Sterling Inverted Bucket and Thermostatic Steam Traps

• Sterling Series 60 Inverted Bucket Steam Trap

• Sterling Series 19 Inverted Bucket Steam Trap

• Sterling Float and Thermostatic Steam Traps

• Sterling Series 7-50 Thermostatic Radiator Traps

Sterling Inverted Bucket

On start up, the bucket, by its own weight, rests on the trap bottom. The main valve is open, allowing the discharge of air and non-condensable. As condensate fills the body, it creates a seal on the open end of the bucket, which then becomes buoyant and rises, closing the main valve to discharge. Condensate, however, continues to enter the trap and force the air within the bucket our through the vent hole, causing it to lose its buoyancy and sink, opening the main valve to discharge. Condensate is discharged until steam reaches the trap and fills the bucket, which regains its buoyancy and the operating cycle is repeated.

Sterling Float & Thermostatic

A combination balance pressure thermostatic air vent and main float operated valve for condensate removal. Air initially had free access to discharge until surrounded by high temperature which closes the auxiliary vent. As condensate fills the trap body, the float rises, opening the main valve and discharging the condensate as it is received. The F&T is a fully modulating type trap that responds immediately or continuously to condensate discharge. The liquid level within the body is preset above the main valve, assuring that, when discharging, the orifice sees only liquid, thereby preventing the loss of live steam.

Sterling Thermostatic Radiator Traps

How The Sterling Thermostat Operates

A B

A. In a trap which is cold, or which is full of condensate below the boiler point, the Sterling thermostat remains compressed because of its internal  vacuum. The trap is open and condensate flows out.

B. Whenever live steam strikes the bellows, the water inside the thermostat starts to vaporize or boil. As soon as the steam pressure inside the thermostat becomes almost equal to the steam pressure surrounding the thermostat, the spring action of the bellows causes it to extend itself and close the trap. Because the thermostat is filled with pure water, the relationship of inside and outside pressures is always the same. This trap will always pass condensate and hold back steam in spite of any variations in steam pressure.

If the thermostat is damaged so that the bellows leaks, the vacuum inside the thermostat is lost. Then, whether the trap is hot or cold, it will remain closed. The location of the trouble will be easy to find because the radiator will be cold. Meanwhile, no steam is wasted.