YEP... For some unknown reason (to me) there is two slots cut across the lip of the PF as provided with the new BZ99

For a blind it does not matter as no water in the bottom of the PF.

With coffee and a normal basket... The pressure is on top and the good oils flow through and out the spouts..

With a gauge attached to the spout and either a restricted flow or the spout blocked off then;

1: the water flows into the PF and then as pressure builds up in the PF.

2: The water flows all around the inside and the underside of the basket as the pressure builds.

3: It then finds these two slots and as an escape path and sprays water every where.

Needless to say trying to get a reading via a fitting from the spout with a standard BZ99 PF is a waste of time. Have also been unlucky as the other 5 PF I have come close but do not fit correctly. I guess I just have to keep trying.

But can any one provide an answer or a theory as to why the PF has these two slots cut into the lip ?

AngerManagement wrote:Needless to say trying to get a reading via a fitting from the spout with a standard BZ99 PF is a waste of time. Have also been unlucky as the other 5 PF I have come close but do not fit correctly. I guess I just have to keep trying.

remove the basket and use the pressure gauge without a basket. It'll seat funny, but that's how to make it work.

(note - not sure about the slots; it might still be an issue, but it might work, depending on how it seals against the group gasket. I *THINK* mine has the slots too - I'll have to check; they might be to ease getting the basket out)

AngerManagement wrote:But can any one provide an answer or a theory as to why the PF has these two slots cut into the lip ?

To allow air to enter under the lip and thereby avoid an occasional glub glub glub. Think of pouring water out of a plastic jug by turning it upside down versus turning it upside down and poking a hole in the bottom. The water will pour out more evenly in the latter case.

Thanks Dan and allon...

There is some agreement re the slots and to act as a relief / vent... But if it was critical, one would expect to see it else where, thus why ?

And if it did make a difference to the cup, what not then market the feature. But could find nothing on it. Mind you google it not always able to find exactly what you want / ask for.

Allon, if you don't use a basket.... Then teh slots are deep enough that the lip would need to bite at least 4mm into the group seal...

I think I will just need to did out another 4 or 5 PF and try them all. ONE MUST FIT

Mark

AngerManagement wrote:There is some agreement re the slots and to act as a relief / vent... But if it was critical, one would expect to see it else where, thus why ?

Maybe it was considered important during the days of Robusta-laden bar blends that produced mountains of crema (?). IIRC, the older Rancilio commercial portafilters had a slot, but newer ones don't. *shrug*