SJM Senior Member Joined: 17 Nov 2004 Posts: 1,129 Location: CA Expertise: I love coffee
Posted Wed Jul 4, 2007, 4:48pm Subject: Is there a way to test the OPV valve when it's off the machine?
...before putting it back into the machine (Gaggia) and hooking everything back up?
We're talking about the OPV from the Orange Baby Gaggia, here. It's all removed from the boiler and clean as a whistle, but I don't have a clue how snugly to screw down the adjuster to start, or if there is anything else that could be wrong with it.
Tex Senior Member Joined: 27 Apr 2006 Posts: 840 Location: Texas - That's God's country to everyone else! Expertise: Professional
Espresso: Bunn ES-1A (PID'd), Gaggia... Grinder: Rancilio MD50 Vac Pot: Way too many vintage Silex... Drip: Melitta Clarity Roaster: TurboCrazy &...
Posted Wed Jul 4, 2007, 6:22pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
SJM Said:
...before putting it back into the machine (Gaggia) and hooking everything back up?
We're talking about the OPV from the Orange Baby Gaggia, here. It's all removed from the boiler and clean as a whistle, but I don't have a clue how snugly to screw down the adjuster to start, or if there is anything else that could be wrong with it.
I suppose one could rig a test bed for the OPV, but it'd certainly be easier to test it on the boiler. Here's a link showing how a pressure gauge can be rigged for ~$25. This one lets you perform a static or dynamic brew/group pressure test & has a liquid filled gauge for better accuracy.
SJM Senior Member Joined: 17 Nov 2004 Posts: 1,129 Location: CA Expertise: I love coffee
Posted Wed Jul 4, 2007, 7:03pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
Tex Said:
I suppose one could rig a test bed for the OPV, but it'd certainly be easier to test it on the boiler. Here's a link showing how a pressure gauge can be rigged for ~$25. This one lets you perform a static or dynamic brew/group pressure test & has a liquid filled gauge for better accuracy.
Okay, that takes me back to a previous unanswered question of mine. The pressure gauge I used last week was a dry gauge, and it was simply threaded onto the bottom of the portafilter (with one intervening connector).
*What is the purpose of the needle valve assembly on yours, and *Will the one I was using "damage my non-solenoid Coffee?
Yours is definitely prettier, but....do I really need it?
Oh yeah, and what is the difference between a static and a dynamic pressure test?
Hi Susan, did you happen to read past that one post on the link I posted hopefully? I explained what the needle valve does., you can adjust to bleed off some water., approx 1 ml/sec to approximate a shot in real time (dynamic).
Yours is definitely prettier, but....do I really need it?
Probably not, but if ya want it to last..
Oh yeah, and what is the difference between a static and a dynamic pressure test?
I've explained it back in my posts in that link above..., & just recently 6 hrs ago Wed July 4th here: Click Here (www.coffeegeek.com)
Quote from another post:"I can set for stagnation (blind) or dynamic pressure, simulating a shot., or pulling a real shot & measuring exact extraction brew pressure. Stagnation or static (blind) pressure for a Silvia, although not the best way to measure it., should be set for 10 - 10.5 bars & for a dynamic simulated or real shot, the pressure set to 9 - 9.5 bars., (1 bar lower to account for dynamic {running} pressure drop) depending on your particular espresso blend recommendations (temp @ grouphead & extraction pressure)."
Tex Senior Member Joined: 27 Apr 2006 Posts: 840 Location: Texas - That's God's country to everyone else! Expertise: Professional
Espresso: Bunn ES-1A (PID'd), Gaggia... Grinder: Rancilio MD50 Vac Pot: Way too many vintage Silex... Drip: Melitta Clarity Roaster: TurboCrazy &...
Posted Wed Jul 4, 2007, 11:01pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
Okay, that takes me back to a previous unanswered question of mine. The pressure gauge I used last week was a dry gauge, and it was simply threaded onto the bottom of the portafilter (with one intervening connector).
*What is the purpose of the needle valve assembly on yours, and *Will the one I was using "damage my non-solenoid Coffee?
Yours is definitely prettier, but....do I really need it?
Oh yeah, and what is the difference between a static and a dynamic pressure test?
Susan the curious....
Howdy Susan!
Static test - water is trapped in the brew group. Because there's no flow the results don't mirror what you'd get pulling a shot.
Dynamic test - The needle valve simulates the flow of water through the filter. The results are identical to what you'll get when you pull a shot.
I tried a dry gauge originally but the flutter was such that accurate testing was impossible. If yours doesn't have the flutter it'll be OK, no damage will be caused to your machine.
Oh dear, sorry Craig, you are right that I didn't read your response thoroughly enough to see that in fact my question HAD been answered.
Thanks to you and Thanks to Tex for telling me AGAIN.
I'm gonna go to the hardware store today and get the parts for a better pressure checker. Since my new PID kit will be coming soon for the Coffee and the Orange Baby will be going back together again soon, I will want to be able to check them both out.
Tex Senior Member Joined: 27 Apr 2006 Posts: 840 Location: Texas - That's God's country to everyone else! Expertise: Professional
Espresso: Bunn ES-1A (PID'd), Gaggia... Grinder: Rancilio MD50 Vac Pot: Way too many vintage Silex... Drip: Melitta Clarity Roaster: TurboCrazy &...
Posted Thu Jul 5, 2007, 7:14pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
I'm gonna go to the hardware store today and get the parts for a better pressure checker. Since my new PID kit will be coming soon for the Coffee and the Orange Baby will be going back together again soon, I will want to be able to check them both out.
Susan
So, what'd you end up with? It's show & tell time.
Do you really want to hear about how completely annoying it was to go to the salvage yard and two large hardware sorts of stores and find NO liquid filled pressure gauges. It wasn't so bad that they didn't have them, but the level of condescension when the sales(yup)men looked over their glasses at me and said "what's it for" as if .....Okay, okay, okay, I'm not going to go there. They were supremely unhelpful and annoying, and I can't help but wondering if I would have gotten just the tiniest bit more respect for my query had I not been a (ha ha ha) girl.
Rant over.
I've ordered the liquid filled gauge from the gaugestore and will have to wait for several days for it to arrive. Meanwhile I'll head back out to the local stores to find the brass fittings so they are here when my gauge comes. AND, I have to scrape all that nasty RTV off the boiler so I can put more back on and closer her up again....
AND it's too darn hot here
Okay, so the rant wasn't over, but now it is....Are you sorry you asked
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