GEA Grasso - Operating Position of Valves; Fig. 3: Stop Valve Opened; Fig. 4: Stop Valve Closed; Fig. 5: Check Valve

OPERATING INSTRUCTIONS
CO
2
/NH
3
CASCADE UNIT
250 - 1000 KW
_551511_om_kas_gbr_1_.doc 17
5. Check the system again for leakages.
Caution!
6. Start the compressor.
Flow direction: from A to B and C
7. Open the reservoir valve.
8. Draw refrigerant into the circuit at a low
compressor delivery rate.
stop valve
Valve opened during normal operation
At the same time, continuously check the weight
change in the filling cylinder.
Warning!
fig. 3: Stop valve opened
Only fill the quantity specified,
otherwise there is risk of
overcharging the circuit.
Valve closed during normal operation
9. Close reservoir valve when the suction pressure
nears the required values. Let the compressor
continue to run until the refrigerant has been
completely distributed in the circuit. Based on
the values, you can now assess whether
additional refrigerant has to be charged or not.
fig. 4: Stop valve closed
Check valve
Check valve during normal operation
Hint!
If necessary, repeat the "refrigerant
charging" process until the suction
pressure reaches the required value.
fig. 5: Check valve
10. After the charging process has been completed,
close the charging valve and cylinder valve.
Combined stop/ check valve
Combined stop/check valve opened during normal
operation
11. Drain and dismantle the charging line.
Now lift the hose to make liquid refrigerant flow
back into the cylinder.
Before dismantling the charging line, carefully
drain the gaseous contents of the hose into a
water receiver in accordance with the safety
regulations.
fig. 6: Combined stop/ check valve
Control valve
Small quantities of refrigerant gas may escape.
Control valve adjusted at:
1.6.2.9 Operating position of valves
— Commissioning
For the positions of the manually controllable fittings
for the operation of the CO
— changed operating conditions
/NH
2 3
-cascade unit see
P&I diagram.
The layout and symbols used in the R+I flow charts
comply with the specifications of EN 1861, Issue April
1998.
fig. 7: Control valve
Combined stop/ check valve with integrated
control function
Danger!
The valve positions must match the
specifications given in the R+I flow chart
to ensure trouble free operation!
Combined stop/ check valve with integrated control
function opened during normal operation
fig. 8: Combined stop/ check valve with integrated control
function