What guidelines are established for main propulsion boilers to reduce feedwater consumption on steaming boilers?

The correct choice is to dump, as it refers to a practice where excess water is removed from the boiler to maintain operational efficiency. Dumping typically involves releasing a portion of the feedwater that may be saturated with impurities or contaminants, which, if left in the system, can lead to scaling and increased feedwater consumption due to inefficiencies in heat transfer.

By regularly dumping excess water from the system, it helps to maintain the overall water chemistry within acceptable limits, thereby avoiding the need for additional feedwater to compensate for contamination or imbalances. This method can also support maintaining boiler performance and efficiency by ensuring optimal water quality and preventing scaling, which directly contributes to reducing overall feedwater consumption.

In contrast, options like reducing steam pressure or maintaining a constant temperature might not effectively lower feedwater consumption, as these actions primarily influence operational parameters rather than directly addressing water quality and efficiency in the boiler system. Continuous blowdown, while it can aid in managing water quality, can sometimes lead to an increase in feedwater consumption if not managed correctly, as it entails the removal of water from the boiler during operation.