What is the requirement for a check valve during a leakage test?

The requirement for a check valve during a leakage test centers on its ability to maintain integrity under test conditions over a specified duration. The stipulation that the check valve must be able to withstand 16 hours without leakage is critical because this duration ensures that the valve can effectively hold back the fluid and prevent any leaks, which is fundamental in applications involving water wells. A leakage during this test might indicate a failure in the valve, which could lead to potential contamination of the water supply or loss of water pressure, compromising the system's efficiency and safety.

In contrast, the other criteria do not adequately ensure the check valve's functionality in a realistic operational context. A requirement for 1 minute might not realistically reflect how the valve would perform over an extended period during actual use. Similarly, testing at half the rated working pressure or merely at ambient temperature does not provide a complete picture of the valve’s reliability under operating conditions that may vary significantly in real-world applications. Therefore, the long duration of 16 hours is significant for ensuring the check valve’s durability and effectiveness in preventing leakage.