back when I had a classic I would have to grind a lot finer to get the shot in 'normal' parameters. After the adjustment I had a bigger usable range on my grinder and dialling in was easier, as well as consistently better tasting shots. There is a guide on here somewhere to making a guage pretty cheaply (under £10 I think). I lent my gauge out and never got it back in the end!


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## omegabri (Jan 7, 2014)

Tastes better I think - considering I'm using pre-ground - BUT !!!!! my 'Noir' edition MC 2 auto grinder is due tomorrow from Happy Donkey !!!!!! yey !!!!















, so I'll be trying it all out on my order from Rave (which came today !







)

Sorry to hear about the pressure gauge not returning !?!?! How crappy is that of someone !?!?!?!?

Bri...


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## lookseehear (Jul 16, 2010)

omegabri said:


> Tastes better I think - considering I'm using pre-ground - BUT !!!!! my 'Noir' edition MC 2 auto grinder is due tomorrow from Happy Donkey !!!!!! yey !!!!
> 
> 
> 
> ...


If you've been using happy donkey pre ground you'll Be in for a real treat with Rave beans and your mc2.

To be fair with the gauge I didn't really pursue it as I don't need it any more but its a shame that it isn't still knocking around to be borrowed.


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## omegabri (Jan 7, 2014)

Used grinder today with the free beans that came with it. Gaggia made gorgeous shots...all seems to be running fine with the OPV turned. Coffee tastes stunning. I'll get the beans from RAVE through the grinder when the free ones run out.


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## omegabri (Jan 7, 2014)

I've just tweaked my OPV another 70 degree's. That's 250 degrees now from factory setting, and I have to say.......it's hit the nail on the head now !! I don't know why, or how, but it's pulling an amazing shot now. The taste and feel of the coffee is sublime ! Happy days !!!!









p.s. I've no pressure gauge so I have no idea before anyone asks what the current pressure is - but it works !! OMG it works !!!! lol


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## oracleoftruth (Jan 15, 2014)

Guys, there is no need for all this guessWork. I made a portafilter gauge for about 8quid in total.

The brass bush to connect the portafilter, a 5quid gauge and some thread tape. It works perfectly well.

if anyone is near sheffield they can borrow it or just get down to a plumbing shop. The guage was harder to get but ebay has them or if you are in sheffield you can get one from the importers.


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