172-65417MA-05 (FS21-L/FS21-H + BD2) 4 Oct 2021
5
Operation
Principles of air and condensate discharge:
1.
Air and Cold Condensate Discharge
at Startup
At startup, before steam is supplied,
the system is cold and the bimetal air
vent strip is contracted, holding the
float off the valve seat. This allows for
the rapid discharge of air and cold
condensate through the valve when
steam is first supplied to the system.
2.
Condensate Discharge
If the temperature of the condensate
rises above 90°C (194 °F), the bimetal
air vent strip expands allowing the
float to block the valve seat. Rising
condensate levels cause the float to
rise due to buoyancy, opening the
valve and allowing hot condensate to
be discharged.
3.
Closed Position
When the condensate flow rate
decreases, the float falls, closing off
the valve seat opening.
A water seal is maintained at all times
over the valve seat opening to prevent
steam loss.
Air
Steam
Condensate
