Tweco 350 4R Wirefeeder - Manual (Page 32)

4-8 Manual 0-5182
weldskill 250, 350 operation
Operation
5. To protect sensitive down-stream equipment
a separate safety device may be necessary if
the regulator is not fitted with a pressure relief
device.
Operation
With the regulator connected to cylinder or pipeline,
and the adjustment screw/knob fully disengaged,
pressurize as follows:
1. Stand to one side of regulator and slowly open
the cylinder valve. If opened quickly, a sudden
pressure surge may damage internal regulator
parts.
2. With valves on downstream equipment closed,
adjust regulator to approximate working pres-
sure. It is recommended that testing for leaks
at the regulator connection points be carried
out using a suitable leak detection solution or
soapy water.
3. Purge air or other unwanted welding grade
shielding gas from equipment connected to
the regulator by individually opening then
closing the equipment control valves. Com-
plete purging may take up to ten seconds or
more, depending upon the length and size of
the hose being purged.
Adjusting Flow Rate
Art: A-05088_AB
Figure 4-5 Adjust Flow Rate
With the regulator ready for operation, adjust working
flow rate as follows:
1. Slowly turn adjusting screw/knob in (clock-
wise) direction until the outlet gauge indicates
the required flow rate.
NOTE
It may be necessary to re-check the shield-
ing gas regulator flow rate following the
first weld sequence due to back pressure
present within shielding gas hose as-
sembly.
2. To reduce flow rate, allow the welding grade
shielding gas to discharge from regulator by
opening the downstream valve. Bleed weld-
ing grade shielding gas into a well ventilated
area and away from any ignition source. Turn
adjusting screw counterclockwise, until the
required flow rate is indicated on the gauge.
Close downstream valve.
Shutdown
Close cylinder valve whenever the regulator is not in
use. To shut down for extended periods (more than
30 minutes).
1. Close cylinder or upstream valve tightly.
2. Open downstream equipment valves to drain
the lines. Bleed gas into a well ventilated area
and away from any ignition source.
3. After gas is drained completely, disengage
adjusting screw and close downstream equip-
ment valves.
4. Before transporting cylinders that are not se-
cured on a cart designed for such purposes,
remove regulators.