To reduce pressure to an acetylene regulator, the adjusting screw is turned:

To reduce pressure to an acetylene regulator, the adjusting screw is turned:

• A. Counter-clockwise until the tension is off
• B. Clockwise to its limit
• C. Clockwise one full turn
• D. Clockwise one half turn

Answer: (A)

The adjusting screw on a regulator changes the force the spring applies to the diaphragm, which sets the output pressure. Turning the screw clockwise tightens the spring and increases the regulated pressure, while turning it counterclockwise loosens the spring and decreases the pressure. To reduce the pressure to the acetylene regulator, back the adjusting screw off in the counterclockwise direction, relieving spring tension until you reach the desired lower pressure. The other options would push the pressure higher, not lower, since they involve turning the screw clockwise. After adjusting, check the gauge and ensure the pressure is within the safe working range.

The adjusting screw on a regulator changes the force the spring applies to the diaphragm, which sets the output pressure. Turning the screw clockwise tightens the spring and increases the regulated pressure, while turning it counterclockwise loosens the spring and decreases the pressure. To reduce the pressure to the acetylene regulator, back the adjusting screw off in the counterclockwise direction, relieving spring tension until you reach the desired lower pressure. The other options would push the pressure higher, not lower, since they involve turning the screw clockwise. After adjusting, check the gauge and ensure the pressure is within the safe working range.