What must be ensured regarding the plastic washer during a gas system setup?

Ensuring that the plastic washer is seated properly is crucial for the safe and effective operation of a gas system. When the washer is correctly positioned, it creates a secure seal between the gas tank and the regulator, which prevents gas leaks. A proper seal is essential not only for maintaining system pressure but also for ensuring the safety of personnel and equipment by avoiding potentially hazardous leaks of gas. Misalignment or improper seating of the washer can lead to dangerous situations where gas may escape, posing risks of fire or asphyxiation. Therefore, the integrity of the connection relies heavily on the plastic washer being seated properly during setup.