Abstract: In an expansion valve for controlling the flow rate of a refrigerant supplied to an evaporator of a refrigerating system, a temperature-sensing chamber is provided to sense the temperature of the refrigerant returning from said evaporator and to actuate a valve mechanism in order to regulate the flow of refrigerant supplied to said evaporator. An adsorption means provided inside the temperature-sensing chamber to adsorb a liquefied part of a gas charge within said chamber in order to hold said liquefied part away from warm wall parts inside said chamber. In addition, or as an alternative, said temperature-sensing chamber is separated from a return passage of said refrigerant by thermal-transfer-delay means for delaying the thermal transfer of a temperature change from the refrigerant to a sealed charge within said temperature-sensing chamber. Said thermal-transfer-delay means can be made as a flow restrictor for supressing an excessive flow between said chamber and said return passage of the refrigerant.

Abstract: An expansion valve (10) for controlling the flow rate of refrigerant supplied to an evaporator (1) of a refrigerating system comprises a temperature-sensing chamber (30) entirely provided within the housing (11) of said expansion valve in a low pressure passage (12) thereof. Said passage (13) is connected to the outlet of said evaporator (1) and the inlet of a compressor (2), for converting a temperature change into a pressure change in order to actuate a valve mechanism (20) in response to a rise and lowering in pressure of said temperature-sensing chamber to open and close a passage (13) for adiabatic expansion of the refrigerant. Said temperature-sensing chamber (30) contains a sealed gas charge and an adsorbent material (35) for adsorbing and releasing said gaseous medium in accordance with temperature changes sensed.