# How to adjust this type of OPV?



## greymda (Oct 6, 2016)

anyone has any experience with this type?


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## El carajillo (Mar 16, 2013)

Hold the long brass section with a spanner / grips, remove the plastic pipe and unscrew the nut. Inside I think you will find an adjuster, possibly a plain disc with a heagon hole for an allen key, this applies pressure to a spring+ seal which adjusts the pressure. (similar to Gaggia Classic)


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## greymda (Oct 6, 2016)

thank you! will try to adjust this weekend. hopefully without breaking anything)


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## El carajillo (Mar 16, 2013)

When you remove the nut, check the depth to the adjuster disc, this will give you a guide for repositioning if you remove it to clean and put you back in the ball park.


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## greymda (Oct 6, 2016)

i have a pressure gauge portafilter. it shows currently 12bar with the blind filter. i want to lower it to ~9.5


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## greymda (Oct 6, 2016)

okay, so tried this weekend, and NO SUCCESS









when hex nut removed, i see a pin in the middle and on its side there 2 in-depths what i thought i could somewhat rotate. but nothing.. i can't have a good leverage the pin being in the middle...


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## eddie57 (Mar 21, 2017)

greymda said:


> anyone has any experience with this type?


hi looks a little like my musica opv









I just loosened that nut on mine worth a try


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## greymda (Oct 6, 2016)

i did removed the nut, but inside i have this (ignore the scale, see the pin in the middle):


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## eddie57 (Mar 21, 2017)

I loosened mine a couple of turns to lower mine, the nut I mean.. I didn't remove the nut


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## Norvin (Sep 10, 2014)

Does it have a rotary or vibe pump? If has a rotary, the adjustment is done at the pump.


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## greymda (Oct 6, 2016)

no, it's a vibe pump


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## Norvin (Sep 10, 2014)

greymda said:


> no, it's a vibe pump


In which case that is likely to be the OPV. Something strange going on there.

Normally, the excess water escapes through a hole (with hexagon sides to allow adjustment) to be emptied into the water tank. It looks as if there is something broken off in the hole. Unless it is a design that I haven't come across before, best wait for someone else to identify it before taking drastic action.

If it is something broken off, you can try drilling it out or drilling and tapping a thread so that you can screw something in to pull it out; both options not possible if it is a bit of broken off allen key as it will be too hard. Otherwise you can remove the adjuster by using a simple extractor that can be made on a lathe. Then you can knock out the obstruction. I posted a thread detailing a restoration of a Gaggia OWC where I showed details of the extractor that I made to get around a similar problem.


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## El carajillo (Mar 16, 2013)

greymda said:


> i did removed the nut, but inside i have this (ignore the scale, see the pin in the middle):


Is there a sealing ring on the nut you have removed ( or "O" ring) . It may be the nut acts as an adjuster and varies the pressure on the scaled up components. As eddie57 said just moving the nut adjusted his. Possibly the valve / pin is seized in place and requires descaling and greasing ??


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## greymda (Oct 6, 2016)

i have google my OPV and came around this:


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## El carajillo (Mar 16, 2013)

The slotted disc is the adjuster, you will need an old screwdriver to cut a slot in or use a small scrap piece of metal, cut a slot in it then hold it with pliers to unscrew the disc. Fully dismantle clean , lubricate and reassemble . You may have to remove the end nut several times to get the adjustment correct.


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## greymda (Oct 6, 2016)

@El carajillo hm, it seems you're right. i need to figure a way out to make such an "instrument", thanks for the idea!


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## El carajillo (Mar 16, 2013)

You could use an old coin or a washer and cut with a junior hacksaw. You may be able to insert 2 nails / thin bolts into the slots then place a screwdriver across between them as a lever ?


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## espressotechno (Apr 11, 2011)

You may find on dismantling, that the rubber pad seal is well worn & leaky. Descaling may not cure any leaks, etc. A new OPV shouldn't be expensive....

Incidentally, an OPV is a safety valve, factory set to open at around 12 bar. ie when the water pressure in the coffee circuit is far greater than the normal 9-10 bar.


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## greymda (Oct 6, 2016)

well, we don't have here any espresso parts stores... should be fun


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