Tweco GCM-6000 Gas Control - Manual (Page 29)

Manual 0-2641 23 OPERATION
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.
D. Operations With Optional Gas/Water Flow
Control Using Secondary Water
1. Connect the required plasma gas supply and second-
ary water to the correct plasma and secondary inlets
on the Master Power Supply. Refer to the Master
Power Supply Operating Manual, 0-2652, to make
connections.
2. Turn ON the gas supplies.
3. Set the gas bottle regulator, if used, to the proper
pressure and check for leaks.
4. Connect the secondary water inlet hose to a suit-
able water supply connection. Turn water supply on
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 plasma gas and secondary water by
setting the Gas Control Module front panel switches
to the desired 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 water flow rate do the following:
a. Set the MODE switch to SEC SET.
b. Adjust the secondary water flowmeter to the de-
sired flow rate.
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.