What is the purpose of a vent on an open feedwater heater?

The purpose of a vent on an open feedwater heater is to remove air and other non-condensable gases from the system. In steam systems, the presence of air and non-condensable gases can lead to a range of issues, including reduced efficiency, corrosion, and potentially damaging water hammer phenomena. By venting these gases, the open feedwater heater ensures that the water entering the system is free from contaminants that could hinder the heat transfer process.

Removing these gases is crucial because they can create insulating layers on heat exchange surfaces, reducing the heater's efficiency. Additionally, accumulated air could lead to inadequate heating of the water, and in some cases could cause significant operational problems if trapped. Thus, a properly functioning vent is essential to maintain the overall efficiency and safety of the steam system.