Hi to all...
I am on week 2 with the S1 and am very content but now it's time to fiddle. I just received the S1 PF with gauge from Chris Coffee. From what I've read here I need to fill it with water first (clean water), engage, press brew button and then I can see the current adjustment. I saw on the S1 site how to adjust so should be ok there. What are you all setting the brew pressure at?
Line pressure. I also received a pressure regulator for the feed line. I have my S1 plumbed to a 'T' after an RO system. No idea what the current line pressure is but I'm sure it fluctuates. So now I'll have a gauge and regulator to play with. How much does the line pressure effect the brew pressure? Does it affect brew pressure at all? I also (like many here) have the dripping expansion valve so I'll be curious to see if that resolves with less inlet pressure.
Any comments/experience with these variables is appreciated.
Jay
Brew Pressure and Line Pressure?
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javajay
So here are my results-What the machine has been at for the last 10 days....
Line pressure reads 60psi when there isn't a draw from either the S1 or my RO tap. With a draw it reads 40psi. This is higher than I expected and I believe it's higher than it should be. Please chime in...
Then I checked brew pressure. This really suprised me. 12.5 bar! I'm wondering if my machine wasn't calibrated before shipping. I thought CC went for 8-9 bar. Hopefully I ran the test correctly. Originally I put in a single basket thinking it would seal better to the group gasket but instead water escaped rapidly between the basket and PF. So then I just locked in the PF with no basket and the seal was tight. No leakage. 12.5 bar. I did try to fill the copper line to the gauge with water but it didn't seem possible to prime that line. The water I added to the PF just sat in the PF without entering the copper line to the gauge. Not sure if this may be giving me a false reading. How long is too long to have the brew gauge pinned at highest pressure for testing (12.5 in my case)?
If my machine is in fact set to 12.5 bar then that may explain some of the channeling issues I've been having. I've been very attentive to dose, grind, and tamp!
Thanks for any help...
Jay
[edit] Update: I have not adjusted anything and now I am consistently getting 8.2 bar on the group gauge. Hmmmm... I did notice before that when the group gauge went up to 12.5 the expansion valve started to drip. I'm a bit confused.
Line pressure reads 60psi when there isn't a draw from either the S1 or my RO tap. With a draw it reads 40psi. This is higher than I expected and I believe it's higher than it should be. Please chime in...
Then I checked brew pressure. This really suprised me. 12.5 bar! I'm wondering if my machine wasn't calibrated before shipping. I thought CC went for 8-9 bar. Hopefully I ran the test correctly. Originally I put in a single basket thinking it would seal better to the group gasket but instead water escaped rapidly between the basket and PF. So then I just locked in the PF with no basket and the seal was tight. No leakage. 12.5 bar. I did try to fill the copper line to the gauge with water but it didn't seem possible to prime that line. The water I added to the PF just sat in the PF without entering the copper line to the gauge. Not sure if this may be giving me a false reading. How long is too long to have the brew gauge pinned at highest pressure for testing (12.5 in my case)?
If my machine is in fact set to 12.5 bar then that may explain some of the channeling issues I've been having. I've been very attentive to dose, grind, and tamp!
Thanks for any help...
Jay
[edit] Update: I have not adjusted anything and now I am consistently getting 8.2 bar on the group gauge. Hmmmm... I did notice before that when the group gauge went up to 12.5 the expansion valve started to drip. I'm a bit confused.
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Barry
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Tim
From what I understand, the rotary pump merely increases incoming water pressure a set amount so changing the input pressure will affect the output pressure. I'm not sure what pressure Chris uses when they set the machines up prior to shipping, but I'm sure that it isn't as high as 60 psi. Try reducing your inlet water pressure to around 30 psi without flow and then adjust your brew pressure. Good luck!
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chas
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If the expansion valve is properly adjusted it is supposed to open at 12.5bar. So the fact that you were reading 12.5bar on the gauge and the valve was dripping makes you wonder if it really was that high! Glad it resolved itself in any case.javajay wrote: [edit] Update: I have not adjusted anything and now I am consistently getting 8.2 bar on the group gauge. Hmmmm... I did notice before that when the group gauge went up to 12.5 the expansion valve started to drip. I'm a bit confused.
Chas
LM GS/3 & LaSpaziale Dream v 1.25 (US 120V)
Mazzer Kony E, Customized Rocky
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LM GS/3 & LaSpaziale Dream v 1.25 (US 120V)
Mazzer Kony E, Customized Rocky
Hottop P/B
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bobroseman
Here is my understanding. Take the line pressure say 4 bar add it to the pump max output of 16 bar but adjust your bypass valve to 8.5 bar and you get 8.5 bar to the portafilter. If the line pressure drops to 2 bar you still get 8.5 and not 6.5 bar into the portafilter. This agrees with my observaions.Tim wrote:From what I understand, the rotary pump merely increases incoming water pressure a set amount so changing the input pressure will affect the output pressure. I'm not sure what pressure Chris uses when they set the machines up prior to shipping, but I'm sure that it isn't as high as 60 psi. Try reducing your inlet water pressure to around 30 psi without flow and then adjust your brew pressure. Good luck!
Bob
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alsterling
Info. on initial setting of brew pressure at pump...
Because I had been fighting for a better extraction from my Malabar Gold, and because of the wet-puck syndrome, and after adjusting everything from the grind, tamp, temp........and even opening and closing the living room blinds!!!..........I finally built a test gage and checked the brew pressure.
My S1 shipped out last month and measured Monday at 135psi, which is about 9.3 bar. I called Roger at Chriscoffee, and he said that unless otherwise requested, they set them at 9-10 bars. I called Dr. John at Josuma and, sure enough, he recommended 8 bars of brew pressure, with optimally some pre-infusion. He explains that his coffee is roasted up to but not including an oily bean. The blend is very dry, and most machines build pressure too quickly and too high, thus "pin holeing" the puck. Pre-infusion helps to "gel" the puck and provide an even extraction. Well, forget true pre-infusion. I did try using a 2 second pulse from the single shot button. It really didn't change my extraction much, if at all.
I hit the double button and wait about 6 seconds for the first gushing of creama, then at 17 seconds the "molten lava" changes to a more watery blonding rat's tail. The shot ends, right now, at a very consistent 28 seconds. Dr. John recommends 25 total seconds from the time the coffee starts to exit the PF.
Bottom line........ I adjusted the pump down to 120psi, or 8.2 bar. Just thought you'd like to know what happened. And by the way, cycling the PF test unit is always a good idea as it's like bleeding the air out of a brake system. I used the single shot button in the setting mode to cycle the pump. Also.....I had to remove the basket to avoid leaks at high pressure. Once removed, my testing was quit consistent and the whole process was rather easy; easier than I had imagined.
Well......anyway.....that's my story and, yes, I'm sticking to it.
Best, Al in SoCal
My S1 shipped out last month and measured Monday at 135psi, which is about 9.3 bar. I called Roger at Chriscoffee, and he said that unless otherwise requested, they set them at 9-10 bars. I called Dr. John at Josuma and, sure enough, he recommended 8 bars of brew pressure, with optimally some pre-infusion. He explains that his coffee is roasted up to but not including an oily bean. The blend is very dry, and most machines build pressure too quickly and too high, thus "pin holeing" the puck. Pre-infusion helps to "gel" the puck and provide an even extraction. Well, forget true pre-infusion. I did try using a 2 second pulse from the single shot button. It really didn't change my extraction much, if at all.
I hit the double button and wait about 6 seconds for the first gushing of creama, then at 17 seconds the "molten lava" changes to a more watery blonding rat's tail. The shot ends, right now, at a very consistent 28 seconds. Dr. John recommends 25 total seconds from the time the coffee starts to exit the PF.
Bottom line........ I adjusted the pump down to 120psi, or 8.2 bar. Just thought you'd like to know what happened. And by the way, cycling the PF test unit is always a good idea as it's like bleeding the air out of a brake system. I used the single shot button in the setting mode to cycle the pump. Also.....I had to remove the basket to avoid leaks at high pressure. Once removed, my testing was quit consistent and the whole process was rather easy; easier than I had imagined.
Well......anyway.....that's my story and, yes, I'm sticking to it.
Best, Al in SoCal