jason_casale wrote:I bought a e61 manometer gauge put together complete with the portafilter from a known vendor we all know to get an idea what the pressure was from the group head compared the manometer gauge for pressure from the linea. It was about 1 bar difference between the 2 still helpful information and those portafilter manometers are like gold everyone should have one and most machine techs you will find do own them. Between that and my scace and fluke meter I am set. Good investment on your part if your machine does not have a pump pressure gauge.

Jason,

You say the 2 gages weere off by ~1 bar. Was the PF gage the higher? Does "pressure from the linea" mean pressure from the line, i.e. the line from the pump as displayed by the machine mounted gage?

Len

Worldman wrote:Dave,

OK...it makes sense that the reading would be higher with a blocked PF vs. one with coffee grounds therein...though, in another sense I would think the readings should be the same since it is the pressure at which the OPV shunts the pressure side of the pump to wherever it goes. Pressure is what it is <---man, that IS an obvious statement. Still, there is a side of me that says that the pressure value would shift based on whether the resistance was a hard resistance (blocked PF) vs. a soft resistance (grounds in a basket).

In any event, I accept what you say as true. Should I then set my P-stat to allow ~9.5 bar on the PF gage?

Len

That is what works best for me, your mileage may vary. Different machines behave a little different, but I believe this is a relatively standard observation. I run my two machines at two different pressures. My Isomac works better with a little higher pressure while my Faema works best just a little lower. Vibe pump vs rotary, preinfustion vs no preinfusion etc.

In the end, your taste buds are all that matter. The over pressure valve is easy to adjust so you can make a change, pull a few shots (and taste them), make another change pull a few more shots, until you are happy with the results. You may want to call your local roaster and ask them what they have their machine set at and what their dose is. Use that as a starting point and play with the settings until you are happy with the cup. Keep in mind that as you change the pressure, you will need to change your grind so you can burn through some beans getting it set.

Len,

How did you make your steam wand boiler pressure gauge contraption?

Care to share?

VS,

Hello! The "wand mounted" pressure gauge is pretty simple and an idea I got on-line. It is an inexpensive tire pressure gauge + a 8" long piece of (IIRC) 1/8" rubber tubing + 2 hose clamps...all bought from a local NAPA auto parts store.

The whole cost me ~$10.

You simply open the steam valve and read the pressure with an HX machine. With a single boiler machine (such as Silvia) you will need to assure that the machine is up to steam pressure by switching the high temp element on and waiting as long as you would to start steaming.

Len

Thanks a lot, Len. I really appreciate it.

-Vince

Hi. I'm new to this forum. I have a Rancilio Silvia which i just PID'd. I also got a pressure gauge from 1st line, hooked it in to my porta filter with a standard basket in it and turned the brewer on. I got a reading of 10 bars, but the gauge also filled with water. Is that normal? Did I do something wrong? Thanks- Steve

Well, obviously it would fill with water since that's what you're pumping in there, or did it leak into the display part of the gauge? If you got that latter, it would show that your gauge is leaking, which is probable if you used an air pressure gauge. If you want really accurate measurements, get a water pressure gauge that's rated for boiling water. For the steam wand you would then need a steam pressure gauge. Technically I don't think they measure any different, it's more what kind of operating conditions they are capable of withstanding.

Hi Stuggi, and Thanks for the quick reply. I bought the Pump Pressure check kit from 1st Line Equipment, so i don't think it is an air pressure gauge. Water did leak into the display part, but upon further inspection when I unscrewed the gauge from the portafilter adaptor they provided, I found a scant and uneven application of teflon tape. So I'm thinking maybe the water leaked from that connection and into the housing of the gauge. I'll get some more tape tomorrow and see if that solves my problem. Cheers-- Steve