Steam traps are valves used in steam pipe networks and equipment to automatically discharge condensate, air and other non-condensable gases, and to prevent steam leakage. According to the working principle of a steam trap, its general working steps are as follows.

1. The steam trap is installed between the steam heating equipment and the condensate return header. When starting, the barrel is at the bottom and the valve is fully open. The condensate enters the trap and flows to the bottom of the barrel, filling the valve body, completely submerging the barrel, and then the condensate is discharged to the return header through the fully open valve.

2. Steam also enters the trap from the bottom of the barrel and occupies the top of the barrel body, generating buoyancy. The barrel slowly rises and gradually moves the lever in the direction of the seat until the valve is completely closed. Air and carbon dioxide gas pass through the exhaust holes in the barrel and collect at the top of the trap. The steam that exits from the vent hole condenses due to heat dissipation from the trap.

3. When the incoming condensate starts to fill the barrel, the barrel starts to exert a pull force on the lever. As the condensate level rises, the resulting force increases until it is possible to overcome the pressure difference and open the valve.

4. When the valve starts to open, the differential pressure acting on the disc decreases. The barrel will be lowered rapidly, allowing the valve to be fully open. The non-condensable gas that accumulates on the top of the trap is discharged first, and then the condensate is discharged. When the water flows out of the barrel, the dirt flows out of the trap together. At the same time as the condensate is discharged, the steam starts to enter the trap again, and a new cycle begins.