An expansion valve (1) for a vapor compression system, the valve (1) comprising a first valve part (5) having an outlet orifice (7) and a piston (8) movable inside the outlet orifice (7) in response to a differential pressure across the expansion valve (1), controlling a fluid flow through the valve (1). The piston (8) comprises a stop element (9) at an outlet end (8b) of the piston (8) and mechanical forcing means (10) to force the piston (8) towards a position in which the stop element (9) is brought into abutment with a valve seat (12) of the first valve part (5). A differential pressure below a predefined threshold value causes the stop element (9) of the piston (8) to abut the valve seat (12) of the first valve part (5), preventing fluid flow through the first valve part (5), via the forward fluid passage.

A hydraulic valve includes a biasing member for generating a biasing force to press a valve seat and a valve member. When a second hydraulic chamber has higher hydraulic pressure than a first hydraulic chamber, a hydraulic pressure difference between the first and second hydraulic chambers acts on the valve seat to separate the valve seat from the valve member against the biasing force of the biasing member so that the first hydraulic chamber and the second hydraulic chamber come into fluidal communication.