Recreational Vehicle (RV) Technician Practice Test

What could be a consequence of foreign material in a propane regulator?

1. Decreased system pressure

2. Increased system pressure after lockup

3. Reduced flow of propane

4. Intermittent gas flow

The correct answer is: Increased system pressure after lockup

In assessing the impact of foreign material in a propane regulator, it's important to understand how these components function. A propane regulator is designed to control and maintain the pressure of propane within an RV's system. When foreign materials, such as dirt or debris, infiltrate the regulator, they can disrupt its normal operation. One of the potential consequences of this contamination is increased system pressure after it reaches lockup. Lockup refers to the point at which the regulator has reached its maximum output pressure and is no longer allowing fuel to flow, effectively shutting off the gas. If foreign materials are present, they may prevent the regulator from functioning correctly, leading to a situation where the pressure increases despite the lockup condition. This scenario can pose serious safety risks, as excessive pressure can cause hoses and fittings to rupture, leading to propane leaks and potential fire hazards. Other options could suggest different problems, such as decreased pressure, reduced flow, or intermittent gas supply. However, the unique functioning of a regulator and the effects of debris specifically lead to the scenario where pressure can unexpectedly rise in the system after lockup.