- always properly secure the cylinders
- while standing to one side, momentarily open the valve to clear any dirt present before
connecting a regulator
- after connecting the regulator, release the pressure-adjusting screw and then slowly open
the cylinder valve to prevent a high-pressure gas surge in the regulator
- always shut off the cylinder valve and back off the adjusting screw when the cylinder is
not in use
The cautions given above apply to all shielding gases, whether for use with the GMAW process or
other gas shielded processes (FCAW, MCAW, GTAW) discussed later. For more details on Welding
Safety, reference CSA Standard W117.2 “Code for Safety in Welding and Cutting (Requirements for
Welding Operators)” or Module 1, Welding Health and Safety, of the MLS series.