🔍 Key Concepts

• Function of a DC (de-aerating) heater in the feedwater system • Relationship between static head (elevation), suction conditions, and pump performance • Meaning of net positive suction head (NPSH) for a centrifugal pump

💭 Think About

• Which component in the system is most sensitive to having enough pressure at its suction to avoid cavitation and loss of capacity? • How does the physical height of the DC heater above the next piece of equipment affect the pressure at that equipment’s suction? • Which of the listed choices would directly depend on elevation head, rather than on temperature control or gas properties?

✅ Before You Answer

• Be clear on what NPSH (Net Positive Suction Head) is and which piece of equipment needs it. • Identify which answer choices relate to pressure at pump suction vs those that relate mainly to temperature or gas conditions. • Confirm in your mind that increasing height of a tank above a pump increases static suction head and helps prevent cavitation.