Air Vents on Shell & Tube Heat Exchangers
On start-up, the heat exchanger and connected piping is filled with air which must first be discharged thru Air Vents to allow steam to enter for
heating. Float & Thermostatic steam traps contain a separate thermostatic vent, and can discharge much of the air present during system startup,
however some air will remain trapped in the heat exchanger to remove this trapped air. Additional air vents need to installed on the heat exchanger.
The faster air is expelled, the faster steam can enter and heating can begin.
System without an Air Vent
The diagrams below show the heat exchanger without a proper air vent at the high point in the heat exchanger.
System with an Air Vent
The diagrams below show the heat exchanger with a proper air vent at the high point in the heat exchanger.
Air Vents on Steam Jacketed Kettle System
On start-up, jacket is filled with air which must first be discharged by the Air Vents to allow steam to enter for heating. Float & Thermostatic steam
traps contain a separate thermostatic vent, and can discharge large volumes of air present during system startup. Additional air vents may be installed
on the kettle. The faster air is expelled, the faster steam can enter and heating can begin.
System without an Air Vent
The diagrams below show the steam jacketed kettle without a proper air vent at the high point in the heat jacket.
System with an Air Vent
The diagrams below show the steam jacketed kettle with a proper air vent at the high point in the heat jacket.
Air Vents on Steam Mains
Air Vents are installed at the end of steam mains as well as other high points in the system. The Air-Vent reacts to temperature changes and is OPEN
when cooler air is present and CLOSE when hot steam enters the system.