What is true about the flow direction of a pipe union?

A pipe union is a fitting that allows for the connection and disconnection of two pipes while maintaining a leak-proof seal. The correct answer highlights that pipe unions typically have a designated flow direction. This is significant because the design of the union, including its internal geometry, can influence how fluid moves through the system. If the union is designed with a specific orientation to streamline flow or reduce turbulence, it must be installed in the correct position to function as intended.

In certain applications, such as with valves or specific types of joints, maintaining the proper flow direction ensures optimal performance and prevents issues like cavitation or backflow, which can damage the system or affect efficiency. The other options suggest alternate interpretations about flow that might not apply universally to all pipe unions, making a deep understanding of the specific union type and flow dynamics crucial for maintaining system integrity.