🔍 Key Concepts

• Function of vent lines on main condenser water boxes • Effect of air pockets on heat transfer and pump operation • Relationship between circulating pump discharge pressure and trapped air in the system

💭 Think About

• Ask yourself what happens inside condenser tubes and water boxes if air is not removed. Does it affect water flow, heat transfer, or both? • Consider whether trapped air at the high points of a cooling-water system will mainly impact the pump’s discharge pressure, the tube cooling efficiency, or each in a different way. • Think about the primary design purpose of a vent line: is it to change pump pressure characteristics, to remove non‑condensables, to clear air locks, or some combination of these?

✅ Before You Answer

• Clarify whether air‑bound tubes reduce effective heat transfer area in the condenser. • Decide if circulating pump discharge pressure is mainly determined by system resistance and pump characteristics, or by venting air from the water box. • Check which of the given statements matches the primary reason designers add vent lines to the water box.