A regulator for adjusting the pressure of a pressurized fluid wherein when a valve seat is fitted with a seat holder in a compressed state wherein excessive deformation of the valve seat due to a compressing reaction force is eliminated by the provision of a recessed groove is formed in the outer periphery of the valve seat. A compressing force by the seat holder is absorbed by compression deformation of the valve seat in the recessed groove portion of the valve seat.
The invention relates to an expansion valve and to a method for controlling an expansion valve, in which the opening and closing movement of the valve-closure member is set as a function of the pressure difference which is present in a feed opening on the high pressure side and in a discharge opening.
