Adjusting the OPV valve

C-man

Should it be done under load or what?

Lacehim

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?

UNM

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.

C-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?

Koffee_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

C-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.

derrilex

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.

C-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.

derrilex

Make the grind super fine and choke the machine and see what the reading is

C-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.

derrilex

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:

C-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

derrilex

Oh god, you've been watching those youtube vids haven't you  :D :D

C-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...

C-man

Just completed the pump speed controller It is the little white knob on the side top

derrilex

TIme to graduate to videos C-Man  :thumb:

Koffee_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

C-man

If you don't have the coin and you want to make good coffee you have to do something......

derrilex

Yep, go to Lacehims  :stir :stir :stir :rofl: :rofl: :rofl:

C-man

on 1350802240:

TIme to graduate to videos C-Man  :thumb:

here you go---