Recreational Vehicle (RV) Technician Practice Test

What is the maximum allowable lock-up pressure for any water column propane system?

1. 10 inches water column

2. 12 inches water column

3. 14 inches water column

4. 16 inches water column

The correct answer is: 14 inches water column

The maximum allowable lock-up pressure for any water column propane system is determined by safety and operational guidelines established for propane systems to ensure proper functioning and prevent dangerous overpressure conditions. A lock-up pressure is the maximum pressure that a propane regulator can maintain before it shuts off or stops allowing gas to flow. In the case of water column measurements, the standard maximum lock-up pressure indicated here is 14 inches of water column. This value is critical because it allows the system to function efficiently without the risk of over-pressurization, which can lead to leaks, malfunctions, or even explosive situations in severe cases. The other values—10 inches, 12 inches, and 16 inches—either fall below or exceed the maximum permissible limits defined in safety regulations for propane systems. While they may be appropriate for specific applications or types of equipment, they do not represent the correct maximum lock-up pressure. Keeping to the established maximum of 14 inches helps ensure the safe and reliable operation of propane systems in various settings.