I am not producing the correct answer which is 2.06 psia.

Question: The pressure gauge on the steam condenser for a turbine indicates 26.2 in. Hg of vacuum. The barometer reading is 30.4 in. Hg. What is the absolute pressure in the condenser in psia?

I know that 1 in. Hg = 0.4912 psia
And that
pabs = patm + pgauge
My answer was 27.8 psia
What am I doing wrong?

you should subtract the 26.2 from the barometric pressure. 26.2 in hg in vacuum means it is below atmospheric pressure.

To solve this problem, you need to convert the units correctly and follow the correct order of operations. Let's break down the steps to find the absolute pressure in the condenser:

1. Convert the pressure gauge reading from inches of mercury (in. Hg) to pounds per square inch absolute (psia). You correctly stated that 1 in. Hg is equal to 0.4912 psia.

p_gauge = 26.2 in. Hg * 0.4912 psia/in. Hg
p_gauge = 12.85544 psia (approximately)

2. Next, you need to calculate the barometric pressure in psia.

p_atm = 30.4 in. Hg * 0.4912 psia/in. Hg
p_atm = 14.96448 psia (approximately)

3. Finally, you can find the absolute pressure in the condenser by adding the gauge pressure to the atmospheric pressure.

p_abs = p_atm + p_gauge
p_abs = 14.96448 psia + 12.85544 psia
p_abs = 27.81992 psia (approximately)

Therefore, the absolute pressure in the condenser is approximately 27.82 psia. So, it seems like your calculation is correct. The correct answer is indeed 27.82 psia, not 2.06 psia as you mentioned.