Graco PR70 Operation & Maintenance Manual page 27

Options Screens
Fluid Options, Screen #1
HB
HA
HC
HD
HE
HK
HL
HM
HN
HW
Key:
HA Enter/Exit Screen
HB Purge Timer Enable/Disable
HC Purge Timer Delay
HD Purge Timer Shot Size
HE Purge Timer Alarm (seconds)
HF Recirculation Timer Enable/Disable
HG Recirculation Timer Delay
HH Recirculation Timer Shot Size
HJ Recirculation Timer Alarm (seconds)
HK Low Level Sensors Enable/Disable
(For FCMB Systems)
F . 14
IG
Recirculation and Purge Timers
To use Recirculation mode, 3-way ball valves must
be installed at the dispense head. Fluid lines must
be installed going from the ball valves back to the
tank.
When Recirculation mode is enabled, both recircula-
tion ball valves must be turned to return material
back to the tank. Only turning one valve may result in
a pressure imbalance exceeding the machine's max-
imum working pressure.
312759W
HS HS
HR
HL Tank A High Level Sensor Options
HM Tank B High Level Sensor Options
HN Maximum Fill Time
HR Active Screen Name
HS Adjacent Screen Names
HT Active Screen Number
HU Adjacent Screen Numbers
HV Pressure Units of Measure Selection
HW Low Level Alarm Time
The Purge Timer and Recirculation Timer behave in a
similar way, with a certain shot size (HD, HH) being exe-
cuted after the timer delay (HC, HG) has elapsed. The
difference is that the purge timer operates with the dis-
pense valve open so a purge shot is executed. The
recirculation timer operates with the dispense valve
closed so when the shot is executed no material is dis-
pensed.
Both timers feature an adjustable alarm to warn the user
that the piston drive block is to begin moving. The alarm
setting is the number of seconds before the shot is to be
executed.
HF
HG
HU
HH
HJ
HT
HV
HU
Setup
27