Vetrano Espresso Machine
13
Expansion Valve Adjustment
Warning:
This adjustment requires removing the shell and making an adjustment with the
machine plugged in so it is very important to exercise extreme caution. Failure to do so may
cause injury, and or electrical shock. Chris‟ Coffee Service and its distributors assume no
liability for failure to follow this warning.
The expansion valve is used to allow for the expansion of heated water in the heat
exchange. This water is discharged into the drip tray via a black plastic spout. During heat
up it is normal for the black plastic spout to discharge some steam and hot water into the
drip tray.
Before making an adjustment the machine should be
up to operating temperature.
After the machine is up to temperature follow the
instructions for setting the pump pressure and raise
the pump pressure to 12.5 bar.
Install the backflush disc into the portafilter and then
lock the portafilter into the group head.
Remove the drip tray cover and then raise the brew
lever. Use a 12mm or adjustable wrench to adjust
the expansion valve adjustment nut.
With the pump running adjust the expansion valve so
the black plastic spout in the drip tray just starts to
drip. Turning clockwise will slow the drip, counter
clockwise to increase.
Be sure the attached silicone hose does not get
twisted, straighten out if necessary.
After adjusting the expansion valve then adjust the pump pressure back down to 9 bar.
Note:
If the expansion valve continues to drip at 9 bar after adjustment then the rubber seat
inside the valve should be replaced. A replacement seat can be ordered from our website
here:
http://www.chriscoffee.com/products/home/parts/expansionvalveseat