MCC-NH Gas Fitters Practice Exam

How can you isolate appliances not included in a pressure test?

1. By removing them from the system

2. By disconnecting and capping the outlets

3. By adjusting the pressure settings

4. By installing additional valves

The correct answer is: By disconnecting and capping the outlets

The correct approach to isolate appliances not included in a pressure test is to disconnect and cap the outlets. This method effectively prevents any gas from flowing to those appliances, thereby ensuring that the pressure test only evaluates the integrity of the piping leading to the remaining appliances. By capping the outlets, you create a sealed system that allows for accurate pressure measurement without interference from the untested appliances. In contrast, other options do not adequately address the need for isolation. Simply removing appliances from the system may not be practical or feasible, as it could disturb existing connections or require significant disassembly. Adjusting the pressure settings does not isolate appliances; it only changes the parameters of the test, which could lead to misleading results. Installing additional valves could be cumbersome and may not provide a temporary solution for a pressure test; it is better to use the existing system to isolate the appliances effectively. Thus, disconnecting and capping the outlets is the most straightforward and reliable method for achieving proper isolation during a pressure test.