Which component is essential for preventing backflow in a multi-pump vacuum system?

In a multi-pump vacuum system, a check valve is crucial for preventing backflow. This device allows fluid or gases to flow in only one direction, effectively maintaining the integrity of the system by stopping any reverse flow that could disrupt the operation of the pumps.

When multiple pumps are involved, especially in applications where they may share pipelines or chambers, backflow can lead to contamination, loss of vacuum, or damage to the equipment. The check valve serves as a safeguard against these issues by ensuring that once the gas or fluid has passed through the valve, it cannot flow back, thus providing a reliable and efficient vacuum system operation.

The other components mentioned do not serve the same function as the check valve. A blind flange is typically used to close off a pipeline or vessel, a manual valve allows for user-controlled flow regulation which does not inherently prevent backflow, and a grooved joint is a type of connection used in piping systems that does not address issues of directional flow.