The discharge side valve of a cargo pump on a tank vessel is typically a?

The discharge side valve of a cargo pump on a tank vessel is typically a check valve because its primary function is to prevent backflow within the system. When cargo is being pumped from the tank, the check valve enables the flow in one direction—out of the pump and into the discharge line. If the pump were to shut down or if there were a drop in pressure, the check valve automatically closes to stop any reversal of flow, thereby preventing contamination of the cargo and ensuring system integrity.

The design of a check valve is particularly suitable for this application because it requires no manual operation and responds automatically to pressure changes. This characteristic is essential in tanker operations, as even slight backflow can lead to operational hazards or cargo loss.

Other types of valves mentioned have different functions. For instance, a butterfly valve is primarily used for flow regulation but can also be used in on/off applications; however, it does not prevent backflow as effectively. A globe valve, while good for throttling flow, is generally not ideal for applications where backflow prevention is key. Similarly, a gate valve is best suited for fully open or closed positions but lacks the inherent backflow prevention advantage offered by a check valve.