Ive deliberately posted this as a new discussion outside the main evo discussion, will be easier to dump and delete if it goes south!!

It is not a moan or fault report in any way so please read on and please comment.

I was thinking about the non return valve swap out recently done by @BillyG and as he said there was nothing obviously wrong with the valve i wondered if it could simply have been a faulty spring inside the valve.

The video at the bottom ive hopefully recreated the issue using “non standard” settings.

Would be interested if your thoughts @BilliumB

It may also add information for @selmerfudd from his earlier question

"" selmerfudd Let us say the auto flush setting is set to 4.9 bar for a double shot and the pre-infusion setting is set to 5.5 bar- in this case because the pump cycles its way to the full five bars of pre-infusion instead of ramping slowly - and does so in pulses of pump activity causing a bouncing pressure as the grinds absorb the pre-infusion water – the auto flush will engage and empty the group of its water during pre-infusion –this could have been thought out and thus preventing the auto flush to engage so early""

@“DavecUK”

The video……

So, i was initially looking what pressure qas required to keep the pump running against the pressure build up from the restriction that is the “safety sleeve” (seems to be around 3.5 bars but it’s not important!)

What ive stumbled across is how to recreate the pulsing seen by @“BillyG” along with a theory that may mean he had a faulty spring in the non return (one way) valve.

If you look you will see mine pulsing above 4 bars which im now assuming is the pressure required for my particular valve to overcome the spring pressure of the valve. That lets water seep past, pressure drops and the pump tops it up.

In this instance it is not a fault but a consequence of using non-standard parameters which im going to suggest is pre infusion over 3 bars!!

Billys original post https://coffeetime.freeflarum.com/d/10-acs-vesuvius-evo-leva/4753

@selmerfudd

If you think the above more fully explains what you were originally asking and warrants an apology feel free to jump in!! Still comes back to the same suggestion “use standard ish parameters” but may have been part of the pulsing you described but further complicated with your overlapping parameters from pre infusion and dump….. 😧