What is "pump pulse" preinfusion?

[tweeek]

I've just read through the Pro's Perspective on the GS3 and it crystallised a question a question I've been considering for some time.

Can anyone explain pump pulse preinfusion to me, my understanding is that it is a preinfusion based on reduced volume as opposed to reduced pressure, if this is the case, is there any reason why i could not emulate what I understand to be the GS3 preinfusion on my junior by programming one of the buttons to deliver x ml and run a standard delay myself before hitting the double shot button?

Seamus

[AndyS]

I've just read through the Pro's Perspective on the GS3 and it crystallised a question a question I've been considering for some time.

Can anyone explain pump pulse preinfusion to me, my understanding is that it is a preinfusion based on reduced volume as opposed to reduced pressure, if this is the case, is there any reason why i could not emulate what I understand to be the GS3 preinfusion on my junior by programming one of the buttons to deliver x ml and run a standard delay myself before hitting the double shot button?

If you get the volume right it'll work pretty well. The difference is that using the Junior button, you'll build up a small amount of pressure, then you'll bleed it off when the three-way opens back up, then you'll pull the shot. The puck gets squeezed, then opens up, then gets slammed. It's not ideal.

Machines that are designed for pp pi keep the 3 way closed the whole time.

[tweeek]

ah yeah, bugger.

maybe I'll just focus on my distribution instead.....