Refrigerant Flow Controls – Household
A Second generation, Frigidaire, automatic, adjustable expansion valve; housed in a 4 lb. solid cast brass body with galvanised over coat; with integral two point mounting bracket, inlet screen and Bakelite moisture proof cap; pressure actuated bellows design; engineered for sulphur dioxide or Freon 12 refrigerant; Model S, Frigidaire, circa 1934.
Technical Significance:
An advanced design expansion valves produced by Frigidaire, following their early experience in expansion valve engineering for dry evaporators.
Significant for the period was the calibration of the valve for alternate use on the then new series of chlorinated hydrocarbon refrigerants, Freon 12, as well as for sulphur dioxide.
Large inlet filter screen has also been provided on this model, a necessary feature for helping to ensure reliable, service free operation over extended periods of time.
Frigidaire moved to the use of a bellows pressure activating mechanism in this generation of valves, rather than the earlier diaphragm mechanism, following the trend.
A perennial, problem with such valves, experienced by Frigidaire and other manufacturers was freeze up do to moisture entering the valve through the manual adjustment mechanism. Frigidaire’s answer was, here, in the form of a condensation retarding, Bakelite cap, as an alternative to rubber and metal caps
