Andrew, try it without any basket in place. My gauge does the same thing, though I have no idea why.

You're supposed to removed the basket.......DOH!

I tried this today with some parts from the local hardware. I was surprised to find water squirting out around the top of the basket rather than sealing up.

That's because brew pressure is also being applied between the inside of the PF and the basket. The "seal" between the underside of the basket lip and the PF is not pressure-tight because, under normal circumstances, it does not need to be. When you do run this w/o a basket, tighten the basketless PF JUST ENOUGH to stop any gross leakage. While the top surface of the PF is certainly not a knife-edge, it is far less kind to the grouphead gasket than the smooth basket lip.

You need to run this test without a basket.

andrewpetre wrote:I tried this today with some parts from the local hardware. I was surprised to find water squirting out around the top of the basket rather than sealing up.

This does not happen with the same handle when I use the blind filter. With the backflush (blind) basket inserted, it locks up tight when the pump is turned on, as I would expect.

Any idea why a standard basket would gush around the seal gasket in this particular application?

Also no leakage issues when brewing. If I choke the machine, it locks up tight - I never get any weird spillage like this.

I realize that the obvious answer is a hardened group gasket that could be replaced, but there are no similar issues when brewing or backflushing.

This is on an older Silvia.

ap

I had this issue at first - putting in the basket only made the leaks worst. When I re-did the tests this evening I was somehow able to turn the PF a little further and there were no leaks.

I'm still having trouble getting my head around adjusting the OPV for 60mil in 25 seconds. With the standard for a single shot basket being 30mil in 25 seconds, to my way of thinking the OPV pressure would be adjusted to suit the single basket. The double basket being made to a larger capacity and with more holes would then give the required 60 mil per 25 sec at the same pressure. I certainly respect those who share their experience with us here I'm just having trouble understanding this flow rate bit.

I certainly respect those who share their experience with us here I'm just having trouble understanding this flow rate bit.

If you read the info in this link (from my post - several above), it will help: WBC Procedure for Measurement of Brewing Water Temperature. See section 4.3

But that relates to measuring the brew temp, I will do some more research on OPV adjustment at a later date to set my mind at ease.

Thefly,

Can you tell me what is the fitting thread on Rancilio Silvia portafilter? It seems you have a perfect fit with this setup.

I'm looking to build one for and I don't want to damage the threads so I could toggle with gauge and double spout on my Rancilio PF.

Thanks,

Deny

It is 1/4 Male NPT

And you can forgo with the additional fittings to allow a water flow. What I know have is a 1/4 Male NPT elbow coming off the PT to a 1/4 MNPT reducing adapter to the gauge. This is then a blind gauge which I have set to 9.0 BAR (which equates to 8.6 BAR at puck). Best to take PF with you to store and fit pieces.

Better recheck your measurements - it is a 3/8-19 BSP (British Standard Pipe) thread. The US equivalent is, of course, a 3/8-18 NPT thread. While yes, there is a small difference in thread pitch, thread shape, and thread OD, 3/8" US pipe thread fittings will work just fine with a couple of wraps of teflon tape on the PF threads. I'm not too sure whether the British threads are tapered or parallel but at the short length they have, it does not matter.

A good way (emphasis on "A") to build the PF gage is to screw a 3/8" street tee onto the PF and screw a 3/8" to 1/4" reducing bushing into the side outlet for your 0-300 psi oil-filled gage - http://www.gaugestore.com/prodinfo.asp?number=38305. Use brass fittings and two wraps of teflon tape on all of the male threads is sufficient. The bottom male thread on the tee can be capped off for future adventures. Yes, I have seen in previous posts where the use of a "non-filled" gage on a vibration pump machine has apparently worked with little or no needle flutter but the difference in cost between these gage attributes is small. Use a gage that has a known pedigree - yes it costs a little more but you will thank yourself.