Which equipment is essential for safely connecting a propane appliance?

The correct choice highlights the importance of a flow regulator in safely connecting a propane appliance. A flow regulator is designed to control and maintain a consistent flow of propane gas from the tank to the appliance. It ensures that the gas is delivered at the appropriate pressure, which is crucial for the safe and efficient operation of the appliance.

If the pressure is too high, it can cause damage to the appliance or create a hazardous situation. Conversely, if the pressure is too low, the appliance may not function properly. Therefore, using a flow regulator helps to ensure that the propane is delivered in a safe, controlled manner, reducing the risk of leaks or failures.

While other equipment may have roles in the overall system (like monitoring pressure with a gauge or stabilizing pressure), the specific function of regulating the gas flow is what makes the flow regulator essential for the initial connection to a propane appliance.