Tweco GCM-6000 Gas Control - Manual (Page 28)

OPERATION 22 Manual 0-2641
9. Place the MODE switch to the RUN position.
NOTE
When switching gases between operations, allow
enough purge time to clear the old gas from the
torch leads. Pilot, plasma and secondary gases are
purged separately by switching to PILOT SET,
PLASMA SET and SEC SET.
B. Operations With Optional Gas/Water Flow
Control, using CONVENTIONAL PLASMA
process (i.e. non-Square Cut)
1. Set GAS switch on the Optional Secondary Gas/Wa-
ter Flow Control to the HIGH-FLOW position
2. Perform all other steps as shown above in Section
4.04-A.
C. Operations With Optional Gas/Water Flow
Control Using Gas Secondary Flow
Control.
NOTE
Gas Secondary Flow Control is used only for the
Square Cut Process using oxygen (O
2
) gas as the
plasma and secondary.
1. Connect the required gas supplies (or water for sec-
ondary water) to the correct plasma and secondary
inlets on the Master Power Supply. Connect the oxy-
gen (O
2
) secondary gas to the OTHER secondary inlet
connection for this application Refer to the Master
Power Supply Operating Manual, 0-2652, to make
connections.
2. Turn ON the gas supplies.
3. Set the gas bottle regulators, if used, to the proper pres-
sure and check for leaks.
NOTE
While nothing prevents the operator from switch-
ing gases during piloting or cutting it is not rec-
ommended to do so. It may cause pressure or flow
fluctuations that may damage torch parts or the
piece being cut.
4. Refer to the Operating Manual supplied with the Power
Supply and turn ON power to the Power Supply.
5. Select the desired oxygen (O
2
) plasma and oxygen (O
2
)
secondary gases by setting the Gas Control Module
front panel switches to the desired(O
2
Plasma and
OTHER Secondary) gas positions.
6. To set the preflow gas pressure and flow rate do the
following (see NOTE):
NOTE
Preflow is set only when using oxygen (O
2
) plasma
gas. For all other plasma gases DO NOT do this
step.
a. Set the MODE switch to PILOT SET.
b. Fully open the valve on the top of the PREFLOW
flowmeter.
c. Pull out the knob on the PREFLOW regulator.
d. Turn the knob clockwise to increase or counter-
clockwise to decrease gas pressure.
e. Push the knob back in to lock the pressure setting.
f. Slowly close the valve on the top of the PREFLOW
flowmeter until the desired flow rate is achieved.
7. To set the plasma gas pressure and flow rate do the
following:
a. Set the MODE switch to PLASMA SET.
b. Fully open the valve on the top of the PLASMA
flowmeter.
c. Pull out the knob on the PLASMA regulator.
d. Turn the knob clockwise to increase or counter-
clockwise to decrease gas pressure.
e. Push the knob back in to lock the pressure setting.
f. Slowly close the valve on the top of the PLASMA
flowmeter until the desired flow rate is achieved.
8. To set the secondary gas pressure do the following:
a. Set the Optional Secondary Gas Flow Control
GAS switch to the LOW-FLOW position.
b. Set secondary gas selector switch to OTHER
c. Set the MODE switch to SECSET
d. Fully open the valve on the top of the secondary
flowmeter
e. Pull out the knob on the SECONDARY regulator.
f. Turn the knob clockwise to increase or counterclock-
wise to decrease gas pressure.
g. Push the knob back in to lock the pressure setting.
h.. Slowly close the valve on the top of the secondary
flowmeter until the desired flow rate is achieved.
9. Place the MODE switch to the RUN position.