Tweco ArcMaster 401MST - Manual (Page 54)

ARCMASTER 401MST POWER SOURCE
INSTALLATION, OPERATION AND SETUP 3-24 Manual 0-5287
NOTE
The flowmeter/ regulator used with argon based and carbon dioxide shielding gases are different. The
flowmeter/ regulator supplied is for argon based shielding gases. If carbon dioxide is to be used a
suitable carbon dioxide flowmeter/ regulator will need to be fitted.
NOTE
All valves downstream of the flowmeter/ regulator must be opened to obtain a true flow rate reading
on the outlet gauge. (Welding power source must be triggered) Close the valves after the pressure
has been set.
Installation
1. Remove cylinder valve plastic dust seal. Clean the cylinder valve outlet of impurities that may clog orifices
and damage seats before connecting the flowmeter/ regulator.
Crack the valve (open then close) momentarily, pointing the outlet away from people and sources of ignition.
Wipe with a clean lint free cloth.
2. Match flowmeter/ regulator to cylinder. Before connecting, check that the flowmeter/ regulator label and
cylinder marking agree and that the flowmeter/ regulator inlet and cylinder outlet match. NEVER CONNECT
a flowmeter/ regulator designed for a particular gas or gases to a cylinder containing any other gas.
3. Connect the flowmeter/ regulator inlet connection to cylinder or pipeline and tighten it firmly but not
excessively, with a suitable spanner.
4. Connect and tighten the outlet hose firmly and attach down-stream equipment.
5. To protect sensitive down-stream equipment a separate safety device may be necessary if the flowmeter/
regulator is not fitted with a pressure relief device.
Operation
With the flowmeter/ regulator connected to cylinder or pipeline, and the adjustment screw/knob fully disengaged,
pressurize as follows:
1. Stand to one side of flowmeter/ regulator and slowly open the cylinder valve. If opened quickly, a sudden
pressure surge may damage internal flowmeter/ regulator parts.
2. With valves on downstream equipment closed, adjust flowmeter/ regulator to approximate working pressure.
It is recommended that testing for leaks at the flowmeter/ 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 flowmeter/
regulator by individually opening then closing the equipment control valves. Complete purging may take
up to ten seconds or more, depending upon the length and size of the hose being purged.
Adjusting Flow Rate
Figure 3-13 Adjust Flow Rate