In-line check valves are not required to have what feature?

In-line check valves play a crucial role in preventing backflow within a piping system, particularly in medical gas applications. One essential aspect of these valves is their design, which can include various features to ensure functionality and ease of use.

The chosen answer indicates that threaded end connections are not a requirement for in-line check valves. This is correct because these valves can be designed with different types of connections, including flanged or welded joints, rather than being restricted solely to threaded connections. The choice of connection type often depends on the specific application or installation requirements.

For instance, while threaded connections provide ease of installation and removal, they are not mandatory for in-line check valves, as these valves can also be effectively integrated with other connection types. Therefore, manufacturers might design check valves without threaded end connections to accommodate particular system specifications or preferences in installation practices.

In contrast to threaded end connections, features like brazed extensions, in-line serviceability, and threaded purge ports may be more consistently incorporated into the design of check valves. Brazed extensions can be necessary for certain applications to help facilitate installation. In-line serviceability is an important feature that allows for maintenance without disrupting the entire system, and threaded purge ports are essential for cleaning or flushing the system. These features enhance