Air vents are
a) not required when an inverted bucket steam trap is used
b) not required on the steam mains if an inverted bucket steam trap is used at the steam coil
c) not required at the steam coil if a float and thermostatic (F & T) trap is used at the steam coil with an atmospheric return and the steam main is adequately vented
d) not required anywhere if a float and thermostatic (F & T) trap is used at the steam coil
e) required only with hot water coils
Answer: C