[banerj1s]

Do you mean heater drain system? Deaerator normally blows down to atmospheric tank. The line doesnt need a steam trap.
Also the same for overflow line. Deaerator has a level control system. This is a critical control point or trip level control point. I am not sure if overflow line is required. If it is a coal plant there shall be a heater drain system which will relieve the water to cascading drain system.

Cheers