Question 56

The Correct Answer is C ### Explanation for Option C (Correct Answer) The DC heater (Deaerating Condenser or Deaerator) automatic level dump valve is a control valve designed to manage the water level within the deaerator vessel. The deaerator's primary function is to remove dissolved gases (like oxygen and carbon dioxide) from the feedwater before it enters the boiler. When the level inside the deaerator rises above a predetermined setpoint (indicating an excess of feedwater supplied by the low-pressure heaters or other sources), the automatic level dump valve opens. This valve is typically plumbed to **divert the excess feedwater** (which is now deaerated water) to a storage location, such as the **distilled water tank** (or often referred to as the storage tank, reserve feedwater tank, or surge tank). This action prevents the deaerator from flooding and maintains the necessary operating level. ### Explanation for Incorrect Options **A) divert the flow of condensate from the first stage heater to the vent condenser** This action describes the function of a drain regulator or level control valve associated with the low-pressure feedwater heaters, not the primary function of the DC heater's excess level dump valve. Furthermore, the flow being diverted from the heaters is usually heater drains (condensed steam), not the primary feedwater flow. **B) maintain a proper condensate level in the condenser hotwell** This function is handled by the **Makeup Valve** and the **Condensate Pump Recirculation Valve (or Excess Condensate Valve)**, both controlled by the hotwell level control system. The DC heater level dump valve operates entirely independently of the main condenser hotwell level control. **D) recirculate condensate to the atmospheric drain tank** While the atmospheric drain tank sometimes receives excess water or drains, the deaerator level dump valve typically directs excess deaerated feedwater to a reserve storage tank (like the distilled water or surge tank) for later use. Recirculating it to the atmospheric drain tank would often violate best practices for maintaining treated water inventory.