SJM Senior Member Joined: 17 Nov 2004 Posts: 1,508 Location: CA Expertise: I love coffee
Posted Fri Jul 6, 2007, 2:16pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
Okay now, it took me trips to five different hardware/plumbing supply places today (two of them repeats of the places I went to yesterday looking for the gauge) to find the parts to attach the gauge to the portafilter. Hurrah.
The one in the picture is the old dry gauge. Do I have to wait for the good one to come or can I experiment with this one?
And, tell me just one more time what it is that I DO with the needle gauge?
Posted Fri Jul 6, 2007, 2:28pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
That's great Susan!, however like I've mentioned before (please look above) & Tex alluded to., the gauge will be unreadable. You'll need a Snubber Valve (pressure limiting/dampening valve) pictured below to dampen the wide oscillations of the gauges needle valve that'll make the gauge unreadable without it..
However, to save more unneeded frustration & expense., try your setup without it. Like I said before & cut, copied & pasted an italicized quote of mine above, to explain the purpose of the valve., you're simulating a shot by adjusting the bleed needle valve for approx 1ml/sec (1oz shot) & this is your real time or dynamic shot.
With the valve closed off & no water flow, that's a stagnation or "blind" pressure no flow shot & that'll be 10 bars (147 psi). The real time or running shot will be approx 1 bar less, or 132 psi because of the free flow of water through the properly grind adjusted coffee pack.
Thanks, Craig. I have actually ordered a liquid filled gauge; it just hasn't arrived yet; and I think I won't need a snubber with IT, right?
And, finally, finally, finally, I think I understand, but let me try to put it in my own words so I know I know what I"m doing. I'm going to put the portafilter with the pressure gauge on the machine with the needle valve open, turn on the brew switch, and then adjust the needle valve until the volume coming through the tubing is the same as what I want for a shot: 2 oz in 25-30 seconds.
Once it is set there, I should be able to read the pressure gauge to find out what the dynamic pressure is. Yes?
I don't know why I was having such a hard time grasping the concept. I hope I've got it now. I really haven't been ignoring your information, I just wasn't processing it particularly well.
SJM Senior Member Joined: 17 Nov 2004 Posts: 1,508 Location: CA Expertise: I love coffee
Posted Thu Jul 12, 2007, 2:36pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
bump.
Still having a hard time here. The new liquid filled pressure gauge is here. I have attached it to the portafilter with a needle valve at the other end.
I have adjusted the flow through the needle valve so when I turn on the brew switch, the flow is about 2 ml in 25 seconds.
The pressure gauge doesn't even register....nada....
What am I doing wrong?
If I close the needle valve completely, the gauge reads up to 150 PSI, all of which means to me that I have mis-understood what I am adjusting with the needle valve and or something.
Taking the dogs to the park to air out my brain. Susan
Posted Thu Jul 12, 2007, 3:04pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
Hi Susan, if I had of looked more closely at your pic earlier, I would of seen that you have an inline 2 port T valve configuration. That's wrong as in your setup., you'd need a 3-way/port T valve (90° tee-off). What you have there, there's no way the water can bleed off through the right angled port to simulate the shot.
Look way back at the beginning of this thread & in my response & the 1st post to you @ the link I have there, you'll indeed see the 3 way/ported T valve that I used.
It dosen't matter though as you can just keep this valve completely closed off. Any water will then come back out of the OPV return line to the water tank. You can just adjust your OPV to a static (stagnation or "dead") pressure of 10 bars (147 psi), rounded off to 150 psi. Your dynamic or "real time" shot brew pressure will then be approx 1 bar lower @ 9 bar (132 psi).
This is what is applicable for my Silvia, & YMMV somwhat. {;-)
SJM Senior Member Joined: 17 Nov 2004 Posts: 1,508 Location: CA Expertise: I love coffee
Posted Thu Jul 12, 2007, 3:37pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
CraigA Said:
Hi Susan, if I had of looked more closely at your pic earlier, I would of seen that you have an inline 2 port T valve configuration. That's wrong as in your setup., you'd need a 3-way/port T valve (90° tee-off).
Sorry, my mistake Susan! {:-O, tired, busy & back & forth & I was/am doing dinner.{;-)
Maybe there's a problem in the configuration of the 3 ports, though? Mine has a needle valve at 9:00, the portafilter at 12:00 and the gauge at 3:00. Are you telling me that I need to change the orientation and put the portafilter at 12:00, the gauge at 3:00 and the needle valve at 6:00????
Baffled...
Sorry, no you're fine! These needle valves certainly aren't precision & a little fiddly, & you may just opt to close it off & adjust for stagnation/static (no flow) pressure.
O.T. I see your posts on the Gaggia OPV were answered soon enough, & my recent post/s got me nowhere., about Subject: Compatible Grouphead Gasket * Expobar E61 Grouphead * So I'll ask my question here or on another thread, or the HB forums..
Quote:I've just aquired an Expobar Office Leva. What other compatible E61 grouphead gasket will fit please? Thanks, Craig.'
Would a Rancilio Miss Silvia 8mm grouphead gasket fit & work? TIA!
As to your question, I've never even seen a E61, so that is totally unknown territory for me. You might better post it as its own topic to get better visibility, though....
As to your question, I've never even seen a E61, so that is totally unknown territory for me. You might better post it as its own topic to get better visibility, though....
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 12, 2007, 4:47pm Subject: Re: Is there a way to test the OPV valve when it's off the machine?
O.T. I see your posts on the Gaggia OPV were answered soon enough, & my recent post/s got me nowhere., about Subject: Compatible Grouphead Gasket * Expobar E61 Grouphead * So I'll ask my question here or on another thread, or the HB forums..
Quote:I've just aquired an Expobar Office Leva. What other compatible E61 grouphead gasket will fit please? Thanks, Craig.'
Would a Rancilio Miss Silvia 8mm grouphead gasket fit & work? TIA!
I would bet that any e61 group gasket would work. Look for anything with a 75/76mm outside diameter, 56mm inside diameter & 8mm thick. Faema for instance.
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
![SJM: IMG_2264.JPG](javascript:ImagePopup("/images/33048/IMG_2264.JPG", 640, 480, "SJM: IMG_2264.JPG");)
![SJM: Pressure Tester for Brew Head.JPG](javascript:ImagePopup("/images/33162/PressureTesterforBrewHead.JPG", 640, 480, "SJM: Pressure Tester for Brew Head.JPG");)
![CraigA: E61 Grouphead1.jpg](javascript:ImagePopup("/images/33166/E61Grouphead1.jpg", 800, 618, "CraigA: E61 Grouphead1.jpg");)
![CraigA: E61 Grouphead.jpg](javascript:ImagePopup("/images/33164/E61Grouphead.jpg", 162, 209, "CraigA: E61 Grouphead.jpg");)
= No New Posts since last visit 