What must be done to a pipe system before a pressure test is initiated?

Ensuring all valves are closed is crucial before initiating a pressure test on a pipe system. This step prevents any unintended release of air or fluid during the test, which could compromise the accuracy of the test results and potentially lead to safety hazards. When valves are closed, the system is contained, allowing for a controlled environment where the integrity of the pipe and fittings can be assessed under pressure.

Closing the valves also helps to isolate sections of the piping, making it easier to identify any potential leaks or weaknesses within the system. If valves were left open, the pressure test could fail to accurately indicate whether there are any leaks or weak points due to variations in pressure created by fluid or air escaping.

In contrast, removing fittings, emptying the system of liquids, and inspecting for leaks, while all important maintenance practices at different stages of piping installation or maintenance, do not directly address the necessity of stabilizing the system for a pressure test. These steps may be part of a broader maintenance or safety procedure but are not specifically required just before conducting a pressure test.