About how many inches (in) of mercury (Hg) should the vacuum in the main condenser be?

About how many inches (in) of mercury (Hg) should the vacuum in the main condenser be?

• A. 29
• B. 15
• C. 50
• D. 0

Answer: (A)

A strong vacuum in the main condenser is needed to condense the exhaust steam efficiently and keep turbine back pressure low. This vacuum is measured in inches of mercury (Hg), with higher numbers indicating a lower pressure inside the condenser. In naval condensers, the target is near full vacuum, typically around 29 inches of Hg. That level provides effective condensation and optimal generator/turbine performance. A reading around 15 inches would be a weaker vacuum and reduce efficiency, while 0 inches means no vacuum at all. A value like 50 inches isn’t attainable with this scale. So, about 29 inches of mercury is the appropriate target.

A strong vacuum in the main condenser is needed to condense the exhaust steam efficiently and keep turbine back pressure low. This vacuum is measured in inches of mercury (Hg), with higher numbers indicating a lower pressure inside the condenser. In naval condensers, the target is near full vacuum, typically around 29 inches of Hg. That level provides effective condensation and optimal generator/turbine performance. A reading around 15 inches would be a weaker vacuum and reduce efficiency, while 0 inches means no vacuum at all. A value like 50 inches isn’t attainable with this scale. So, about 29 inches of mercury is the appropriate target.