Recreational Vehicle (RV) Technician Practice Test

An LP regulator must have a rated capacity that equals or exceeds what measurement?

1. The length of the propane line

2. The total BTU input of all appliances

3. The size of the propane tank

4. The maximum operating temperature

The correct answer is: The total BTU input of all appliances

The correct answer is that an LP regulator must have a rated capacity that equals or exceeds the total BTU input of all appliances. This is because the regulator's primary function is to control the flow of propane from the tank to the appliances, ensuring that each appliance receives the right amount of gas at a steady pressure for efficient operation. If the regulator's capacity is inadequate, it may not be able to supply sufficient propane to meet the demands of all the appliances simultaneously, potentially leading to performance issues such as flame instability or insufficient heating. In contrast, the other options, while relevant to the overall system, do not directly dictate the regulator's capacity. The length of the propane line can affect pressure drop and delivery efficiency but is not a direct measure of the regulator's rated capacity. The size of the propane tank pertains to how much fuel is available rather than how much can be regulated for use at any given moment. The maximum operating temperature is a concern for materials and safety but is not a factor in determining the required capacity of the LP regulator itself.