Which type of valve is designed to prevent the collapse of a pipe?

The air-and-vacuum relief valve is specifically designed to prevent the collapse of a pipe by allowing air to enter the system when negative pressure occurs. When water is rapidly drawn from a pipeline, it can create a vacuum that may lead to pipe collapse due to external atmospheric pressure exceeding the internal pressure. The air-and-vacuum relief valve opens to admit air into the pipeline, breaking the vacuum and thus protecting the structural integrity of the pipe. This function is crucial in maintaining a stable pressure within the water distribution system and preventing potential damage to the infrastructure.

In contrast, check valves are used to prevent backflow in the system; ball valves are primarily used to isolate sections of pipe or control flow; and globe valves are mainly utilized for throttling flow rather than protecting against vacuum conditions. Understanding the distinct functionalities of these valves reinforces why the air-and-vacuum relief valve is the appropriate choice for preventing pipe collapse.