What can happen if water is too hot in the open feedwater heater?

In an open feedwater heater, the purpose is to preheat the feedwater before it enters the boiler, which improves overall thermal efficiency. If the water temperature in the open feedwater heater becomes excessively high, it can lead to the phenomenon of being "steambound." This occurs when steam enters the feedwater pump instead of just water. This situation can drastically affect the pump's operation, as it is designed to handle liquid water and not steam.

When steam enters the pump, it can result in cavitation or insufficient flow to the boiler, causing various failures in the system. This issue highlights the importance of proper temperature control in feedwater heaters to ensure that the feedwater remains in the liquid state, allowing the pump to function efficiently and maintain a steady flow to the boiler. Maintaining optimal temperature prevents operational problems that can arise when steam is inadvertently introduced into the feedwater system.