its 01:48 and I’m just back from a LONDINIUM II install. and hour and a bit of perfect driving back to london on a cloudless, moonlit autumn night is the perfect ending
this installation had higher water pressure than i was expecting, 6.5bar, which meant the cold water fed heat exchangers on the LONDINIUM II were causing the coffee to run from the portafilter in less than 2 seconds even when the grind & dose we spot on – in short it was acting like a pump machine as the low pressure pre-infusion was being denied by the high inlet pressure
so i installed the above pressure reducing valve from Honeywell which works like a charm – the green knob is used to adjust the pressure reducing effect of the valve up or down. i set it to 3 bar
if you do have high water pressure, i.e. more than 6 bar a pressure reducing valve must be installed as it places too much load on the solenoid inlet valve, to the extent that it may cause it to malfunction