A lock up test measures the pressure in the lines downstream of the first stage regulator to ensure that the regulator will shut off the flow of propane when the appliances are not calling for gas.

A lock up test measures the pressure in the lines downstream of the first stage regulator to ensure that the regulator will shut off the flow of propane when the appliances are not calling for gas.

• A. Not applicable
• B. Sometimes
• C. True
• D. False

Answer: (C)

The test checks whether the first-stage regulator will stop feeding gas when appliances aren’t calling for it. In a lock-up test, you monitor the pressure downstream of that regulator with all appliance valves closed and no demand. If the system is functioning properly, the downstream pressure should drop to essentially zero, showing the regulator has sealed off and is not delivering gas when not needed. This confirms the regulator’s shut-off capability, which is crucial for preventing gas leakage when there’s no demand. If pressure stays on the downstream side, it suggests a fault in the regulator or a leak path, meaning gas could continue to flow when it shouldn’t. So the statement is true.

The test checks whether the first-stage regulator will stop feeding gas when appliances aren’t calling for it. In a lock-up test, you monitor the pressure downstream of that regulator with all appliance valves closed and no demand. If the system is functioning properly, the downstream pressure should drop to essentially zero, showing the regulator has sealed off and is not delivering gas when not needed. This confirms the regulator’s shut-off capability, which is crucial for preventing gas leakage when there’s no demand. If pressure stays on the downstream side, it suggests a fault in the regulator or a leak path, meaning gas could continue to flow when it shouldn’t. So the statement is true.