Final answer:
Regulator adjusting screws should be loosened before opening cylinder valves to avoid damaging the regulator and to maintain controlled gas release for safety and system integrity.
Step-by-step explanation:
The regulator adjusting screws must be turned out until loose before opening the cylinder valves to prevent regulator damage and ensure safe operation. When the cylinder valve is opened, the high pressure within the cylinder could potentially cause rapid pressurization of the regulator. If the adjusting screws are not loose, the sudden impact of high pressure could damage the regulator mechanism. Moreover, easing into the appropriate pressure levels by loosening the adjusting screws first helps in the controlled release of gas, which is essential for both the safety of the operator and the integrity of the system.