Steel wool lightly rubbed over the regulator stem fitting before making the cylinder valve to regulator connection can be used to remove any burrs to improve seating of the fitting. Assure regulator is appropriate for the compressed gas. Not all regulators are interchangeable. Toxic and flammable gas regulators should never be used on an inert gas, damage to valve and potential violent reaction may occur. Assure regulator is appropriate for service pressure.
Pressure adjusting handles turn counterclockwise to decrease the pressure.
Connect regulator to valve opening. Hold the regulator body in your left hand and hold in-line with the valve outlet. When the two are aligned, and the regulator is seated in the valve outlet, begin to hand tighten with your right hand. Do not over-tighten. This is to minimize potential hazards.