# OPV Qwestion again sorry!.



## thirteeneast (May 18, 2011)

Out of my OPV return pipe when backflusing I get 100ml of water in 30 seconds.

Is that pretty much perfect?.


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## thirteeneast (May 18, 2011)

Wakey wakey its Coffee time ???...


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## AndyL (Apr 10, 2011)

the current thinking to my knowledge is 125-130ml in 30 secs. personally I'd use a gauge and if you can be a little patient you can put your name on the list and borrow mine here.

http://coffeeforums.co.uk/showthread.php?p=18565

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## MikeHag (Mar 13, 2011)

Close enough, probably. It's not an accurate method anyway.


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## AndyL (Apr 10, 2011)

MikeHag said:


> Close enough, probably. It's not an accurate method anyway.


How did you get on with the gauge Mike?

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## thirteeneast (May 18, 2011)

Thanks for the replies.


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## thirteeneast (May 18, 2011)

To answer a question for me.

For arguments sake what would see higher volume of water at return pipe higher or lower bar?.

I am thinking lower bar = more water in return pipe is this correct?.


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## AndyL (Apr 10, 2011)

that's correct.

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## thirteeneast (May 18, 2011)

Thanks again.


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## MikeHag (Mar 13, 2011)

I couldn't use it, Andy. I thought the whole portafilter was doing the rounds but as it was just the gauge attachment, which I can't attach, I just passed it on to Michael. No worries. I'm struggling to find time to enjoy fiddling with the classic at the moment anyway. But thanks very much for sending it around









Regarding the OPs last question, I'm a little confused myself. I thought that lower pressure would mean less water being pumped through, and hence less thru the return pipe. But then again, I'm easily confused!


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## AndyL (Apr 10, 2011)

The lower the pressure the more water that's diverted back into the tank because pressure is reached quickly.

I forgot you couldn't remove your spouts.









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## MikeHag (Mar 13, 2011)

Aah - so it's the pressure threshold that's being adjusted then... makes sense.


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## AndyL (Apr 10, 2011)

That's correct Mike.

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## pendragoncs (Feb 14, 2011)

AndyL said:


> I forgot you couldn't remove your spouts.


Thought I might have had the same problem as I've tried a few times to get mine off. However they came of fairly easily when I put the porterfilter in my workbench.


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## AndyL (Apr 10, 2011)

pendragoncs said:


> Thought I might have had the same problem as I've tried a few times to get mine off. However they came of fairly easily when I put the porterfilter in my workbench.


I have to say I always thought they came off. I can't see how you can clean them properly otherwise. the first time I removed mine it was really stuck on there. It was coked up with coffee solids and oily gunk.

Mike does it look like the spout comes off or is your portafilter all in one piece?

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## MikeHag (Mar 13, 2011)

All one piece mate. Dunno why it's different from others... maybe an older model. All good.


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## funinacup (Aug 30, 2010)

Mike, you can borrow my portafilter if you like. Perfectly happy posting it to you?


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## MikeHag (Mar 13, 2011)

Thanks Michael







Very kind of you to offer. But I'm ok... like I say, not finding much time for messing about with coffee stuff at home right now due to working in the cafe, on business plans etc, and trying to find a home! Once things settle down I might take you up on the offer though. Cheers!


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## thirteeneast (May 18, 2011)

The spouts are on with non spanner adjustable thread lock. Which means there very very tight.

Post us a pic.

Regarding the OPV without pressure gauge is it not better to just put steam switch on the brew switch on and all water will be diverted to the OPV return and none to the group.

The pump in the classic delivers 260ml in 30 sec spec from ukla

The rough required measurement from the OPV Return is 130ml in 25 seconds

Can some of you guys with 10bar measured at group post some of your OPV return measurements please?.

It would make some handy reference figures.


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## MikeHag (Mar 13, 2011)

thirteeneast said:


> The spouts are on with non spanner adjustable thread lock. Which means there very very tight.
> 
> Post us a pic.


Not necessary. Like I've already said, mine is different from yours.


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## MikeHag (Mar 13, 2011)

thirteeneast said:


> The spouts are on with non spanner adjustable thread lock. Which means there very very tight.
> 
> Post us a pic.


Not necessary. Like I've already said, mine is different from yours. There's clearly more than one type of PF.


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## AndyL (Apr 10, 2011)

the problem I have with this method is that there are so many variables involved. you need to take into account the pump type and it's specified delivery rate. You have to assume that your pump is working at peak performance and that all your seals are all up to scratch. if your comparing one machine against another you have to ensure apart from the condition that everyone testing is using an identical testing methodology. Even if I told you my machine kicks out 125 ml in 25 seconds that won't guarantee the same result for you.

Build or borrow a gauge and remove the if buts and maybes out of the equation... you know it makes sense.









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## thirteeneast (May 18, 2011)

I agree,

But unless using a quality liquid filled gauge there's a big error for margin there too.


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