I have read there are 2 pressure adjustors with the Rocket: 1. is by turning a screw on the Sirai pressurestat, 2. the pressure of the rotary pump is adjustable.
Perhaps they don't both control the pressure at the group head, or perhaps one faces a choice as to which to adjust - can someone please explain?

Mark

The Sirai pressurestat controls the steam boiler pressure; it's typically in the range of 1.0 to 1.2 bar. See How to adjust an espresso machine pressurestat for details.

The rotary pump controls the brew pressure; it's typically in the range of 8.0 to 9.5 bar. The pump pressure is adjusted via the bypass valve (#22 below). Turning it clockwise increases pressure, counter-clockwise reduces pressure. It's a sensitive adjustment, so turn no more than 1/4 turn before checking the brew pressure. Searching on "rotary pump pressure" found related discussions.


Fluid-o-Tech rotary pump; Procon pumps have similar adjustment

Hi Dan,
Sounds like the pressure gauge indicate steam pressure? It is not working which I why I have started working on it.
My Giotto has a vibrating pump model. Do you happen to know where / if I can adjust brew pressure with this pump, and do you know of a brew pressure gauge that can be attached permanently to the machine?
Cheers
Mark

See How can I adjust the brew pressure of a vibe pump espresso machine? If the onboard brew pressure gauge isn't working, use a portafilter with pressure gauge on it. Threads like Building a Portafilter Pressure Gauge show what others have cobbled together from hardware store parts.

Dan

I only have 1 gauge on my Giotto - I guess this does not provide brew pressure does it?

Mark

Correct. It isn't uncommon for an espresso machine to have only the steam pressure gauge (ECM Giotto, La Valentina, Elektra Semiautomatica, Cimbali Junior, to name only a few). The dead giveaway which is which is the gauge's range; around 0 to 2 bar for steam pressure, 0 to 15 bar for brew pressure.