5
Operation
Principles of air and condensate discharge:
1. Start-up Air and Cold Condensate
Discharge
At start-up, before steam is supplied, the system is
cold and the bimetal air vent strip is expanded,
holding the float off of the orifice. This allows for
the rapid discharge of air and cold condensate
through the orifice when steam is first supplied to
the system.
2. Condensate Discharge
As steam is supplied, hot condensate flow begins.
When condensate temperature becomes 90°C
(194°F) or higher, the bimetal air vent strip
contracts, allowing the float to close off the orifice.
However, the rising condensate level causes the
float to rise due to buoyancy, opening the orifice
and allowing hot condensate to be discharged.
3. Closed Position
When the condensate flow rate decreases, the
float falls, closing off the orifice opening. A water
seal is maintained at all times over the orifice to
prevent steam loss.
Air
Steam
Condensate
172-65486MA-00 (SH5VL) 5 Sep 2012
